Re: 1/2 tape in Bell ESS5

[Pete Lancashire via cctalk]

That was suppose to be 1ESS NOT a 5

On Sun, Jul 30, 2017 at 11:53 AM, Pete Lancashire 
wrote:

> Anyone know the spec s for the tape drives in a ESS5 exchange ?
>

Re: 1/2 tape in Bell ESS5

[Pete Lancashire via cctalk]

I got things totally mixed up, The email to the CC list was suppose to be
1ESS and other one to a different list was suppose to be 5ESS



On Sun, Jul 30, 2017 at 2:00 PM, Al Kossow via cctalk  wrote:

>
> http://www.tape-replacement.com/support/lucent-at-t-5ess/
>
> I've seen M4 Data 9914V drives configured for 48v and At part numbers
>
> https://en.wikipedia.org/wiki/5ESS_Switching_System
>
> On 7/30/17 11:53 AM, Pete Lancashire via cctalk wrote:
> > Anyone know the spec s for the tape drives in a ESS5 exchange ?
> >
>
>
>

PDP-11: DR11-C to FPGA or 1284?

[Fritz Mueller via cctalk]

So, I have lately been using PDP11GUI to retrieve images of RK05 disk packs and 
to write images to these packs on a PDP-11.  This is awesome, but its a bit 
frustrating that it takes a couple hours to read or write an image this way.

I do, however, have a couple of DR11-C parallel interface cards.  It occurred 
to me that it might be pretty straightforward to interface one of these to an 
FPGA eval card, and this would give me a much higher-bandwidth way to move data 
on and off the PDP-11 (in fact, the RK11 could even be run in 
non-increment-address-mode pointed at the DR11-C, which would be pretty speedy.)

Another approach might be to interface the DR11 directly to a 1284-to-USB 
adapter.  This would only be eight bits wide, so you couldn't use the direct 
RK11/DR11 NPR hack, but it would still be a lot faster than 9600 baud serial.

Before I put too much thought into either of these, I thought I'd ping here to 
see if anybody else has already interfaced a DR11 in either of these two ways?

cheers,
  --FritzM.

Re: 1/2 tape in Bell ESS5

[Jon Elson via cctalk]

On 07/30/2017 01:53 PM, Pete Lancashire via cctalk wrote:

Anyone know the spec s for the tape drives in a ESS5 exchange ?

Relabeled CDC Keystone 92181?  I'm pretty sure they did call 
logging on these.  Very likely the Keystone was connected to 
a 3B2 that received the data over some comm format from the 
ESS computer.  The data rate was not real high.
But, there may have been other tape drives for other 
purposes (firmware, diagnostics, etc.)


Jon

Re: Sperry UTS 40 on Ebay - Statesboro, Georgia

[Dominique Carlier via cctalk]

*I still suspect PSU (not food ^^ bad translator)


On 30/07/2017 22:44, Dominique Carlier via cctalk wrote:


Thanks a lot, but as described in my last post, I finally found the 
location of the missing battery. I repast the text here:


Yes ! I found it !


http://zeltrax.com/classiccmp_forum/06.jpg

You are right, there was indeed a beginning of corrosion with a 
leaking battery. I had taken it away, I could not remember it at all.
I still have to find the voltage of this missing battery, do you know 
it? Otherwise I have this UTS20D, there may also be a battery with the 
same value ...


So I cleaned the rest of the acid, no damage I think.

http://zeltrax.com/classiccmp_forum/05.jpg

So it would only be the cause of the blank screen? That would be so 
great !! :-)
I also disassembled the PSU board, some inflated capacitors, I'm going 
to replace all these caps. There is also a broken/burned "molex" 
connector.


I will repair all this and I will post a topic dedicated to the 
restoration of this machine.

Thank you all for the information !


Unfortunately, in the meantime I replaced a series of capacitors at 
the end of life, repaired the broken / burned Molex, built a replica 
of this battery and it does not change anything, I always have a blank 
screen.
I still suspect food, something else that seems strange to me is the 
absence of sound of static electricity when I turn on or off the 
monitor, the filaments of the CRT collar nevertheless.

