[cctalk] Re: Lunar Lander, bug

[John Robertson via cctalk]

On 2024/06/17 12:26 p.m., Ethan Dicks via cctalk wrote:

On Mon, Jun 17, 2024 at 1:53 PM Mike Katz via cctalk
  wrote:

I remember running this program at school in the mid 1970's.

This runs on 4K Focal '69 without the extended functions enabled. So it
should run on a 4K PDP-8/L.

...

It was available as FOCAL8-81 from DECUS (Submitted 20-Jan-1970):

https://svn.so-much-stuff.com/svn/trunk/pdp8/src/decus/focal8-81/

I have run this at VCF on a 4K PDP-8.

-ethan


Fascinating - and there was a video game made by Atari called Lunar 
Lander which also tried to put a LEM safely on the surface.


Some more of the history of the games (from 2009):

technologizer.com

Forty Years of Lunar Lander <#>

Lunar Lander games abound on every platform. Along with Tetris and 
Pac-Man, the game--in which your mission is to safely maneuver your 
lunar module onto the moon's surface--is one of the most widely cloned 
computer games of all time. But did you know that game players began 
touching down on the moon in Lunar Lander…


 https://technologizer.com/2009/07/19/lunar-lander/index.html 



 John :-#)#


--
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7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
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 "Old pinballers never die, they just flip out"

[cctalk] Re: IBM 360

[John Robertson via cctalk]

On 2024/04/09 7:53 p.m., Murray McCullough via cctalk wrote:

I had not realized the IBM 360 was 60 yrs. old this month. I worked on such
a computer in the late 60s in Toronto. What one could do with 8 Kbytes of
ram was remarkable!

Happy computing

Murray 


One of my early summer jobs as a teenager (19?) was at IBM in Toronto - 
stripping old noise reduction foam from card punch machines so they 
could get sandblasted and repainted...also in the very late 60s.


John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Double Density 3.5" Floppy Disks

[John Robertson via cctalk]

On 2024/04/30 10:08 a.m., Anders Nelson via cctalk wrote:

Having grown up with 1.44MB 3.5" floppies, I have a question: is it
possible to use a 1.44MB disk and just format it as a 720K disk?

=]
--
Anders Nelson
www.andersknelson.com


As I recall you had to bulk erase the old diskette and then you could 
format it as 720 - covering the 1.44 hole of course.


Not bulk erasing (the side of a Weller soldering gun works just fine) 
led to erratic results. We all have Weller guns for fixing computers, eh?


John :-#)#




On Tue, Apr 30, 2024 at 1:00 PM Mike Katz via cctalk 
wrote:


Does anybody have any extra 720K (double sided, double density) 3.5"
Floppy Disks that could use a good home?

If so, please email me directly at bit...@12bitsbest.com.

Thank you,

   Mike



--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: typical IC kits on Amazon and elsewhere

[John Robertson via cctalk]

On 2024/03/30 7:53 p.m., Glen Slick via cctalk wrote:

On Sat, Mar 30, 2024 at 5:11 PM Jonathan Chapman via cctalk
 wrote:

Standard TTL 74XXX is drying up rather quickly. Futurlec still has some
TTL but 7404s are all gone. Even LS is hard to find.

Ours comes from Mouser, between two part #s they have over 7,000 74LS04s in DIP 
packaging in stock. Didn't check ACT, HCT, or ALS. I don't think we've had a 
7400 series part that we couldn't just order off Mouser in recent history, and 
we're usually buying QTY 100.


You can also buy parts direct from TI, for example they currently show
around around 3000 SN74LS04N parts in stock.

https://www.ti.com/product/SN74LS04/part-details/SN74LS04N

The prices for that part match the current Mouser prices of $0.674
each, or $0.519 each if you buy at least 4 tubes of 25 parts.

I've bought some tubes of 74LS parts direct from TI in the last year.


Interesting, but does TI offer free international shipping with import 
duties & taxes covered if you order over $100US?


John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: FW: Re: ADM3a screen rot.

[John Robertson via cctalk]

On 2024/01/29 12:45 p.m., William Sudbrink via cctalk wrote:

Sellam Abraham wrote:


I think you were fine.  That's how you discharge them anyway.  You were just 
missing the grounding wire :)

Yes, I have one set up for just that purpose.  Wire clamped to the shaft with 
an alligator at the other end.
But I was so pissed off, I just grabbed a screwdriver off of my workbench.  I'd 
rather not be the electron sink
In this case.  I've never taken a hit off of a CRT have you?

Bill S.


I had a chat with an electrical engineer about discharging old picture 
tubes many years ago, and he highly recommended using a suitable 
resistor array - like a HV probe to drain the charge on B monitors. 
Particularly ones that had a separate HV diode. He told me that 
discharging with a screwdriver can pass too much current (caused by a 
cascade of charges) through the diode array and damage them.


This explained a problem we were having with B XY monitors made by 
Electrohome and Wells Gardner where the diode that was mounted between 
the HV transformer and the picture tube would fail and run hot, over 
heating the silicon rubber caps on the ends. I've not lost any HV diodes 
on machines since using our HV probe to discharge since that time.


John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Looking for 1970s OAK keyboard switches...

[John Robertson via cctalk]

On 2024/01/25 6:28 a.m., Paul Koning wrote:



On Jan 24, 2024, at 3:52 PM, John Robertson via cctalk  
wrote:

I've been hunting for a while now for OAK PCB mount keyboard switches that I 
can't find a part number for. I've attached a product listing for the switch 
that shows it pretty well. DPST-NO preferred.

Only $0.40 in the early '70s!

I don't know about Oak, but I remember that Cherry switches were still 
available (new) fairly recently.  A friend of mine used them to build replica 
PLATO keyboards -- using the same switches that were in the original.

paul

Cherry switches are quite different in size and mount from the ones I'm 
looking for unfortunately.


John :-#(#

[cctalk] Re: Looking for (WTB:) 1970s OAK keyboard switches...

[John Robertson via cctalk]

On 2024/01/24 12:52 p.m., John Robertson via cctalk wrote:
I've been hunting for a while now for OAK PCB mount keyboard switches 
that I can't find a part number for. I've attached a product listing 
for the switch that shows it pretty well. DPST-NO preferred.


Only $0.40 in the early '70s!

Any quantity considered...

Thanks!

John :-#)#

I see attachments aren't permitted, even on of only 70k. When did that 
stop - going back in my archives I see messages from the early 2000s 
that had small attachments. Oh well, I'll make some links:


https://www.flippers.com/images/Misc/OAK_Pushbutton_Switch-1973.jpg

https://www.flippers.com/images/Misc/OAK_MysterySwitchAd.png

Anyone seen any of these? They were used in the first Computer Space 
games...(so on topic - ducking!)


Thanks!

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Looking for 1970s OAK keyboard switches...

[John Robertson via cctalk]

I've been hunting for a while now for OAK PCB mount keyboard switches 
that I can't find a part number for. I've attached a product listing for 
the switch that shows it pretty well. DPST-NO preferred.


Only $0.40 in the early '70s!

Any quantity considered...

Thanks!

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: FYI: Hobbes OS/2 Archive logs off permanently in April

[John Robertson via cctalk]

On 2024/01/10 10:56 a.m., Dennis Boone via cctalk wrote:

  > According to a warning on the site: "After many years of service,
  > hobbes.nmsu.edu will be decommissioned and will no longer be
  > available. You the user are responsible for downloading any of the
  > files found in this archive if you want them. These files will no
  > longer be available for access or download as of the decommission
  > date."

Jason Scott has indicated he has archiving under control.

De


I would also suggest you get archive.org in on it...

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: PDP 11/34 or 11/04 front panel question

[John Robertson via cctalk]

On 2023/12/19 4:26 a.m., Tom Hunter via cctalk wrote:

I just realised that I never followed up on this.

After some research and a few phone calls to manufacturer support lines I
settled on SikaBond SprayFix as the glue.

...

The front panel has now been re-assembled and is fully functional and
beautiful.   :-)


Might you have Before and After photos?

Sounds like this is a useful product to have in the shop!

Thanks,

John :-#)#



On Tue, Nov 7, 2023 at 9:33 AM Tom Hunter  wrote:


The PDP 11/34 and 11/04 front panels (both operator and programmer) use a
somewhat stiff plastic sheet of 1.0 mm thickness with DEC logo, model
designation, labels for the keys printed on it, cut-outs for the keypad and
knob and red transparent sections for LEDs and 6 digit 7-segment display.

I don't know what the industry calls this type of plastic sheet? Is it a
"decal"???

This plastic sheet is (was) fixed to an anodized aluminium plate (1.6 mm
thickness) using some type of glue which has deteriorated so that the
plastic sheet has separated from the aluminium plate.

The glue looks like it has been sprayed on and has a light yellowish-brown
appearance. The glue readily dissolves in ethyl-alcohol and acetone, but is
unaffected by water, petrol (gasoline) and dry cleaning fluid (white
spirits).

I would like to glue the plastic sheet back onto the aluminium plate, but
worry about damaging the plastic sheet and/or paint by the solvents in
typical glues.
Also some glues don't allow any adjustment once you combine the two halves
of whatever you glue together.

What type of plastic is this plastic sheet likely made of (polycarbonate?)
and what paint was used? I am asking to determine what solvent based glues
may attack either the plastic sheet or the painted surfaces.

The dark grey and transparent red paints are applied to the back side of
the plastic sheet, so they are vulnerable to solvent attack when glueing. I
tried ethyl-alcohol in one corner which is obscured by the cast metal
surround and some of the dark gray colour came off with the alcohol and
gentle rubbing.

Has anyone successfully glued back the plastic sheet to the aluminium
plate? If yes, what type of glue did you use and how exactly did you do the
operation?

Any suggestions, advice or tips?

Thanks and best regards
Tom Hunter




--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Free to good home HP 7510a Photo Plotter - UK

[John Robertson via cctalk]

Location?

On 2023/11/16 2:24 a.m., Dave Wade G4UGM via cctalk wrote:

Folks,

  


Trying to reduce the weight in my loft and I would like to donate my HP
Photoplotter to a good home.

. Photos of the plotter and some sample plots are on my OneDrive here:-

  


https://1drv.ms/f/s!Ag4BJfE5B3ongspXY7zySSZsDj-WMg

  


It has both serial and IEEE interfaces and uses HPGL like the GP and Roland
pen plotters.

The plots on there are the samples built into the plotter taken on a Fuji
XE-1 digital camera and are cropped because the Fuji does not have a full
frame sensor.

The tube is actually a white tube and the colours are generated by rotating
colour filters.

Its powered by a 68000 and you can see the various boards in the pictures.

  


Dave

  

  



--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: ROM data for Lear Siegler ADM31?

[John Robertson via cctalk]

Hi Peter,

Thanks, I'll check with Ian if he tried those or not...

John :-#)#

On 2023/08/03 11:58 a.m., Peter Ekstrom wrote:

Hi John,

Would these be what you are looking for?

https://bitsavers.org/pdf/learSiegler/ADM_31/firmware/

-Peter

On Thu, Aug 3, 2023 at 2:47 PM John Robertson via cctalk 
 wrote:


I sold my Lear Siegler ADM31 recently and the new owner (Ian) has
found
that one of the ROMs failed before he could archive it - or it was
defective to start with.

So my question to the list is - does anyone have the ROM codes (there
are three of them) archived?

I don't think Ian is a member of this list, otherwise I'm sure I
would
have spotted a post with a subject line like mine...

Thanks!

John :-#)#

-- 
                  John's Jukes Ltd.

7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
flippers.com <http://flippers.com>
  "Old pinballers never die, they just flip out"



--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] ROM data for Lear Siegler ADM31?

[John Robertson via cctalk]

I sold my Lear Siegler ADM31 recently and the new owner (Ian) has found 
that one of the ROMs failed before he could archive it - or it was 
defective to start with.


So my question to the list is - does anyone have the ROM codes (there 
are three of them) archived?


I don't think Ian is a member of this list, otherwise I'm sure I would 
have spotted a post with a subject line like mine...


Thanks!

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Don Lancaster has passed away at 83

[John Robertson via cctalk]

On 2023/07/01 1:10 p.m., Sellam Abraham via cctalk wrote:

Don Lancaster passed away on June 7.

https://gilaherald.com/obituary-for-don-lancaster/

I hope his website is well preserved:

https://tinaja.com/

Sellam


web.archive.org has many copies archived:

https://web.archive.org/web/202300*/https://tinaja.com/

A sad day none the less.

John

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Recovering floppies attacked by mould

[John Robertson via cctalk]

On 2023/05/25 5:11 p.m., Sellam Abraham via cctalk wrote:

Tom,

You may save yourself some time with this nifty contraption ==>
https://www.ebay.com/itm/303620862566

It's a floppy disk cleaning apparatus.  You place the floppy disk into the
frame, apply your cleaning solution and cloth to the index opening, and
then manually spin the disk.

Sellam


If you have a 3D printer then Thingiverse has 3.5 and 5.25 inch floppy 
cleaner files:


https://www.thingiverse.com/search?q=floppy+disc+cleaner=1=things=relevant

John :-#)#



On Thu, May 25, 2023 at 3:36 PM Tom Stepleton via cctalk <
cctalk@classiccmp.org> wrote:


Greetings,

Amidst all the floppy archiving discussion, here's a slightly different
question:

The weather is warmer now where I live, so it's starting to be a good time
to do messy work outdoors. I have some mouldy floppy diskettes that I'd
like to try to read (mostly 5.25"), plus a good flux reader. What is the
best way to attempt to image these floppies?