Difficult without schematics



On 30/07/2017 22:26, jim stephens via cctalk wrote:



On 7/30/2017 4:43 AM, Dominique Carlier via cctalk wrote:

Can you tell me where the batteries are supposed to be, on which board?
I disassembled the machine, extracted the 4 motherboards, I did not 
see any batteries anywhere.
If they are externalized, maybe I removed them a long time ago in 
the idea of replacing them, but I have not yet found where they were 
connected in that case.


I don't know there are batteries, but the device had a lot of 
configurations which were retained by some means.  1999 was a bit 
early for eeproms that didn't have battery backup of some sort.


If there are no batteries visible, or large super caps which can back 
up memory content, that is a good thing.


There may also be Dallas modules in the thing or similar which 
integrate batteries.  The components will usually have had a 5 to 10 
year lifespan, and probably won't work so well across power cycles.


thanks
Jim


On 28/07/2017 11:25, jim stephens via cctalk wrote:
I do hope you get it going.  If you feel qualified, one thing I'd 
also look for are packs with batteries to hold information that may 
have decayed.  That sometimes can cause what you described.  since 
the system may have been left since 1999, the batteries may have 
gone onto corrosion and you may have a bit of fixing to do for that.

Re: 1/2 tape in Bell ESS5

[Al Kossow via cctalk]

http://www.tape-replacement.com/support/lucent-at-t-5ess/

I've seen M4 Data 9914V drives configured for 48v and At part numbers

https://en.wikipedia.org/wiki/5ESS_Switching_System

On 7/30/17 11:53 AM, Pete Lancashire via cctalk wrote:
> Anyone know the spec s for the tape drives in a ESS5 exchange ?
> 

Re: Cleaning a board slightly oxydized ??

[Alexandre Souza via cctalk]

Light green? Was it battery electrolyte? Wash it with vinegar (yes,
vinegar) and after, wash with a good detergent and warm water.
I did a video of the washing part, saving a macintosh.
https://www.youtube.com/watch?v=ez5IbF39SRY
(in portuguese, since I'm Brazilian :) But you can watch it and understand
the workings :oD )

2017-07-30 16:25 GMT-03:00 GerardCJAT via cctech :

> What is the best way to clean a ( populated ) board lightly oxydized  ,
> that shows light green copper oxyde spots ( only on the components side ) ??
>
> Toothbrush +  ??
>

Cleaning a board slightly oxydized ??

[GerardCJAT via cctalk]

What is the best way to clean a ( populated ) board lightly oxydized  , that 
shows light green copper oxyde spots ( only on the components side ) ??

Toothbrush +  ??

1/2 tape in Bell ESS5

[Pete Lancashire via cctalk]

Anyone know the spec s for the tape drives in a ESS5 exchange ?

VMS 2691 PSU smoke

[Ian Robert Frost via cctalk]

Hi all

I try and boot up most of the working systems I’ve got at least 2-3 times a 
year, and on a recent boot up of a Cambridge Workstation, I got the dreaded 
smoke.

The system works fine, but the PSU is clearly stressed. The PSU is a ‘VMS 
2691A’, made in the UK, and it looks like the problem is around a large / 
ceramic 22K resistor. There is a fair amount of brown leakage on the PCB too.

Any body any experience in fixing these old Acorn PSUs - or managed to source 
alternative modern supplies?

Thanks

Ian

Re: 8mm cinemax type film players (almost OT)

[Fred Cisin via cctalk]

On Sun, 30 Jul 2017, Paul Koning via cctalk wrote:
On 8 mm types: there's the original 8 mm (later called "double 8" 
because the unexposed film is essentially 16 mm film which is exposed on 
one side, flipped over, and exposed on the other side, then slit in half 
to make 8 mm finished film).


That 16mm film is reporforated - twice as many sprocket holes as "normal 
16mm".  It can be made from 16mm by anybody who has a light-tight 
perforator (not many around)


I think that I know where my developing tanks are, but no idea where my 
splitter is.  THAT is easy to make a replacemnt.