My thinking right now is that for each floppy I can attempt this procedure:
- remove the mouldy cookie from the infected disk jacket; discard the
latter
- give the cookie the best clean I can (how?) and allow to dry
- place the cookie in a clean disk jacket
- attempt to image
- clean floppy drive heads

Does this seem like a sensible plan? If so, what would be the best way to
clean as much mould off the cookie as I can? Tools that come to mind are
distilled water (tap water here is full of chalk), dish soap,
cyclomethicone, and of course more fearsome solvents. I have kimwipes,
microfibre cloths, and... 200-grit sandpaper, I guess :-)

Thanks for any advice,
--Tom



--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Schematics for Lear Siegler ADM31?

[John Robertson via cctalk]

On 2023/04/23 3:16 p.m., Glen Slick via cctalk wrote:

On Sun, Apr 23, 2023 at 3:10 PM John Robertson via cctalk
 wrote:

Oh, I am missing two key caps for the ADM31, anyone have spares? Not
sure what is printed on them at this point, but any caps would be better
than missing ones to start!

Keyboard photo to see what key caps are missing:

https://terminals-wiki.org/wiki/index.php/Lear_Siegler_ADM-31
https://terminals-wiki.org/wiki/images/2/29/Lear_Siegler_ADM-31_321477505131-3.jpg


As I remember (machine is at shop, and I'm not) I am missing the top row 
far left - DEL/CHAR/INS - and the top row right of that section - SKIP.


I need to confirm on Tuesday, but that link is a major help!

Thanks,

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Schematics for Lear Siegler ADM31?

[John Robertson via cctalk]

On 2023/04/18 8:48 p.m., Tony Duell via cctalk wrote:

On Wed, Apr 19, 2023 at 2:37 AM Tom Hunter via cctalk
 wrote:

... or four $20 power transistors to protect a 10 cent fuse like on the DEC
VR-14 display.

In general the transistor(s) will fail short-circuit, thus taking out
the fuse too.

Some switch-mode power supplies use special fast-acting fuses which
can actually be more expensive than the chopper transistor.

-tony


In the end replacing the capacitors got the supply running. And I 
checked the resistor that looked overheat, and it was 34R which is 
within 15% of the value shown on another 1001 supply that is close to 
the one (same part numbers and values for a number of the parts) in my 
ADM31.


The supply puts out +5VDC, +17VDC (unreg), -17VDC (unreg), and 70VDC 
(unreg).


The board appears to work - I have 5VDC on the MB, and I get a BEEP, and 
there is some sort of data happening on the DB and I am getting data on 
the Vertical, Horizontal, and Video signals to the monitor. Monitor 
isn't lighting up - no HV (I've recapped it too), so I have to put on my 
monitor hat next.


Stay tuned if interested...

Oh, I am missing two key caps for the ADM31, anyone have spares? Not 
sure what is printed on them at this point, but any caps would be better 
than missing ones to start!


Thanks,

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: flipchip cleaning and pin corrosion inhibition

[John Robertson via cctalk]

On 2023/04/23 10:00 a.m., Paul Koning via cctalk wrote:



On Apr 23, 2023, at 12:54 PM, Fritz Mueller via cctalk  
wrote:

Hi folks,

I’ve been picking my way through a PDP-8/L restoration lately.  I’ve found that 
everything in the machine is covered with a uniform layer of dark “soot” 
(enough to blacken your hands while working with it) which I would like to 
clean up.  Perhaps the “soot” is actually from a decomposed air filter, as I 
don’t imagine this machine was operated in a smoky environment, and there is no 
smoke odor.

I usually use 99 IPA and cleanroom wipes for spot cleaning these sorts of 
things, but in this case there is so much of it that I feel that would just 
push the soot around rather than clean it off.  I think some sort of actual 
rinse would be needed here.

I’ve been eying the dishwasher, for the subset of flip chips that that are just 
DIP logic, carbon comp resistors, and ceramic bypass caps, anyway.   But I 
haven’t been brave enough to try that yet...  Most of the logic here has date 
codes to ’68 or ’69, so I’m inclined to treat it gently.  Any suggestions for 
approaches to clean this up?

Dish washer soap may be caustic.  Detergent for washing dishes by hand may be a 
better choice.


Follow-on question: the majority of the legs on these old DIPs are showing what 
I’d call “moderate” corrosion — nothing looks like it is in danger of being 
eaten all the way through, but the process is underway.  I was wondering if 
something like a light shellac or other inhibitor could be brushed over these 
pins to at least slow their inevitable demise?

I wonder if you might be seeing corrosion caused by leftover flux.  Modern flux can be of the "water 
soluble" kind, which indeed washes away nicely with warm water; I've used that for surface mount 
projects.  The traditional flux is rosin flux.  That can be removed with a solvent but that wasn't 
necessarily done.  Amateur project built with that typically would not be cleaned, and that was generally 
considered ok.  A bit like modern "no clean" flux.  But flux is somewhat corrosive, and "no 
clean" may mean simply that it's not an issue within the life expectancy of the device.  So -- you might 
see if rosin flux remover does anything.

paul

I use Dow Corning #4 Dialectic Grease to reduce or prevent corrosion on 
power and signal connectors. Read the spec sheets on that stuff, it is 
really good for metal on metal connections. I imagine it would work well 
on those silver alloy IC legs that are gradually oxidizing away...


John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Schematics for Lear Siegler ADM31?

[John Robertson via cctalk]

On 2023/04/18 9:40 a.m., Tony Duell wrote:

On Tue, Apr 18, 2023 at 2:51 PM Tom Hunter via cctalk
 wrote:

The blown out resistor likely has "blown out" for a reason.
The replacement will probably suffer the same faith unless you find the
root cause.


As soon as I saw 'Boschert' mental alarm bells triggered

Boschert made a particularly unfriendly (to the repairer) type of
SMPSU which I call the '2 stage'. I can explain how it works if
necessary, but be warned that with one of those if a particular power
transistor fails (and it often does), it takes out a couple of other
power transistors, the current sense resistor, numerous small
transistors, the regulator chip, the fuse and sometime PCB tracks.

They're not all like that, but I will agree that a burnt-out resistor
in an SMPSU nearly always means other components have failed.

It's likely the same PSU was used in other devices, you might want to
look through all the service manuals you can find to see if it turns
up. Can you make a photo of the PSU available somewhere in case
somebody recognises it.

-tony


I like to start with schematics before poking too much...

Photo of the SMPSU:

https://www.flippers.com/images/ADM31_Terminal/Boschert_1001_ADM31_PowerSupply.jpg

Burnt Resistor:

https://www.flippers.com/images/ADM31_Terminal/Boschert_1001_ADM31_PowerSupply-burnt_resistor.jpg

Schematics preferred, under the power supply is one I found on bitsavers 
for a slightly later model terminal. If needed I will draw them up 
myself, I just don't want to spend a couple of hours sketching it out if 
I can find a proper drawing.


I assume bad caps (will replace with low-ESR high temp), and possibly 
blown transistor(s)...


*And Gregory Beat sent me a link that covers the 1001 SMPS very neatly:*

http://www.bitsavers.org/pdf/boschert/Boschert_OL25_Single-Stage_Power_Supply_Maintenance_Manual_May79.pdf

and it was buried on bitsavers - where I went before bothering the list!

Thanks folks!

John :-#)#






On Tue, Apr 18, 2023 at 12:20 AM John Robertson via cctalk <
cctalk@classiccmp.org> wrote:


I've checked bitsavers.org (Al does a great job!), and a number of
forums, but no luck finding schematics for my ADM31 that I am trying to
resurrect. The power supply has issues and I need to identify a blown
out resistor - the switching supply is a Boschert model 1001 date code
7943 Revision J.

John :-#)#

--
John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
flippers.com
"Old pinballers never die, they just flip out"




--
  John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
  flippers.com
  "Old pinballers never die, they just flip out"

[cctalk] Schematics for Lear Siegler ADM31?

[John Robertson via cctalk]

I've checked bitsavers.org (Al does a great job!), and a number of 
forums, but no luck finding schematics for my ADM31 that I am trying to 
resurrect. The power supply has issues and I need to identify a blown 
out resistor - the switching supply is a Boschert model 1001 date code 
7943 Revision J.


John :-#)#

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 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: HP9825A for sale

[John Robertson via cctalk]

On 2023/04/17 9:12 a.m., Sellam Abraham via cctalk wrote:

My initial reaction is that $2,000 seems a "bit" optimistic.

That being said, I'm surprised to see (on eBay's Terapeak) a couple of
these sold within the past year for around $1,100.

Sellam


One sold on eBay for $2492USD...Apr 6, 2023:

https://www.ebay.com/itm/225512121074?hash=item348191e2f2

John :-#)#



On Mon, Apr 17, 2023, 8:52 AM Steve Lewis via cctalk 
wrote:


There is a gentlemen in New Jersey willing to sell his HP9825A

I believe he is the original owner.  It has 4 ROM cartridges (that go in
the front) and several data cartridges for the slot on the top left.

He is asking $2000 but can probably negotiate (as he didn't find any takers
in VCF East).  As far as he knows, everything still works (LED lights came
on when he powered it up a few months ago).

I've met this seller and can vouch for him, but I don't know much about
this particular item.

I have some photos of it at the bottom of this page:
https://voidstar.blog/vcf-east-2023-part-3/

I may try a VCF forum topic about it.  Just trying to help him find a good
home for the equipment.  E-mail/reply direct and I can provide some contact
info.

(BTW not sure if my cctalk posts are working anymore??)

-Steve / voidstar



--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Looking for EPROMs

[John Robertson via cctalk]

On 2023/03/27 2:10 p.m., Mark Linimon via cctalk wrote:

On 03/27/2023 5:38 PM GMT rescue via cctalk  wrote:
have a number of 2764, 27256, have some 27128 I think too

Myself as well, probably down to 1702s.  Right now with some current money
trouble they are looking like assets :-/

mcl


I'm looking for 100 lot quantities of 2716s...something a bit better 
than the Chinese remarks (and very thin legs) would be nice!


Thanks!

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] NOS Tapes 3 X 3M DC 600A 60MB Cartridges (1991)...(speaking of tapes)

[John Robertson via cctalk]

Anyone interested in 3 tapes - has Olympics logo - still in original 
wrapping? Ether pick up at my shop or pay for postage and handling...


John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Identifying a Failed Diode in a Rainbow H7842 Power Supply

[John Robertson via cctalk]

On 2022/11/27 1:21 a.m., Rob Jarratt via cctalk wrote:

I have done a little more probing around. I have found that the 7812 regulator 
that drives Vstart on sheet 1 of Tony Duell’s schematic is shorted, so I will 
have to replace this too. I have not found anything else that looks obviously 
suspicious. I can’t test the output rectifiers for shorts without desoldering 
them, which I would rather avoid. I guess the next step is to replace the 
broken parts and use the light bulb current-limiter method to power on the PSU.

Regards
Rob


My experience with blown 7812s is that there was a surge on the 
unregulated side that went over the maximum input rating for the device. 
You may want to add a Transient Suppression Diode on the input if this 
is a future possibility or a suitable line protection MOV on the input 
just after the line fuse.


John :-#)#

  


From: Rob Jarratt 
Sent: 24 November 2022 21:45
To: 'Mattis Lind' ; r...@jarratt.me.uk; 'General Discussion: 
On-Topic and Off-Topic Posts' 
Subject: RE: [cctalk] Identifying a Failed Diode in a Rainbow H7842 Power Supply

  


Thanks for the suggestion Mattis. The UF4007 has a PIV of 1000V, I had a 
suggestion that the PIV should be 200V. Not sure what rating I should be going 
for here?

  


Regards

  


Rob

  


From: Mattis Lind mailto:mattisl...@gmail.com> >
Sent: 22 November 2022 07:54
To: r...@jarratt.me.uk  ; General Discussion: On-Topic and 
Off-Topic Posts mailto:cctalk@classiccmp.org> >
Subject: Re: [cctalk] Identifying a Failed Diode in a Rainbow H7842 Power Supply

  

  


Hello Rob!

  



Given that before the transistor blew up there had clearly been another
failure somewhere else, I tried to find the original failure. There were no
obviously damaged parts, so I just probed around near the transistor for any
parts that were open circuit or short circuit. I found a diode connected to
the base of the transistor that appeared to be short circuit. So, I decided
to lift one end to check it. As I de-soldered one of the leads, the diode
broke in two. So clearly the diode was either damaged by the failure of the
transistor, or it was the cause of the failure. This is the diode:
https://rjarratt.files.wordpress.com/2022/11/img_20221120_165913.jpg.

  

  


DEC used a lot of A114x diodes in their PSUs. They looked exactly like that 
one. Those are fast recovery diodes. 
https://pdf2.alldatasheet.com/datasheet-pdf/view/7563180/2074/A114F.html

  


I would replace it with a UF4007 or something similar. 
https://www.mouser.se/datasheet/2/849/uf4001-2578577.pdf

  

  

  



I can't quite make out the markings on the diode to know what to replace it
with. I think it says "D610". Would that be the right designation? If so,
can anyone suggest a suitable replacement please?



The diode seems to connect an inductor to the base of the switching
transistor and the collector of the transistor is connected to a
transformer. Should I be looking for other failed parts? Not sure if the
diode failed first and then caused the transistor to fail? Or if something
else has failed which caused these parts to fail?

  

  


Also check all other semiconductors. Also on the outputs. If there is a 1 ohm 
fusible resistor in the base drive circuit check that one as well. In the VT100 
PSUs it happens that it blows.

  

  





I do know that there are no shorts in the Rainbow itself, because I have a
spare PSU that still works fine in the same machine.



I blogged this here (it repeats most of that I have said above):
https://robs-old-computers.com/2022/11/20/dec-rainbow-h7842-power-supply-fai 

lure/

  


/Mattis


Thanks



Rob



--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: Shipping help in Brunswick, GA

[John Robertson via cctalk]

On 2022/11/06 8:37 p.m., John H. Reinhardt via cctalk wrote:
So, I screwed up and in my excitement to find a DEC BA123 chassis (and 
MVII parts) I bid on an Ebay auction where there is no shipping and 
it's "Local Pickup Only".  The problem is that I'm near Fort Worth TX 
and the MVII/BA123 is in Brunswick, GA and I don't really have the 
time to make the 2000+ mile round trip drive to pick it up.


Does anyone here know of a reliable shipping service in Brunswick, 
GA?  Or suggestions for outfits to check out?  Google hasn't shown me 
much other that UPS and FedEx stores.


Failing that, is there anyone near enough willing to pick it up in 
Brunswick that might want it for themselves?


Ebay listing  https://www.ebay.com/itm/334615827742?

If they can put it on a pallet then you can find a Freight Forwarder in 
the area that can arrange a pickup...


Or contact North American Van Lines (NAVL-Beltman) Michele Bianchi 
(630-344-3093) there arranges pickups of equipment (like arcade games 
for home owners) in similar situations. This service isn't as cheap as 
trucking would be from a Freight Forwarder.


Good luck!

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)

[John Robertson via cctalk]

On 2022/09/19 9:51 p.m., ben via cctalk wrote:

On 2022-09-19 10:18 p.m., Tom Hunter via cctalk wrote:

There are a few US based Ebay sellers of the 74L85.

Tom

But most ebay sellers, from the USA seem to sell a item for $6.00 and
$75 shipping to Canada. China $2 and $3 shipping. With Covid all 
shipping is several weeks.

Ben.

How many do you need? I have one or more of 74LS85, 74C85, 74HC85, and 
7485...


Email me directly with which version you prefer. These are all NOS 
parts, not pulls.


John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)

[John Robertson via cctalk]

Ben, I buy lots of stuff from eBay US sellers and most are willing to check/fix 
shipping costs. 
If not then I use a drop-box service where the item is shipped to Oregon, and 
then reshipped to me for a not too horrible cost. 

Lastly, I’ll be back at my shop in Burnaby in a couple of days and can check my 
inventory of TTL chips - might well have your 74L85, and postage is pretty 
cheap within Canada. I’ll try not to hose you too badly on the chip cost!

John :-#)#

> On Sep 20, 2022, at 5:52 AM, ben via cctalk  wrote:
> 
> On 2022-09-19 10:18 p.m., Tom Hunter via cctalk wrote:
>> There are a few US based Ebay sellers of the 74L85.
>> Tom
> But most ebay sellers, from the USA seem to sell a item for $6.00 and
> $75 shipping to Canada. China $2 and $3 shipping. With Covid all shipping is 
> several weeks.
> Ben.
> 
> 
> 

Re: Retire cctech

[John Robertson via cctalk]

On 2022/07/13 3:00 p.m., Dennis Boone via cctalk wrote:

Folks,

I've belatedly realized that it's going to be a bit of a headache to
implement the old cctalk/cctech crossposting duality under the new
version of mailman.

I seem to recall a discussion about retiring the cctech list and just
continuing with cctalk, and that the consensus was in favor of that.

I'll call this message a consent agenda indicating that I plan to do
that, unless there's loud outcry.

De


Are the old posts all archived and searchable? I have a gap from 2016 
through 2022, and before that it is complete back to Mar 29, 2007 (I 
think it is complete).


Merging makes sense to me.

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

Re: OT: mail provider recommendation

[John Robertson via cctalk]

There ain’t no such thing as a free lunch!

What did you think would happen with large free email hosts? They round up all 
the clients and then do what they like with them. 

Google mines emails for data.

I use a private (paid) service via my web site host. I’ve been using it since 
around 1996.

They haven’t changed much over the decades and they do NOT mine my emails!


> On Jun 10, 2022, at 10:01 PM, Carlos Murillo via cctalk 
>  wrote:
> 
> My apologies for asking such an OT question, but I think you guys are the
> most likely to make really useful suggestions.
> 
> Gmail has ceased to provide classic authorization for  smtp, pop3 or IMAP
> access; they want users to employ their new authorization mechanisms.  So,
> which email service do you guys recommend? I'd like to be able to access it
> in the old classic way, from different clients. Ideally it would be a free
> service (I don't store my messages on the server, but rather, download them
> to my client, so I don't need a lot of storage), and also likely to remain
> in operation for many years to come.
> 
> Thanks in advance,
> 
> Carlos Murillo.

Re: Replacement for a DEC 7474 Chip

[John Robertson via cctalk]

On 2022/05/14 10:11 a.m., Rob Jarratt via cctalk wrote:

Hello,

I have found a bad DEC 7474 chip on my M7133 board. Clearly it is a
7474 D flip flop. The problem is I don't know which modern series
would be the best one to replace it with. I am sure I have seen a list
somewhere of modern equivalents for some DEC chip numbers, but I can't
remember where.

If it helps at all, on the PDP 11/24 printset it is E78 on page K6 of the
schematic (p157 of the PDF).

Picture of the failed chip here:
https://rjarratt.files.wordpress.com/2022/05/damaged-dec-7474-4_li.jpg

Can anyone tell me what the best modern equivalent is likely to be?

Thanks

Rob

You are stuck with using an original 7474 family assuming this is 
driving other early TTL. 74LS74, and others simply don't have the drive 
capability to work. You can use 74S74 or 74F74 as they have the same 
output current, the "S" is Schottky, and the other is "F"aster.


I find that https:///unicornelectronics.com is a reliable source of TTL.

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

Re: Different font for second 1 on commodore 1571 drives (and others)

[John Robertson via cctalk]

On 2022/05/05 10:26 a.m., Toby Thain via cctalk wrote:

On 2022-05-05 1:03 p.m., John Herron via cctalk wrote:
Someone at work pointed this out and I've never really thought about 
it. Is
anyone here aware of the decision or reason to use a different 1 
character

for the last 1 vs the first 1?


Got a picture?


They may have run out of that original font if they were setting the 
type with something like Lettraset in the day.


I restore and sell the first coin operated video game - Nutting's 
Computer Space - and they mixed all sorts of fonts on the control panel. 
It was a pain to reproduce it!


John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

Re: cleaning up edge connectors

[John Robertson via cctalk]

On 2022/04/30 4:28 p.m., dwight via cctalk wrote:

Yep. I didn't know it was now made by someone else. Also look at McMaster-Carr. 
You might get a better price.
Dwight


I've used Dow Corning #4 electrical grease for a couple of decades. It 
really helps preventing corrosion and reduces heating of contacts. You 
can also get it from Aklands Grainger.


John :-#)#




From: Ali 
Sent: Saturday, April 30, 2022 3:23 PM
To: 'dwight' ; 'General Discussion: On-Topic and Off-Topic 
Posts' 
Subject: RE: cleaning up edge connectors


Once the corrosion is removed I recommend using DC-4 on the
connections. It will protect the surfaces and keep great electrical
connections. It is a silicon grease that is non-conductive but keeps
the surface clean and improves metal to metal electrical contact. It
doesn't allow oxides to build at the contact surfaces.
It has measurable improvements of even gold on gold. I've used it on
solder to solder as well other dissimilar metals with good results.
I've used it on high current connections to reduce resistive heating up
to 1000 amperes.


Dwight,

Is this what you are talking about:

https://www.aircraftspruce.com/catalog/cspages/dc4.php

-Ali

Re: Looking for old OAK keyboard/control switch...

[John Robertson via cctalk]

Link to image of switch:

https://www.flippers.com/images/Misc/OAK_Pushbutton_Switch-1973.jpg

Thanks,

John :-#)#

On 2022/04/29 2:14 p.m., John Robertson via cctalk wrote:
I've been hunting for a few years for these switches and was thinking 
that perhaps folks here may have seen them or even have some they wish 
to part with...I've hit all the surplus sites, and poured over old 
copies of old Radio Master Parts Catalogue/Encyclopedias - have 7 of 
those, from 1971 going back to 1942 (have visited bitsavers too of 
course)...


This has a total length of 1-5/8", the actuator bar is 5/8 x 3/16 x 
~1/32", the body is 1/2 x 1/2 x 7/8". This uses spring steel snap-on 
clips to secure it in the rectangular hole in the control/keyboard panel.


They have four pins, two are NC and two are NO, no interconnection 
between the pins.


See attached 15kb photo. Hope this doesn't break the system!

Looking for as many as anyone can spare! These are for restoration 
work, so the more the merrier.


Thanks!

John :-#)#



--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

Looking for old OAK keyboard/control switch...

[John Robertson via cctalk]

I've been hunting for a few years for these switches and was thinking 
that perhaps folks here may have seen them or even have some they wish 
to part with...I've hit all the surplus sites, and poured over old 
copies of old Radio Master Parts Catalogue/Encyclopedias - have 7 of 
those, from 1971 going back to 1942 (have visited bitsavers too of 
course)...


This has a total length of 1-5/8", the actuator bar is 5/8 x 3/16 x 
~1/32", the body is 1/2 x 1/2 x 7/8". This uses spring steel snap-on 
clips to secure it in the rectangular hole in the control/keyboard panel.


They have four pins, two are NC and two are NO, no interconnection 
between the pins.


See attached 15kb photo. Hope this doesn't break the system!

Looking for as many as anyone can spare! These are for restoration work, 
so the more the merrier.


Thanks!

John :-#)#

--
 John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
 flippers.com
 "Old pinballers never die, they just flip out"

Re: Power Supply capacitor physical size

[John Robertson]

On 09/03/2016 10:07 AM, Adrian Graham wrote:

On 03/09/2016 17:39, "Jon Elson"  wrote:


On 09/03/2016 10:56 AM, Noel Chiappa wrote:

From: Jon Elson

needs new caps since one of the 1000uF 16V ones has bulged badly.
...
If I go up to 25V I can get 16mm diameter which is the size of the old
ones.

Capacitors that are subjected to high AC ripple current may need the
large surface area for cooling.

Interesting point - but in his particular case, he should be OK replacing the
old 16V cap with a similar-sized modern 25V cap?



Similar size - then no problem!  But, some new cap types are
VASTLY smaller than the caps from 40 years ago.

Hence my question, I'll stick with the same size but higher voltage.

Cheers!



You do have to consider where in the circuit the capacitor is. If this 
is a switching power supply (as I suspect) then if the cap is after the 
switching transformer it MUST be a low ESR, high temp cap - otherwise it 
won't last very long. If this is on the primary side and is simply 
filtering the input rectified AC then ESR is not as big a problem, but 
you need a good physical size if the switching supply puts out a fair 
bit of current due to heating effects of low frequency ripple.


So, it all depends.

For general repair I would get the best grade of capacitor - say 
Panasonic - with a nice low ESR and away you go.


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: UNIBUS M9312 ROMS

[John Robertson]

On 06/08/2016 3:46 PM, Jay West wrote:

I wrote...
On Thu, Jun 9, 2016 at 6:34 AM, Jay West  wrote:

23-E39A9 is still lost to time, afaik. TMSCP - TU81

To which mike replied...

Could that not be reverse-engineered from the boot code in e.g. Emulex
UC17 ROMs? They could do TMSCP...

BTW what PROM blower would folks recommend for creating/imaging M9312 ROMs?

Possibly, but some (me) are sticklers for original code. Plus, I am not sure, 
but I think someone said this rom did something really bizarre to fit in the 
available rom space - self modifying code or something...

Data I/O 29B

J





No way the M9312 can self modify, it is a burn once PROM - 
82S137/Am27S32/74S573 (1024x4-TS) and can easily be read and blown on a 
Data I/O 29B.


If you have a good copy of the original code it WILL replicate on a new 
PROM just fine.


Reference page of the files:

http://www.bluefeathertech.com/technoid/promfiles.html

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: HP Draftmaster II 7596A: EPROM dumps needed, urgent :-(

[John Robertson]

On 05/21/2016 10:53 PM, David Collins wrote:

Martin, I might be able to help you as I think we have a 7596A.

Are these EPROMs from the processor PCA?  Are you able to tell me which 'U'
numbers they are in the PC board?

I haven't looked at the plotter itself, but the service manual we have shows
the following part numbers for the processor PCA

07595-18039
07595-18040
07595-18041
07595-18042

So I'm not sure if my manual is old and the plotters at that time had 4
EPROMs and yours is newer and has 2? Or are they on another PCA somewhere?

Let me know.

If the plotter we have is in the main museum facility I can possibly help
you, I will check.

David Collins
Curator
HP Computer Museum.


If your version has four EPROMs and the later (otherwise identical) 
machine only used two then chances are the four earlier EPROMs were 
simply combined into two later ones. For example, if the original EPROMs 
were 2708s then two of those would fit into a single 2716. The 2716 was 
easier to program as well being only a single voltage device.


Combining the images is easy as well. The first 2708 image goes from 
000h to 3FFh and the second would go from 400h to 7FFh, as a 2716 holds 
000h to 7FFh worth of data vs. 000h to 3FFh for the older 2708.


Of course this would also work for 2716s into 2732s, etc. just the data 
boundaries change to reflect the device size.


John :-#)#

-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Martin
Peters
Sent: Sunday, 22 May 2016 7:21 AM
To: cctalk@classiccmp.org
Subject: HP Draftmaster II 7596A: EPROM dumps needed, urgent :-(

Hello,

the EPROMs are labeled 07595-18045 and 07595-18046.

Can anyone do a dump for me? It's really urgent. Our local hackerspace wants
to get rid of it, if there is no chance to get the Firmware again.

greetings,
Martin





--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: center tapped power transformer help needed

[John Robertson]

On 05/03/2016 8:51 PM, Jim Brain wrote:

On 5/3/2016 10:48 PM, Chuck Guzis wrote:

On 05/03/2016 08:08 PM, Jim Brain wrote:
60 Hz?  Maybe you could give the guys at Prem Magnetics a call. They're
always sending emails offering to do custom work.

http://www.premmagnetics.com/

Yep, 50/60Hz.  I will check them out.

Also, Ian, thanks for the link.  I'll check them out as well.  I will 
admit, though, those Xformers looks huge in the brochure, and I always 
thought those little 120->6.3V 6VA transformers I used to find in 
cannibalized tape recorders and such were so much smaller.


Jim


Nothing stopping you from using two smaller transformers - 120 primary 
to some secondary voltage, say 24VAC, then a second transformer with a 
240V CT primary that also has a 24VAC secondary. Assuming you get the VA 
figured out correctly these should work and be much smaller than a 
single 240CT to 120VAC transformer.


Hammond Manufacturing makes a wide range of superior quality 
transformers that is widely used by the tube and regular electronics folk.


https://www.hammfg.com/electronics/transformers/power/186-187

I think you will find this series helpful, note the VA rating and get 
yourself one of the 187C20 and a 186C20 - or for a bit extra power and 
to allow for losses, get the 187D20 and 186D20 - wire the 24VAC 
secondaries together (ignoring the centre tap on the secondaries of 
course). Farily compact.


Hammond also will wind you a single or a thousand transformers...I like 
looking at their complete line, including a replacement transformer for 
the early 1920s RCA Radiola III battery radio.


https://www.hammfg.com/electronics/transformers/classic/118944

Amazing range!

https://www.hammfg.com/electronics/transformers/classic/zone

John :-#)#


--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Z80 /WAIT signal question

[John Robertson]

I do know that the Wait signal was used by the Fluke 90 tester so it could be 
clamped on top of an in circuit Z80 and run memory and I/O tests while the CPU 
was doing its regular operations.

On vacation so haven't easy access to the operators manual for the Fluke 90 
though...

John :-#)#

> On Apr 21, 2016, at 1:36 PM, Eric Smith  wrote:
> 
> A friend building a Z80 system asked me about whether the Z80 /WAIT
> signal has any effect during machine cycles that aren't
> memory/IO/intack cycles (i.e., neither /MREQ and /IORQ asserted). The
> user manual only describes the use of /WAIT for adding wait states, so
> I expect it probably only affects mem/IO/intack cycles, but I can't
> find anything definitive in the user manual.
> 
> I'm hoping someone can save me the time of hooking up a logic analyzer
> and running the experiment.
> 
> Thanks!
> Eric

Re: Fan bearing lubricant was Re: WD-40 (again)

[John Robertson]

On 04/17/2016 8:11 PM, Brent Hilpert wrote:

On 2016-Apr-17, at 7:28 PM, Noel Chiappa wrote:


Nope, the cylindrical (outer part of the) bearing is a plain cylinder. But
looking at it closely, it's probably not copper, so it might be that Oilite
stuff.

Online images do give a fair idea of the appearance of the surface texture and 
colour of oilite / porous bronze bearings.
It can generally be readily distinguished from 'pure solid' metal.
e.g.:

http://www.google.ca/search?q=oilite=safari=en=ivns=lnms=isch=X=0ahUKEwjjvbLXkZfMAhULxmMKHUQVDvwQ_AUIBQ

I've removed such bearing fittings often enough from equipment for random stock 
but don't recall whether or not I've seen them in box/muffin fans.

I'd guess that grease may be a poor idea for oilite at least inasmuch as once 
there is grease in the pores the material will probably never again function 
the way it was supposed to with oil.


I use a drop of synthetic motor oil on stuck fans, and tiny motors 
(P{hilips CDM series players) - works very well, no returns in ten years!


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Servicing DEC-T11 based products with a Fluke pod?

[John Robertson]

On 04/15/2016 12:22 PM, John Wallace wrote:

Hi John,

In the apparent absence of other T11-related suggestions, are you aware that 
there are a couple of T11-related manuals on Bitsavers, at least one of which 
has schematics?

There's the T11 Users Manual, and the T11 Evaluation Module Users Guide:
www.bitsavers.org/pdf/dec/pdp11/t11/

Nothing about Fluke pods, but maybe something more than you have at the moment?

Best of luck
John Wallace

I've been looking at the T11 and I mostly just need to trick a Fluke pod 
into doing most of the T11 control, Address and Data lines so I can 
exercise the RAM and ROM attached to it. I will be experimenting with a 
8086 POD as is has multiplexed Address and Data lines (0 - 15) as well.


Of course there is a T11 adapter for the Arduino CPU test project on 
Github, I am getting that as the T11 test is written for the Atari 
System 2...


https://github.com/prswan/arduino-mega-ict/tree/t11

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: A tale of a chip and a socket

[John Robertson]

On 04/09/2016 5:29 AM, Noel Chiappa wrote:

 > From: Torfinn Ingolfsen

 > Most likely a bad solder joint.

That was my first thought, and so I carefully inspected all the pins, but
they all looked good to me. But I suppose it might have been something that
wasn't visually obvious.

Noel

If you suspect solder try simply reheating the legs of the suspect chip 
to see if that cures it.


It could also be that the chip is drifting out of tolerance and the clip 
you put on it added enough extra capacitance (we're talking picofarads 
here) that it was happy again. The IC socket may add just enough 
capacitance again to help the chip get back into its operation band. Has 
anyone else got a similar board and that particular chip has a very 
small value cap on one or more of its legs?


I see this on my 1970s video game boards from time to time - a board 
from the factory would have an added cap on one chip that isn't shown on 
the schematics or in my meagre collection of service bulletins for that 
game. The job was obviously factory as the connection is as clean as all 
the other connections on the board.


Data books don't talk much about this bypass caps issue either, I 
believe it is part of the 'magic smoke' of TTL logic...


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Voltage regulator with alternate voltage source...

[John Robertson]

On 04/08/2016 8:54 AM, wulfman wrote:

https://www.fairchildsemi.com/datasheets/LM/LM7805.pdf

http://www.ti.com/lit/ds/symlink/lm78l05.pdf ( page 8 gives you the
internals for a low power version )

Nothing in the data sheet saying you cant apply voltage to the output.

As per the low power version circuit diagram i cant see how you can do
any damage to it
I was not able to find an internal diagram for the higher power version but
i am sure its close to the same circuit just larger pass transistors.

I took a new regulator and measured the output pin to ground with my
trusty ohmmeter
on the diode setting and had no reading. If you think about it the
output on the regulator is a pass transistor
and the output to ground will be in effect a diode that will not allow
current to pass from output to ground.


My last comment still stands. i doubt you will cause any ill effects to
your regulator.


I personally have done this to some old arcade boards with no ill effects.


On 4/7/2016 6:08 PM, drlegendre . wrote:

"...if you leave the unregulated rail _unattached_ and put +5
switcher straight onto the regulated +5 rail..."

My error, I read that as "attached".

In any event, just lift both the 7805 IN and OUT pins, and then supply
known-solid +5DC between the OUT and GND pads on the board.

No, you can't feed the IN pin with +5V, for as others have mentioned,
the 7805 has a minimum dropout of 2V or so.

On Thu, Apr 7, 2016 at 4:03 PM, William Donzelli 
wrote:


Per his description, the 7805's input will be open. It will not try to
source any current, as it will have none to give.

I suppose there might be a little leakage.

--
Will

On Thu, Apr 7, 2016 at 4:58 PM, drlegendre .  wrote:

I archive all data sheets I run across and I found this information on 
both TI and Fairchild data sheets for the 78H05, LM340 and LM78XX 
devices - it is usually under a heading called Application Hints and for 
some reason Fairchild have removed these Hints from the sheets you quote.


In ALL cases the manufacturers caution that putting voltage to the 
output when the input is not powered CAN DAMAGE THE CHIP.


The sheets I have appear to be a bit hard to find so here are my 
archived copies:


http://www.flippers.com/pdfs/LM340_LM78XX_National_2003.pdf (page 11)

http://www.flippers.com/pdfs/LM78H05A_Fairchild.pdf (page 4)

So, yes, you can get away with it for a short time, but you are 
stressing the regulator outside its design limits and that will shorten 
its life.


John :-#(#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Voltage regulator with alternate voltage source...

[John Robertson]

On 04/07/2016 4:41 PM, William Donzelli wrote:

Does this warning assume that there is something on Vin, and not open?
With a quick look at the internal schematic of an old-school 7805, it
seems like what Bill suggests (leaving Vin open) will not actually do
much.

--
Will
This warning is for someone who is thinking of adding a large filter 
capacitor (>10ufd) on the output of the 78XX device and the manufacturer 
is warning against this. Typically the reason is when the input power 
drops below 2VDC above the ouput (power removed) then the device can 
conduct backwards to ground - if you provide enough current it will 
probably self destruct.


To me it is simple, the manufacturer says don't do it as you will damage 
the device. That is enough for me. If you want to check the internal die 
design you can see why this is so.


John :-#(#

On Thu, Apr 7, 2016 at 7:23 PM, John Robertson <j...@flippers.com> wrote:

On 04/07/2016 2:18 PM, Bill Sudbrink wrote:

drlegendre wrote:

Not saying it's going to smoke-out, but it does
seem like a wonky thing to do.

I disagree about "wonky" let me try with more
diagram and less English:

(+8)
  |
   VIN|ceramic cap
  |-][-
   ___|   |
   | 7805 |--GROUND
      |
  |   |
VOUT|(+5)   |
  |   |
   ___|   |
   | LOAD |---|
   

+8 is not currently available (no pun intended).
I would like to test LOAD without removing 7805
as it is soldered in place.  Is damage to 7805
likely if alternative regulated current is applied
at (+5) and (+8) is left open?

Bill S.




Yes, you can damage the 7805 - READ the data sheets...

Raising the Output Voltage above the Input Voltage:

Since the output of the device does not sink current, forcing

LM340/LM78MXX Series 3-Terminal Positive Regulators LM340/LM78MXX Series
3-Terminal Positive Regulators

the output high can cause damage to internal low current paths in a manner
similar to that just described in the “Short- ing the Regulator Input”
section.


LM340/LM78MXX Series 3-Terminal Positive Regulato John :-#(#

Re: Voltage regulator with alternate voltage source...

[John Robertson]

On 04/07/2016 2:18 PM, Bill Sudbrink wrote:

drlegendre wrote:

Not saying it's going to smoke-out, but it does
seem like a wonky thing to do.

I disagree about "wonky" let me try with more
diagram and less English:

   (+8)
 |
  VIN|ceramic cap
 |-][-
  ___|   |
  | 7805 |--GROUND
     |
 |   |
VOUT|(+5)   |
 |   |
  ___|   |
  | LOAD |---|
  

+8 is not currently available (no pun intended).
I would like to test LOAD without removing 7805
as it is soldered in place.  Is damage to 7805
likely if alternative regulated current is applied
at (+5) and (+8) is left open?

Bill S.




Yes, you can damage the 7805 - READ the data sheets...

Raising the Output Voltage above the Input Voltage:

Since the output of the device does not sink current, forcing

LM340/LM78MXX Series 3-Terminal Positive Regulators LM340/LM78MXX Series 
3-Terminal Positive Regulators


the output high can cause damage to internal low current paths in a 
manner similar to that just described in the “Short- ing the Regulator 
Input” section.



LM340/LM78MXX Series 3-Terminal Positive Regulato John :-#(#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Voltage regulator with alternate voltage source...

[John Robertson]

On 04/07/2016 2:25 PM, geneb wrote:

On Thu, 7 Apr 2016, Bill Sudbrink wrote:


Maybe I'm overthinking this.  If I just put
regulated +5 on the 7805 VIN will it work?


Isn't the minimum input voltage for a 7805, 6vdc?

g.

More like 7VDC input minimum (dropout voltage) for 7805 - there are data 
sheets you know (comment directed at Original Poster).


If the OP wants to put 5VDC in, why not cut out the 7805?

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Voltage regulator with alternate voltage source...

[John Robertson]

On 04/07/2016 2:03 PM, William Donzelli wrote:

Per his description, the 7805's input will be open. It will not try to
source any current, as it will have none to give.

I suppose there might be a little leakage.

--
Will


If his intention is to bypass the 7805 then it should have both input 
and output legs cut and lifted.


John :-#)#

On Thu, Apr 7, 2016 at 4:58 PM, drlegendre .  wrote:

Err.. unless the voltage of the switcher is identical to that of the 7805,
then one device will source current, and the other will sink it.

Like putting two 6V batteries in parallel, where one is fresh and the other
weak. Current will flow until the potentials are equalized. But with two
regulated circuits, I don't see how equality can be achieved.

Not saying it's going to smoke-out, but it does seem like a wonky thing to
do.

On Thu, Apr 7, 2016 at 3:41 PM, wulfman  wrote:


You should be just fine.

On 4/7/2016 1:38 PM, Bill Sudbrink wrote:

If you have a circuit which is normally designed to
operate with an unregulated supply, through a regulator...
say unregulated +8 through a 7805 to a regulated +5 and
you want to test it independent of the +8 supply, if
you leave the unregulated rail unattached and put +5
switcher straight onto the regulated +5 rail, will you
damage the 7805?  Clearly the VIN is open, but the ground
pin will still be attached.  Would this push voltage
back through and screw things up?

Thanks,
Bill S.





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Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Usenet News Servers

[John Robertson]

On 03/06/2016 6:49 AM, Dave G4UGM wrote:

I think Thunderbird will allow import from the old Netscape mail client.

Dave


I access Giganews via Thunderbird (OSX) - works very well...

The downside is it costs about $8/month, but that is a very small 
business expense. Upside is Giganews goes back quite a ways...2003 for 
rec.humour.funny for example.


John :-#)#



-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jerome H.
Fine
Sent: 06 March 2016 14:27
To: General Discussion: On-Topic and Off-Topic Posts

Subject: Re: Usenet News Servers

  >On Saturday, March 5th, 2016 at 12:53:22 +, Robert Jarratt wrote:


My ISP appears to have stopped updating the newsgroups it hosts.

What news servers do people round here recommend?


I have a question about access to newsgroups.  Which currently available
browser is able to access a newsgroups server?  Currently, I am using
Netscape 7.2 under Windows 98SE.  If I upgrade to Windows 10, I probably
won't find anything from Microsoft which will support reasonable access to
newsgroups.  Is there a link to a site which has an application that

supports

access to newsgroups in a manner similar to how Netscape 7.2 provides
access.  BEST would be a browser that also supports access to e-mail in

the

same manner as Netscape 7.2 and which also allows me to copy all of the
archived 100,000 e-mails and posts which I have acquired over the last 15
years.  It is only about 300 MB, so the size is not a factor.

I know someone will probably recall the same question a while ago, but the
answer given then was not sufficient to make the switch.  At least a link

to

the site which has the files to be downloaded would be needed since just
the name of the application does not seem to help me.




-

When I registered 8 years ago, I received the following reply copied

below.

There is no charge for the service.  I have found that about 99% of the

posts

which appear at eternal-september also appear at sunsite.  Mainly, I use
sunsite to check that I am receiving all the posts which have been made to
other servers in addition to having a second source just in case one of

the

servers has crashed or disappears.

The e-mail to sign up was sent to:
news-sig...@sunsite.dk

The other e-mail address that I used to inquire about an acceptable
newsgroup which was not yet carried (alt.sys.pdp11 -  but is now) was:
st...@sunsite.dk

The information should be sufficient to inquire and register.

Note that retention is short for some newsgroups, probably only a few days
while for others the retention can be over a year.  So checking the posts

on

at least a daily basis is recommended until you determine the retention
period.




--

Dear "e-mail address"

You have been registered at the dotsrc.org usenet server.

To be able to read and post articles, you will have to tell your news

client,

that it must perform authentication.

If you forget your username/password, then just register again.

There is no need to remove your registration - your registration will be
removed when it has not been used for 3 months.

More information can be found at:

   http://dotsrc.org/usenet/

Your username is: "e-mail address"
Your password is: "six character password"
Your newsserver is: news.sunsite.dk

IMPORTANT: October 15th 2005 a new access policy was introduced, in order
to make the main focus of the usenet service consistent with our remaining
policy and focus. For further info please see
http://dotsrc.org/usenet/accesschange/

Please remark, that the username and password is for your personal usage
only!

Upon any abuse, your account will be terminated immediately.

Best regards,
Dotsrc.org News Administrator
st...@dotsrc.org

Re: Old MOS Mask-Programmed ROM forgetfulness?

[John Robertson]

On 02/16/2016 12:43 PM, dwight wrote:

It is interesting, I have 1702As that were programmed in 1973 sometime
and they still have their data ( used on my SIM4-01 ).
And yes, I have them backed up.
It is interesting that Data I/O has added supply current
checks. I've used many home made pin adapters over the
years to read old ROMs, as John probably knows, as some
were from pin ball machines.
Some of the earlier ROM also had address latches built in,
making reading tough.
Anyway, making pin adapters is not that hard. I usually stack
a three solder pin, machine pin sockets.
In place I don't want any connection, like Vpp, I pop the pin
out. In other places where I need to rewire, I break the
solder pin off and file it down a little so it won't short.
I do connections and sometimes vector side boards with
soldered wire wrap wire. Often I need switches or sometimes
logic off to the side.
It only takes 15 or so minute to put a typical adapter
together.
Dwight


And one could use a 9-Volt battery for the -9 on one of these home-made 
adapters...


John :-#)#

Re: Old MOS Mask-Programmed ROM forgetfulness?

[John Robertson]

On 02/15/2016 11:25 PM, Eric Smith wrote:

On Mon, Feb 15, 2016 at 11:31 PM, John Robertson <j...@flippers.com> wrote:

Rick, if you want to archive these PROMs (highly recommended) you should be
able to find a Data I/O 29B and get one of the programming packs that
supports NS chips. I may have such a combination in my collection, but that
PROM is not listed in my DATA I/O library of readable parts.

They're not PROMs, they are masked ROMs, and there is *NO* equivalent
PROM, so it's unlikely that there's any support for reading them on
any PROM programmer.


Part of the
problem with the early PROMs is they needed a Sync or Clock signal to be
able to be read.

The MM4221/5221 is fully static, so it doesn't have that particular problem.

It's PMOS, and needs +5V and -12V supplies. The outputs are
TTL-compatible, but the inputs technically are not, due to Vih min of
3.0V. Could be driven by TTL with a pullup resistor, or by CMOS.


Does it share the same pinout as the 1702 MOS Eprom? I can read and 
program those EPROMs in my shop. The 1705 has a Vcc of +5, and a Vdd of 
-9 to a  maximum of -20VDC, it is a 24 pin device though.


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Old MOS Mask-Programmed ROM forgetfulness?

[John Robertson]

On 02/15/2016 10:25 AM, Rick Bensene wrote:

Hi, all,

I have a question about old Mask-Programmed ROMs

The part in question is the National Semiconductor MM5231.  This part is
a 2K-bit PMOS Mask-Programmed ROM, generally organized as 256x8, but
also can be organized (via a MODE pin)as 512x4 bits.  In this particular
application, the parts are used as 256x8.

I'm wondering if anyone knows if these particular ROMs (from the '72
timeframe) have a tendency for bit rot over the years?

I know some of the early MOS ROMs had issues with metallization creep
that would cause data loss/corruption.

I have an old calculator that uses these ROMs as the micro and macrocode
stores.

The machine is catatonic, though the power supplies, master clock
oscillator and divider circuitry, and the other obvious stuff are  OK.
I suspect it is probably stuck in some kind of microcode loop, just
cycling around doing nothing.  I have not yet put  logic analyzer on the
microcode latches yet, but that's probably my next experiment.

Sadly, if one or more of these ROMs (there are 18 of them!) has failed,
it likely means that the machine can't be restored to operation, as this
is quite a rare machine, and there just aren't many of them left around.
I have three different EPROM programmers, but sadly, none of them have
the capability to read these parts.   I was I had a Data I/O programmer,
but alas, haven't come across one with all the Unipak modules I'd need
at a price I can afford.

Thanks,
-Rick
---
Rick Bensene
The Old Calculator Museum
http://oldcalculatormuseum.com




Rick, if you want to archive these PROMs (highly recommended) you should 
be able to find a Data I/O 29B and get one of the programming packs that 
supports NS chips. I may have such a combination in my collection, but 
that PROM is not listed in my DATA I/O library of readable parts. Part 
of the problem with the early PROMs is they needed a Sync or Clock 
signal to be able to be read.


If I think of it tomorrow I will go through my sets, but the best place 
right now is for you to post this request on the Data I/O mail list on 
Yahoo"Data_IO_EPROM" and see if someone there can give you better 
advice.


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Stuck bits on 11/73 Clearpoint 4MB memory - how to repair?

[John Robertson]

On 02/12/2016 6:55 PM, Jay Jaeger wrote:

On 2/12/2016 5:32 PM, Jacob Ritorto wrote:

Hi,
 Seems I have bits 4 and 3 sticking on my Clearpoint QRAM-2-SAB-1 88b
4MB memory in my pdp11/73.

 Can anyone offer hints as to how to identify which component is broken
and how to go about repairing this?

 It's the only memory board in this machine, so I guess the problem
might actually be a bus or processor board, right?  I have no other q-bus
memory to test with, so can't do swapping / process of elimination to be
sure.

 Here's the manual:
http://www.arclightindustries.com/docs/Clearpoint-88B.pdf (which I probably
should add to manx or archive.org or something).

 Here's a snippet of the VMJA diags run illustrating bits 4 and 3
sticking.  During the next VMJA run, all addresses were showing up as
errored instead of just the ones ending in xxx000xx, so I guess it's
getting worse!

@173000g

   Starting system
BOOTING UP XXDP-XM EXTENDED MONITOR

XXDP-XM EXTENDED MONITOR - XXDP V2.5
REVISION: F0
BOOTED FROM DL0
124KW OF MEMORY
NON-UNIBUS SYSTEM

RESTART ADDRESS: 152000
TYPE "H" FOR HELP !

.R VMJA??
VMJAB0.BIC

  CVMJAB0  ECC/PARITY MEMORY DIAGNOSTIC
11/83 CACHE AVAILABLE
SWR = 00  NEW = 40


CSR MAP

CSR 0 1 2 3 4 5 6 7 8 9 A B C D E F
MEMTYPE P


CSR NUMBER 0 CONTROLS TOO MANY BANKS
   2044K OF Q-BUS PARITY MEMORY
   2044K WORDS OF MEMORY TOTAL

 MEMORY CONFIGURATION MAP
  16K WORD BANKS
 1   2   3   4   5   6   7
 012345670123456701234567012345670123456701234567012345670123
ERRORS
MEMTYPE 
CSR 
PROTECT PP
 1   1   1   1   1   1   1
 0   1   2   3   4   5   6
 456701234567012345670123456701234567012345670123456701234567
ERRORS
MEMTYPE 
CSR 
PROTECT
 1
 7
 01234567
ERRORS
MEMTYPE 
CSR 
PROTECT
MEMORY DATA ERROR
   PCBANK  VADD PADD GOOD BAD XOR  CSR  MTYP INT PAT

027606   10  06  0100  10  30  20  0 P   27
027606   10  060002  0102  10  30  20  0 P   27
027606   10  060004  0104  10  30  20  0 P   27
027606   10  060006  0106  10  30  20  0 P   27
027606   10  060010  0110  10  30  20  0 P   27

<< SNIP >>

Well clearly it is only affecting certain address bits - or the
diagnostic would not run at all - note that it is starting at 01000,
  so that points to the memory, rather than the processor or bus, at
least as a first approximation.  No guarantees, but I'd sure start with
that as a working theory.

Another sign: this is right at the boundary between two rows.

If you can't find a schematic, you can use the address to identify the
address lines on the bus (See Table 3, page 1-5), and trace them on the
board to find the relevant row of chips.  Then use the bits the same way
to identify the specific chips.

If the chips are in sockets, you could always pull them one at a time to
find the relevant place in the array, as well.
...

Are you seeing the parity error light when this occurs?

Anyway, once the relevant chip(s) are identified, if they are in sockets
you can swap them with other bits or the same bits in other rows to
confirm.  Otherwise you get to unsolder the suspects, and put in new ones.

JRJ

An old trick we use for testing soldered in DRAM is to simply jam a 
known-to-be-good DRAM on top of the suspect one (legs bent in to make 
good contact). DRAM normally fail bits high and so putting a good one on 
top causes nothing different to happen if the suspect is good, but if 
the suspect is bad then the top DRAM will drive the output and your RAM 
test will pass.


Of course you wedge the good one on the suspect when the power is off. 
Unless you are in a rush, and willing to possibly kill your test DRAM.


As a side note - there appears to be an error message: "CSR NUMBER 0 
CONTROLS TOO MANY BANKS"  Or is that irrelevant? I know nothing about 
the PDP-11 test messages...


John :-#)#

Re: NiCd battery replacement in vintage computers

[John Robertson]

On 02/06/2016 1:29 PM, Paul Koning wrote:

On Feb 6, 2016, at 4:21 PM, Mark J. Blair  wrote:

Today I discovered that I hadn't replaced the NiCd battery in time in my Amiga 
3000. Pictures:
...
While I begin to figure out how I'd like to perform this repair, I'm curious 
about what others have decided to do in similar circumstances. Many options 
come to mind:

* Solder in the same kind of NiCd pack to keep things original.

I haven't yet done this, but I have a device (Fluke 881AB voltmeter) with dead 
NiCd batteries, and when I get around to replacing them that's what I was 
thinking of.  NiCd batteries are still available.


* Solder in a supercap instead.

That has vastly less capacity, and a very different discharge curve 
(exponential vs. nearly flat).  Depending on the circuit using it, that might 
work slightly (at 10% capacity, maybe) or not really at all.


* Reconfigure the circuit to use a non-rechargeable lithium coin cell in a 
holder instead. I don't think I've seen one of those leak before.

It hasn't happened to me, but have heard of one case of a leaking Li primary 
cell.  Not a coin cell, but a C-sized one: I remember a report of one leaking 
in an automatic parachute opener (AAD), wrecking the parachute.  In fairness, 
that was one left in quite a number of years beyond its expiration date.  
(Before someone asks the obvious: the problem was found during a required 
inspection on the ground.)

paul





If you are running batteries in your machines you need to watch out for 
battery leakage! These are all alkaline batteries so the only way to 
neutralize the leakage is to wash and scrub with a mild acid - white 
vinegar mixed 50/50 with pure water works very well.


Next, depending on the RAM device, it may be possible to use a 
Ferromagnetic device to replace these - they are good for over 100 years 
at 1mHz!


5101, 6116, 6264, and others are available from several suppliers 
(including me). I have no idea what CMOS RAM is used in the Amiga, but 
something needs to be done to protect these machines from 
self-destruction by battery suicide!


Currently I have not seen a replacement for CMOS RAM that use separate 
DI and DO pins such as some users of 5101s, but I am trying to get this 
going...


John :-#(#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: NiCd battery replacement in vintage computers

[John Robertson]

On 02/06/2016 1:29 PM, Paul Koning wrote:

On Feb 6, 2016, at 4:21 PM, Mark J. Blair  wrote:

Today I discovered that I hadn't replaced the NiCd battery in time in my Amiga 
3000. Pictures:
...
While I begin to figure out how I'd like to perform this repair, I'm curious 
about what others have decided to do in similar circumstances. Many options 
come to mind:

* Solder in the same kind of NiCd pack to keep things original.

I haven't yet done this, but I have a device (Fluke 881AB voltmeter) with dead 
NiCd batteries, and when I get around to replacing them that's what I was 
thinking of.  NiCd batteries are still available.


* Solder in a supercap instead.

That has vastly less capacity, and a very different discharge curve 
(exponential vs. nearly flat).  Depending on the circuit using it, that might 
work slightly (at 10% capacity, maybe) or not really at all.


* Reconfigure the circuit to use a non-rechargeable lithium coin cell in a 
holder instead. I don't think I've seen one of those leak before.

It hasn't happened to me, but have heard of one case of a leaking Li primary 
cell.  Not a coin cell, but a C-sized one: I remember a report of one leaking 
in an automatic parachute opener (AAD), wrecking the parachute.  In fairness, 
that was one left in quite a number of years beyond its expiration date.  
(Before someone asks the obvious: the problem was found during a required 
inspection on the ground.)

paul





If you are running batteries in your machines you need to watch out for 
battery leakage! These are all alkaline batteries so the only way to 
neutralize the leakage is to wash and scrub with a mild acid - white 
vinegar mixed 50/50 with pure water works very well.


Next, depending on the RAM device, it may be possible to use a 
Ferromagnetic device to replace these - they are good for over 100 years 
at 1mHz!


5101, 6116, 6264, and others are available from several suppliers 
(including me). I have no idea what CMOS RAM is used in the Amiga, but 
something needs to be done to protect these machines from 
self-destruction by battery suicide!


Currently I have not seen a replacement for CMOS RAM that use separate 
DI and DO pins such as some users of 5101s, but I am trying to get this 
going...


John :-#(#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"


--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Restoring Old Paper Tape

[John Robertson]

On 01/21/2016 6:46 PM, Charles Anthony wrote:

On Thu, Jan 21, 2016 at 6:21 PM, Jason T  wrote:


On Thu, Jan 21, 2016 at 8:04 PM, Charles Anthony
 wrote:

For part 2, personally, I would take movies of the paper tape moving and
doing image analysis to recover that data; this occurs to me because I've
done a fair bit of image recognition software, so this solution may not

be

feasible for all. If you sent me a sample movie, I would make a stab at
writing some data recovery software.

I have heard of those approach and was thinking it may be a solution
in cases where the tape is too fragile (and that's pretty likely
here.)  It would be well beyond my abilities but might make an
interesting project for you or anyone else with the skills.



The general approach would be to have the tape backlit (on a piece of
glass, with a light source and and diffuser underneath ) and  guide block
that the tape slides against so the holes move left-to-right but not up and
down. The camera is set up so that the tape fills the image as much as is
feasible. You start the camera, and slide the tape. Constant speed is not
important, but avoid backing up.

Grab a frame from the movie. Figure out the approximate pixel coordinates
of the data and pin feed holes in the axis moving across the tape (eg, the
1 bit is about 24 pixels from the top of the image, the 2 bit is about 47
pixels from the top, etc).

Process the movie a frame at a time. Grab a column of pixels from the
center of the image from top to bottom. Look at the pixels around where the
pin feed is, decide if they are light or dark. If light, the a character is
centered in the column. If not, move to the next frame. look at the pixels
around where each data bit is, and decide if the are light (punched) or
dark (unpunched). Write out that data. Skip frames until the pin feed
pixels go dark, and then skip frames until it goes light again; that will
be the next character. Repeat.

The pin feed holes greatly simplify the process. This process is quite
analogous to reading multi-track magnetic media with a timing track.

Test on a known tape. Debug. Run over damaged tapes; data recovered.

-- Charles

Would it not be simpler to make an optical reader to handle  this job? 
You need a light source and the correct number of opto transistors to 
read the light from each hole. There is an index built into the tape so 
that is easy to set.


Something like this:

http://hackaday.com/2014/05/02/reading-paper-tapes-from-scratch/

Of course my assumption above is based on tape that is still complete. 
If it has holes or can't be pulled then, yes, photographing and visually 
reading the dot patterns may be necessary, but that sounds rather 
impractical if there are more than a couple of tapes to transcribe.


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Data Recovery Services

[John Robertson]

On 01/20/2016 11:22 AM, JC White wrote:

I need to recover some files from a SCSI drive that failed over a decade ago.  
Are there data recovery services that can determine if the files on the drive 
can be recovered or can actually do such a recovery?  Now that I think about 
it, I recently also had a fairly new Western Digital drive suddenly no longer 
be seen by any Windows PC and I really need many of the files on it.  Can 
anybody here tell me if drive manufacturers offer recovery services? I ask this 
since I saw a post somewhere that Seagate offers some sort of file recovery via 
cloud storage.
As you can tell, I am by no means super-knowledgeable about modern systems 
since I am from the WANG 2200 MVP, WANG PC, and WANG Basic 2C era, and still 
have a few pieces of WANG hardware collecting dust.
I apologize if I am posting this to a group where it is inappropriate.
Thank You,
John

If the drive's PCB turned out to be the problem, could an identical 
drive model act as a donor for a known-to-be-good PCB? Of course this 
would depend on the model of the drive. Perhaps you can share that info 
and experts here may have better ideas.


Then you just need to find the same model...and I just drilled out four 
old SCSI drives the other day to kill the data dead (software company's 
drives). Didn't think to save the PCBs...


This could also be a 'shake & bake' drive that needs a bit of trickery 
to get spinning...


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Data Recovery Services

[John Robertson]

On 01/20/2016 2:00 PM, Mark Linimon wrote:

On Wed, Jan 20, 2016 at 12:35:22PM -0800, John Robertson wrote:

If the drive's PCB turned out to be the problem, could an identical
drive model act as a donor for a known-to-be-good PCB?

I've done this on modern drives.  It is not particularly tricky.

mcl

Yes, I know, it depends on the age of the drive as I suspect early ones 
were possibly tuned to the mechanics of the drive. Nothing made after 
2000 is likely to care much though.


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Building a PC - then & now

[John Robertson]

On 01/13/2016 4:54 PM, Chuck Guzis wrote:

On 01/13/2016 03:27 PM, William Donzelli wrote:


In the old days, the shitty kit TVs would have continuous tuners.


In prewar days, it seems that there more than a couple of offerings. 
Didn't Meissner(they of the "Signal Shifter" VFO) offer a kit TV in 
the 30s/early 40s?  I do remember the continuous tuners, though--two 
bands--and one could even tune Channel 1.


A large number of Heathkit color TVs were built by vets using funding 
from the GI bill.  Those were Heath's good days...


--Chuck




I built one of the Heathkit colour TVs in time to watch the moon 
landings. I was 18 and built in one day (and night) and it worked from 
the first turn on. Lasted over twenty years as the main house set only 
needing service every few years until the picture tube gave out finally.


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Free (pay shipping) Hp DDS-4 40gb tapes (only have two)

[John Robertson]

I have two sealed C5718A tapes that are free to the first person to ask 
for them and pay shipping. I hate to throw out something that may still 
be useful.


Can mail them for $5 (I think) to the USA, or local pickup.

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Floppy recovery

[John Robertson]

On 01/05/2016 1:15 PM, Ali wrote:

Anyone know anything about the custom computer and the custom OS? Nor implying 
anything but Chuck do u have any insights? ;)

Didn't Scotty leave his laptop behind when they were saving the whales?

John ;-#)#

Re: "Bounce buffer" copyright [was Re: flash (or ide) storage for unibus 11?]

[John Robertson]

On 11/28/2015 3:41 PM, Mouse wrote:

Love that term, "bounce buffer" (I wrote a whole package to support
them in a packet switch I did) - I'm officially adopting it, right
now! :-)

Hey - anything that anyone writes is automatically copyrighted.

I realize you...may have been less than entirely serious.  But what you
wrote could easily be taken seriously, especially by someone only
partially inside our culture.  So I'm going to be a minor killjoy here.

Yes, anything written now is automatically copyrighted in most
jursidctions.  But (a) the term "bounce buffer" is small enough and
obvious enough it probably cannot be copyrighted on its own (and is not
infringing when copied in isolation), (b) was quite possibly published
without copyright claim before automatic copyright and is thus in the
public domain now, and (c) is of uncertain authorship anyway.  So...


So first you need permission to use that!

...you actually don't.

/~\ The ASCII Mouse
\ / Ribbon Campaign
  X  Against HTML   mo...@rodents-montreal.org
/ \ Email!   7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B

Further to this discussion on 'automatic' copyright. That only came into 
being in 1989 - prior to that ALL documents had to have either the 
symbol (c) or the word COPYRIGHT as well as the name of the person or 
organization on the document (if a single page) or the front page or the 
index page. This was true for the period prior to 1978, however during 
the period 1978 through 1989 you had up to five years to copyright the 
document, otherwise it passed into public domain.


https://copyright.cornell.edu/resources/publicdomain.cfm

One could trademark an expression 'bounce buffer', however as Mouse 
points out you can't exactly copyright it.


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: PROMs and EPROMs, specifically 2332/2532/2732

[John Robertson]

On 10/25/2015 4:37 PM, Adrian Graham wrote:

On 25/10/2015 17:19, "John Robertson" <j...@flippers.com> wrote:


Hi John and others,

Thanks for that. I removed the diodes and wired 2332 (21) to 2372 (24)
leaving the A11 swap in place, the programmer complained about pin 18
missing. The adapter in front of me is now wired like this:

2332 (18) to 2372 (21)
2332 (20) 2x diodes to 2372 18 (band) and 20 (band)
2332 (20) 2k2 resistor to 2332 (24)
2332 (21) to 2372 (24)

Now I get "reverse insertion" hinting I've wired something upside-down which
isn't the case. I can read 27256 and 2764's no problem so I'm mounting
things the correct way.

Further digging into available eproms that the programmer can read reveals
it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
the same pinout as the 2332. I still get "reverse insertion error" so I'm
guessing my PROMs are toast.

Cheers,


Reverse insertion may just mean you are drawing more current on the /OE
and /CS than expected.

How about this - go back to my original suggestion (no diodes) and this
time add a small resistor to the 2732 pin 18 and Vcc to act as a load.
Try larger resistors if the reader still complains - and try reading
with NO 2332 in the reader (all FFs). Once you can trick the reader into
reading air as highs then try your 2332 again with the working resistor
values for the unused select.

Oh, and what reader are you using? Did you check with the manufacturer
(or archives somewhere - archive.org?) to see if they have a trick for
reading 2532/2332s?

It's an MQP Pinmaster48, a 90s-era programmer. As it happens tonight I got
round to dumping some other EPROMs I had for someone else and one of them
was an SGS2532 which read fine as an MCM2532 so I know the machine works
with that age of chip. All my CBM ones give the same results so I'm assuming
they're dead. Thinking about it there may be some 2532s at work so I can try
burning a PET tester.

I saw the madrigaldesign adapter on Friday but after re-re-remaking the one
I was working on yesterday it was beginning to look a bit rough around the
edges :)

Cheers,


Hi Adrian,

Perhaps one final test for your 2332s is to do a Diode Test on the pins 
relative to the ground pin (pin 12) and Vcc pin (24). These should sow 
either open or something like 0.6 or higher voltage drop across the pins 
- exchange the probes to check both directions.


If your gates all read OK (check between Vcc and GND as well!), then it 
might be that the brand of 2332 you have simply draws more current than 
your programmer likes. What brand is the PROM? Perhaps it is in one of 
our reference book libraries...


If your 2332s are bad, then have you put out a call to see if anyone 
else has archived them already?


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: PROMs and EPROMs, specifically 2332/2532/2732

[John Robertson]

On 10/24/2015 5:56 PM, Adrian Graham wrote:



On 24/10/2015 19:18, "John Robertson" <j...@flippers.com> wrote:


On 10/24/2015 5:43 AM, Adrian Graham wrote:

Hi folks,

PET4032 repair continues with all ROMs, video RAM and dodgy sockets removed
thanks to a hot air gun. Holes cleaned and I have new turned pin sockets for
everything I've removed which I'll be fitting this afternoon.

Since the ROMs came out OK I'm trying to dump them using my Pinmaster48
programmer, being from the 90s it doesn't read 2332/2532 PROMs but it WILL
read a lot of variants of 2732 so I've made an adapter as found thanks to
google and USENET:

2332 pin 18 to 2732 pin 21 (A11)
2332 pin 20 to 2732 pin 18 (Chip enable/Power Down)
2332 pin 21 to 2732 pins 20 and 24 via diodes with banding at the 2332 end
(2332 Vpp)

Wiring checks out and the diodes are aligned correctly so pins 20 and 24
don't interfere with each other, however the pinmaster continually gives me
"continuity error on pin 20"

Have I goofed somewhere?

Cheers,


You just tie pin 21 of the 2332 to Vcc (+5) - Pin 24 of the 2732 - to read.

There are only two modifications needed normally for reading a 2532/2332
in a 2732 socket.

2332

Pin 21 - Vcc (2732 Pin 24)
Pin 18 - A11 (2732 Pin 21)

If your reader coughs up a /OE error then use diodes:

2332

Pin 20 - 2 Diodes, one to 2732 pin 20, the other to 2732 pin 18. Banded
end to these pins, and you will also need a pullup resistor on the
2532/2332 socket pin 20 so /CE (2332/2532) goes high when not selected.
2K2 would do fine. Anything from your junk box between 1K and 4K7 should
work though.

I don't think you will need the diodes though.

John :-#)#

Hi John and others,

Thanks for that. I removed the diodes and wired 2332 (21) to 2372 (24)
leaving the A11 swap in place, the programmer complained about pin 18
missing. The adapter in front of me is now wired like this:

2332 (18) to 2372 (21)
2332 (20) 2x diodes to 2372 18 (band) and 20 (band)
2332 (20) 2k2 resistor to 2332 (24)
2332 (21) to 2372 (24)

Now I get "reverse insertion" hinting I've wired something upside-down which
isn't the case. I can read 27256 and 2764's no problem so I'm mounting
things the correct way.

Further digging into available eproms that the programmer can read reveals
it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
the same pinout as the 2332. I still get "reverse insertion error" so I'm
guessing my PROMs are toast.

Cheers,



Reverse insertion may just mean you are drawing more current on the /OE 
and /CS than expected.


How about this - go back to my original suggestion (no diodes) and this 
time add a small resistor to the 2732 pin 18 and Vcc to act as a load. 
Try larger resistors if the reader still complains - and try reading 
with NO 2332 in the reader (all FFs). Once you can trick the reader into 
reading air as highs then try your 2332 again with the working resistor 
values for the unused select.


Oh, and what reader are you using? Did you check with the manufacturer 
(or archives somewhere - archive.org?) to see if they have a trick for 
reading 2532/2332s?


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: PROMs and EPROMs, specifically 2332/2532/2732

[John Robertson]

On 10/24/2015 5:56 PM, Adrian Graham wrote:



On 24/10/2015 19:18, "John Robertson" <j...@flippers.com> wrote:


On 10/24/2015 5:43 AM, Adrian Graham wrote:

Hi folks,

PET4032 repair continues with all ROMs, video RAM and dodgy sockets removed
thanks to a hot air gun. Holes cleaned and I have new turned pin sockets for
everything I've removed which I'll be fitting this afternoon.

Since the ROMs came out OK I'm trying to dump them using my Pinmaster48
programmer, being from the 90s it doesn't read 2332/2532 PROMs but it WILL
read a lot of variants of 2732 so I've made an adapter as found thanks to
google and USENET:

2332 pin 18 to 2732 pin 21 (A11)
2332 pin 20 to 2732 pin 18 (Chip enable/Power Down)
2332 pin 21 to 2732 pins 20 and 24 via diodes with banding at the 2332 end
(2332 Vpp)

Wiring checks out and the diodes are aligned correctly so pins 20 and 24
don't interfere with each other, however the pinmaster continually gives me
"continuity error on pin 20"

Have I goofed somewhere?

Cheers,


You just tie pin 21 of the 2332 to Vcc (+5) - Pin 24 of the 2732 - to read.

There are only two modifications needed normally for reading a 2532/2332
in a 2732 socket.

2332

Pin 21 - Vcc (2732 Pin 24)
Pin 18 - A11 (2732 Pin 21)

If your reader coughs up a /OE error then use diodes:

2332

Pin 20 - 2 Diodes, one to 2732 pin 20, the other to 2732 pin 18. Banded
end to these pins, and you will also need a pullup resistor on the
2532/2332 socket pin 20 so /CE (2332/2532) goes high when not selected.
2K2 would do fine. Anything from your junk box between 1K and 4K7 should
work though.

I don't think you will need the diodes though.

John :-#)#

Hi John and others,

Thanks for that. I removed the diodes and wired 2332 (21) to 2372 (24)
leaving the A11 swap in place, the programmer complained about pin 18
missing. The adapter in front of me is now wired like this:

2332 (18) to 2372 (21)
2332 (20) 2x diodes to 2372 18 (band) and 20 (band)
2332 (20) 2k2 resistor to 2332 (24)
2332 (21) to 2372 (24)

Now I get "reverse insertion" hinting I've wired something upside-down which
isn't the case. I can read 27256 and 2764's no problem so I'm mounting
things the correct way.

Further digging into available eproms that the programmer can read reveals
it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
the same pinout as the 2332. I still get "reverse insertion error" so I'm
guessing my PROMs are toast.

Cheers,


Oh, and here is what someone did in 2011 to read 2332s:

http://www.madrigaldesign.it/forum/viewtopic.php?t=104

John ;-#)#

Re: PROMs and EPROMs, specifically 2332/2532/2732

[John Robertson]

On 10/24/2015 5:43 AM, Adrian Graham wrote:

Hi folks,

PET4032 repair continues with all ROMs, video RAM and dodgy sockets removed
thanks to a hot air gun. Holes cleaned and I have new turned pin sockets for
everything I've removed which I'll be fitting this afternoon.

Since the ROMs came out OK I'm trying to dump them using my Pinmaster48
programmer, being from the 90s it doesn't read 2332/2532 PROMs but it WILL
read a lot of variants of 2732 so I've made an adapter as found thanks to
google and USENET:

2332 pin 18 to 2732 pin 21 (A11)
2332 pin 20 to 2732 pin 18 (Chip enable/Power Down)
2332 pin 21 to 2732 pins 20 and 24 via diodes with banding at the 2332 end
(2332 Vpp)

Wiring checks out and the diodes are aligned correctly so pins 20 and 24
don't interfere with each other, however the pinmaster continually gives me
"continuity error on pin 20"

Have I goofed somewhere?

Cheers,


You just tie pin 21 of the 2332 to Vcc (+5) - Pin 24 of the 2732 - to read.

There are only two modifications needed normally for reading a 2532/2332 
in a 2732 socket.


2332

Pin 21 - Vcc (2732 Pin 24)
Pin 18 - A11 (2732 Pin 21)

If your reader coughs up a /OE error then use diodes:

2332

Pin 20 - 2 Diodes, one to 2732 pin 20, the other to 2732 pin 18. Banded 
end to these pins, and you will also need a pullup resistor on the 
2532/2332 socket pin 20 so /CE (2332/2532) goes high when not selected. 
2K2 would do fine. Anything from your junk box between 1K and 4K7 should 
work though.


I don't think you will need the diodes though.

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Computers in Election Vigils - take two

[John Robertson]

On 10/09/2015 4:50 AM, Alexandre Souza wrote:

lucky you. In Brazil we use vote machines made by diebold, which are as
weak in security as a carton box. And no independent entity can ressearch
its failures.


After the fiasco about the Deibold machines changing votes during the 
Bush election of 2000, Brazil opted for them?


That says a lot about your government I'm afraid. Not unlike US states 
that use Deibold equipment where there is no paper ballot to confirm the 
results after the voting is closed.


That is not democratic at all!

Canada still uses paper ballots for our federal elections. Our election 
voting stations have scrutineers who are volunteers from the various 
political parties running who watch over the proceedings and can call 
for assistance if something unusual happens.


Our local city election (Vancouver) uses a paper ballot that is read 
electronically, but the ballots exist in paper and can be counted by the 
various party scrutineers if they wish (and it happens in closely fought 
ridings).


Canada has had trouble with fake phone calls directing voters to 
non-existent polling stations in an effort to change the outcome where 
ridings are close (the candidates have almost equal chance of winning). 
This was traced to our current government's political party - and the 
governments' response was to change the way Elections Canada can report 
problems and help people to get out and vote - they made it harder 
sigh.


We shall see what happens on Oct 19 when our federal election happens.

John :-#(#



2015-10-09 8:24 GMT-03:00 Stefan Skoglund (lokal användare) <
a13st...@student.his.se>:


tor 2015-10-08 klockan 16:48 -0700 skrev Chuck Guzis:

On 10/08/2015 01:44 PM, Mattis Lind wrote:

Unfortunately SVT Öppet Arkiv is not available to anyone outside
Sweden, which is a pity. A great source.


If the original poster can provide the link(s) folks may want to use 
other methods to watch streaming video...



This interest for computers and election vigils come from the fact
that I had a email conversation with a person that was involved
when
DEC won the contract to for the election in 1976 in Sweden for SVT.
He was involved in adapting the VT30 system for TV use. Genlock and
stuff.

I found three clips in Öppet Arkiv which I trimmed down heavily.
These shows tend to be quite long anyhow. I hope SVT is not getting
mad now.

https://www.youtube.com/watch?v=qDoFM3hfbic

Interesting.  Anent that, here's a nice article about the use of
computers in a US Presidential election in 1952:

http://www.npr.org/sections/alltechconsidered/2012/10/31/163951263/th
e-night-a-computer-predicted-the-next-president

I wonder if there aren't still some congressional districts where
votes
are counted by hand in the US.

--Chuck


All the votes is still counted by hand.
Both att election evening (by election workers) and afterwards
(multiple times) in the months after election.

The "Valvaka" is the election day TV-program, the computers is included
because people wants an early impression of who will be statsminister
in one week, it's an statistical exercise.

AT election day we have 3 different elections:
local municipality (really its "house" which then elects the cabinett
including "city major")
the same for "län" (country council)
and state (election elects the country's riksdag - "house")

Riksdagen elects statsminister (normally, the situation now is a bit
peculiar.)

The state administration thru its "länsstyrelser" (who is geographical
areas corresponding to "län/region" (country council) it responsible
for counting and tabulating votes (country council election and
riksdagen.)

Re: ESR Meter Recommendations

[John Robertson]

On 09/30/2015 7:14 AM, Jay West wrote:

John wrote

That is an authorized Bob Parker variation of his original Dick Smith ESR meter 
kit. On this side of the pond they were made by Anatek until the owner was 
killed in an accident, then the series (now called the Blue ESR) is made by 
Alltronics and sold by dealers such as I. These all use Bob's licensed code, 
just different box and PCB layouts.

If you want a Blue ESR I sell them on my web site's catalogue section, or you 
can order the EVB from Portugal if you are on the east side of the pond.

I've been selling variations (evolution by intelligent design) of Bob's ESR 
meter kit since 1999!

That is great info, thanks!

Question - I could be mistaken, but I think someone mentioned that these were 
not good for testing caps that had a higher operating voltage. Is that correct? 
My understanding was that the testing method used by this ESR meter was valid 
for most all the large electrolytics...?

J




The only caveat is to discharge the capacitor first before testing. The 
meter does not like anything over 50VDC across the probes...tends to let 
the smoke out.


You can use the Blue ESR meter to check the internal resistance of 
batteries - I suspect one could use that info to build a chart of 
remaining life in a lead acid battery or ni-cad, but I never tried that.


Link for some background info:

http://flippers.com/BlueEsr.html

Sales...

http://www.flippers.com/catalog/product_info.php/blue-meter-p-2

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: ESR Meter Recommendations

[John Robertson]

On 09/30/2015 7:14 AM, Jay West wrote:

John wrote

That is an authorized Bob Parker variation of his original Dick Smith ESR meter 
kit. On this side of the pond they were made by Anatek until the owner was 
killed in an accident, then the series (now called the Blue ESR) is made by 
Alltronics and sold by dealers such as I. These all use Bob's licensed code, 
just different box and PCB layouts.

If you want a Blue ESR I sell them on my web site's catalogue section, or you 
can order the EVB from Portugal if you are on the east side of the pond.

I've been selling variations (evolution by intelligent design) of Bob's ESR 
meter kit since 1999!

That is great info, thanks!

Question - I could be mistaken, but I think someone mentioned that these were 
not good for testing caps that had a higher operating voltage. Is that correct? 
My understanding was that the testing method used by this ESR meter was valid 
for most all the large electrolytics...?

J




As for testing large capacitors, about the highest value that gives 
useful readings is around 10,000ufd. Larger than that and the ESR is too 
close to zero ohms unless the cap is really bad...


One other unmentioned (I keep forgetting to add it to the list) benefit 
to the meter is it does read down to 0.01 ohms which can be handy when 
looking for shorts.


Blue ESR Kit Manual:

https://www.flippers.com/pdfs/BlueESR.pdf

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: ESR Meter Recommendations

[John Robertson]

On 09/29/2015 2:59 PM, Jay West wrote:

This is the one I have used for years.

http://clientes.netvisao.pt/greenpal/evb1.htm

About $88 USD

J




That is an authorized Bob Parker variation of his original Dick Smith 
ESR meter kit. On this side of the pond they were made by Anatek until 
the owner was killed in an accident, then the series (now called the 
Blue ESR) is made by Alltronics and sold by dealers such as I. These all 
use Bob's licensed code, just different box and PCB layouts.


If you want a Blue ESR I sell them on my web site's catalogue section, 
or you can order the EVB from Portugal if you are on the east side of 
the pond.


I've been selling variations (evolution by intelligent design) of Bob's 
ESR meter kit since 1999!


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: 21MX proms (per request)

[John Robertson]

On 09/06/2015 2:00 PM, Alexandre Souza wrote:

Jay, no one is pin compatible, I always make adapters. But at least I make
it work :D

2015-09-06 16:00 GMT-03:00 Jay West :


Alexander wrote...
-
Intersting to note: many times i have used eproms in place of these proms.
Usually, flash parts are faster, so better suited to the task.
-

Loader roms:
You may be able to get by with that on loader roms. I've never found
eproms that were functional & pin compatible. What ones did you use for the
1K variety?

Microcode:
I doubt seriously the eproms would be stable for microcode. HP specs 5ns
speed parts for the microcode; what eproms work and can hit those speeds? I
suspect this is one of those "might seem to work" but is a really bad idea.

J



As Jay points out, it is the access speed required by the device you are 
substituting the EPROM for a ROM/PROM that counts. In some cases the 100 
to 400ns access speed of EPROMs won't matter (clock of under 1mHz for 
400ns 2716s to around 4mHz for 100ns EPROMs), but if you are running 
10mHz or faster reads then I suspect you will have problems unless you 
find faster devices than EPROMs for your substitute ROM/PROM...


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Reading ROMs

[John Robertson]

On 09/03/2015 4:56 AM, Vlad Stamate wrote:

While I was trying to read the ROM in my 9121 for Eric Smith I found
out that my Wellon VP-280 could not do it (it could not recognize it
and only read FF FF FF FF). I could use it however to dump the ROM of
an IBM PS2 that I cannot boot anymore (so it is not entirely useless).

So I am asking what you all use to dump various ROMs from vintage
PCs/peripherals/etc? Is there a good brand out there of E(E)PROM
programmer? Do you roll your own solution with an
Arduino/RaspeberryPi?

Thanks,
Vlad.

Some of the early ROMs had extra voltages and unusual select logic and 
for those you either need to make an adapter or get an ancient Eprom 
programmer to be able to read them.


I use Data I/O 29B with a Unipak for most of my old timers, but have a 
Pro-Log unit for the 1702s as well as an Andromeda programmer/reader. 
The Andromeda is pretty flexible in what it will read - it also reads 
1702s - but for burning I use the 29B or the Pro-Log for the earliest chips.


What is the part number of the device you are trying to read? Vlad, are 
you by any chance close to Vancouver BC and thus able to drop by my shop 
where we could read your device and provide you with the file?


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: Data I/O 29B

[John Robertson]

On 08/21/2015 5:33 PM, Billy Pettit wrote:

I have a small batch of Data I/O EPROM burners.  Trying to test them out and 
ran into a nightmare.  They require a pin family and size parameter.  But in 
none of the documentation is there any mention of what these values are.  There 
are some generic pinouts, which are almost useless because Data I/O changed the 
definition of several pins.

Then the manual says to get your part's timing chart and compare them to 409 
pages of timing charts to find the family type!  Nothing is mentioned anywhere 
on how to calculate size parameter.

There should be a chart or document somewhere that gives the parameters by 
model numbers like 2516, 2764, etc.

Anyone know of a document like this?

Anyone have experience with the model 29AB, Model 19, Model 100 gang 
programmer, etc.

At this point, without better data, these 11 -12 deveces are heading for the 
scrap pile.  This is the poorest documentation I've ever seen on a piece of 
test equipment.

Billy Pettit


There is a good support group for these machine hosted by Alfred Morin 
on yahoo.


To join etc, :

https://groups.yahoo.com/neo/groups/Data_IO_EPROM

Also, I have a bit of Data I/O stuff filed away here (not well sorted 
I'm afraid) from TTL - Tech Tools (mail) List:


FTP site is:ftp://ttl.arcadetech.org/TTL/Test_Equipment


https://pairlist7.pair.net/mailman/listinfo/techtoolslist


John :-#)#

Re: Unidentified chip

[John Robertson]

On 08/04/2015 1:48 PM, dwight wrote:

This all assumes it is a TTL and not an ECL or even
and analog chip, such as an opamp.
Dwight


It might be possible to identify it a bit. Using the Diode Test of your 
basic multi-meter you can probably figure out if there is a ground and 
Vcc pins by comparing the likely candidates (pin 8 for gnd, and 16 for 
Vcc) against other TTL based ICs. If they don't match then chack against 
pins 5 and 12 which are alternate G  Vcc pins on some TTL.


If no joy matching to TTL, then make a log of the various pin voltages 
relative to other pins and see if there is a pattern that emerges. 
Compare to CMOS next, then drag out a 16 pin OP-Amp based IC and see if 
it shows anything similar.


I find that inputs and outputs on TTL do show a difference in voltage 
drops relative to Vcc and G, and also which way you use the probes.


I did a small write-up years ago as a starting point:

http://www.flippers.com/service.html#diode

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
Old pinballers never die, they just flip out

Re: Huge news! MARCH's 501c3

[John Robertson]

On 07/27/2015 7:40 PM, Evan Koblentz wrote:



He did say that they got permission from Sellam (and Erik K.)


Correct. We briefed them both on our plans several months ago and 
they're both on board.


Also, a technicality that I neglected to say earlier: MARCH didn't 
become the Federation; instead the Federation is a new entity, 
legally-speaking.



So they weren't assimilated?

(ducking)

John ;-#)#
(watching too many reruns of STNG lately...)

Re: Chromatics on ebay

[John Robertson]

On 07/23/2015 2:15 PM, William Donzelli wrote:

That's just seller's remorse.

It's obviously up to you, but I'd have strongly considered disputing it with
eBay as a seller refusing to honor the auction results is every bit as
bad (or even worse) than a buyer refusing to honor the auction result.

I agree. Report him.

Basic Ebay auctions are extremely easy to do - any idiot can do it.

He had six days while he could review and make sure everything was OK,
and revise the listing if and error was spotted.

--
Will

I had a buyers remorse back in 2006 where a very rare (only one or two 
on the planet) vintage arcade game we were selling got something like 
$4000 at the close. The buyer (call him B/R) pleaded with me to cancel 
his bid as he said he accidentally typed the wrong amount in.


I agreed to cancel the auction.

The item ended up selling for around $750 to the person who was the 
other bidder (call him O/B) who had bid it up to around $3995. However 
O/B has since spent a fair bit of money at my shop and both participants 
are nice guys.


What was interesting is the buyer (B/R) who backed out, had a garage 
storage unit that he had forgotten about and the owner of the garage 
contacted me after not hearing from B/R for many months sold me the 
classic games at a very good price.


I ended up doing just fine as a result.

My 2 cents.

John :-#)#

Re: PDP 11 gear finally moved

[John Robertson]

Oh, sorry, didn't realize they used switchers for the PDP-11s.

However I was talking with a friend of mine last night about my error, 
and he told me that the switching supplies for the PDP-11s were very 
unreliable back in the day. He often had to troubleshoot the machines 
back then. A common failure was caused by static electric shock to the 
machine would blow the supply. NO carpets allowed!!


John :-#)#

On 07/17/2015 2:19 PM, Jay Jaeger wrote:

U - his PDP-11/34 most certainly does use switching power
regulators.  ;)

On 7/17/2015 4:06 PM, John Robertson wrote:

On 07/17/2015 11:53 AM, Mouse wrote:

I do find this witch-hunt against capacitors to be curious, given how
few I've found to have failed.  I suspect a lot of it comes from
audiophools who think this is the way to fix anything...

Perhaps.  But not all of it, certainly.  I'm currently four for four
fixing dead flatscreens by re-capping their power supplies; I imagine
others have similar experiences.  It's not a huge stretch to imagine
that other power supplies may have similar issues; even if it turns out
to not be the case, there is probably at least a little can't hurt
anything, right? running around.

/~\ The ASCII  Mouse
\ / Ribbon Campaign
   X  Against HTMLmo...@rodents-montreal.org
/ \ Email! 7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B


This is not surprising given the vintages of the machines. Modern
machines using switching power supplies (15kHz+) must have capacitors
with low ESR and high capacity to run properly.

Older linear power supplies ran at 50/60hz and as such the capacitors
had much less ripple current (and low frequency to boot) to deal with
and the engineers typically over designed the values of capacitors to
allow for some degradation. The machines you are playing with cost
fortunes back in the day - they HAD to be reliable as possible.

Modern caps run at or near their rated temperature (105C) last around
1,000 to 5,000 hours. The old linear supplies rarely heated the caps
much over 40C and thus the caps would last decades...I put fans on our
LCD monitors in our games and they last just fine.

No fan? Expect a year or two at most before failure.

John :-#)#

Re: PDP 11 gear finally moved

[John Robertson]

On 07/17/2015 11:53 AM, Mouse wrote:

I do find this witch-hunt against capacitors to be curious, given how
few I've found to have failed.  I suspect a lot of it comes from
audiophools who think this is the way to fix anything...

Perhaps.  But not all of it, certainly.  I'm currently four for four
fixing dead flatscreens by re-capping their power supplies; I imagine
others have similar experiences.  It's not a huge stretch to imagine
that other power supplies may have similar issues; even if it turns out
to not be the case, there is probably at least a little can't hurt
anything, right? running around.

/~\ The ASCII Mouse
\ / Ribbon Campaign
  X  Against HTML   mo...@rodents-montreal.org
/ \ Email!   7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B



This is not surprising given the vintages of the machines. Modern 
machines using switching power supplies (15kHz+) must have capacitors 
with low ESR and high capacity to run properly.


Older linear power supplies ran at 50/60hz and as such the capacitors 
had much less ripple current (and low frequency to boot) to deal with 
and the engineers typically over designed the values of capacitors to 
allow for some degradation. The machines you are playing with cost 
fortunes back in the day - they HAD to be reliable as possible.


Modern caps run at or near their rated temperature (105C) last around 
1,000 to 5,000 hours. The old linear supplies rarely heated the caps 
much over 40C and thus the caps would last decades...I put fans on our 
LCD monitors in our games and they last just fine.


No fan? Expect a year or two at most before failure.

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
Old pinballers never die, they just flip out

Re: email gripe

[John Robertson]

On 07/07/2015 4:44 PM, Chris Osborn wrote:

On Jul 7, 2015, at 4:18 PM, Chuck Guzis ccl...@sydex.com wrote:


using Thunderbird

Which I’ve noticed has problems parsing the

General Discussion: On-Topic and Off-Topic Posts 
cctalk@classiccmp.org

No matter which platform anyone is using, it’s always Thunderbird that creates 
the gene...@classiccmp.org address into the To: field.

Not sure what you are talking about - my Thunderbird (OSX 31.7.0) when I 
hit reply (Apple-R) created the To: field as: General Discussion: 
On-Topic and Off-Topic Posts cctalk@classiccmp.org.


Am I missing something here?

John :-#)#
(mostly lurking from Vancouver, BC)

Re: Reading/Verifying the Intel 8041A

[John Robertson]

On 05/20/2015 7:15 PM, Richard B. Main, Esq. wrote:

The Intel AFN-00188B Datasheets for 8041A/8741A specify that EA max is
24.5V. The verify mode for PROM/ROM holds EA high at 23V.

The 8048/8748 Datasheets say EA is 32V for 8748 Verify but need only be
+12V for 8048.

Richard

Speaking of old textbooks, something people need to keep an eye out for 
are old parts catalogues put out by the large parts distributors of yore.


I have an Electrosonic Catalogues (Canada - 600 some pages of 
components!) from the late 60s and it is great because they have 
unarchived specifications on many of the early solid state and EM parts 
- many of which are used in older computers. One spec sheet I found was 
a comparison sheet of CDS cells that were common in 1969 and gave their 
range of specs - handy!


The advantage for me is I use these to get the specs on old parts that I 
am trying to repair, or replace with more modern parts. At one time 
E-Sonic had a few PDFs of these early manuals online, but they seem to 
have hidden them since the last time I visited their site. And I just 
did a bit of a search using Archive.org's wayback machine and can't find 
the year when they did have those on their site...


John :-#)#