Then there is super 8, which is a 
different format entirely.  Around the time super 8 was introduced, some 
company came out with yet a third format called "single 8". I haven't 
seen that lately, and I don't know anything about how it relates to the 
other two.  If I remember right, it came in a casette with the two 
spools enclosed in a single figure 8 shaped enclosure, for ease in 
handling.


There was a single 8mm that was pre-split before exposure.  That 
disappeared when Kodak dropped it.
There was also a variant super-8 that used a figure 8 cartridge, instead 
of the usual coaxial cartridge.

Re: Cambridge Workstation woes - VMS 2691 PSU smoke

[Jules Richardson via cctalk]

On 07/30/2017 11:28 AM, Tony Duell wrote:

On Sun, Jul 30, 2017 at 5:18 PM, Jules Richardson via cctalk
 wrote:

On 07/30/2017 10:59 AM, Ian Frost via cctalk wrote:


Any body any experience in fixing these old Acorn PSUs - or managed to
source alternative modern supplies?


In general smoke from a power supply that keeps on working is from the
mains filter capacitors. Some makes are well-known for this. I would
carefully examine them, they crack when they fail


Aha, I missed the "kept working" bit... agreed there, then, it's probably 
one of the input caps which failed (and that seems consistent with brown 
goo on the PCB, too).



The former are the ones that normally fail, but I would change the lot.


I'd be inclined to agree in the case of any class X/Y caps as they're a 
known failure point in any piece of vintage equipment... but not every 
single cap in the PSU. I know that's not what you're suggesting, but there 
seems to be a trend amongst collectors to blindly replace every cap in 
sight as part of some "refurbishment process" these days, whether they're 
good or bad. Personally I like to keep my systems as original as possible, 
which generally precludes replacing perfectly-good vintage components with 
perfectly-good modern ones :-)



I certainly traced out the schematics of mine, but I forget which PSU was
fitted to my machine (something tells me it was made by Farnell).


That could well be - I do think that I've seen another type of PSU used in 
addition to the VMS one, and Farnell would be an obvious choice.


cheers

Jules

ATX PSU breakout/adapters - Re: Cambridge Workstation woes - VMS 2691 PSU smoke

[Toby Thain via cctalk]

On 2017-07-30 12:18 PM, Jules Richardson via cctalk wrote:

On 07/30/2017 10:59 AM, Ian Frost via cctalk wrote:

Any body any experience in fixing these old Acorn PSUs - or managed to
source alternative modern supplies?


There wasn't anything "special" about them, in that the outputs were
typical for "small computer with a hard disk" (i.e. +5V and +12V at a
few amps, -5V and possibly -12V, main regulation done on the +5V rail,
"hard start" via physical switch).

I expect it's possible to find a modern PC PSU in some kind of slimline
form-factor which will physically fit (and rig the soft-start so that it
powers up as soon as AC is applied).


FWIW I recently discovered this little PCB which looks darn useful for 
power control + breakout (ignore the RPi part).


https://hackaday.io/project/20963-mini-atx-psu
https://www.tindie.com/products/tomtibbetts/piryte-mini-atx-psu-for-raspberry-pi/


> I expect the current limits for the

different rails are printed on the side of the VMS PSU's frame, so
as-good-or-better should be fine.
...

cheers

Jules

Re: Cambridge Workstation woes - VMS 2691 PSU smoke

[Guy Dawson via cctalk]

The PSUs in the Acorn BBC Micros are we'll know for blowing caps. Replacing
caps is a standard thing when bring any BBC Micro back to life.

The StarDot forum is a good place to ask specifics about a Cambridge
Workstation - http://www.stardot.org.uk/forums/



On 30 July 2017 at 17:28, Tony Duell via cctalk 
wrote:

> On Sun, Jul 30, 2017 at 5:18 PM, Jules Richardson via cctalk
>  wrote:
> > On 07/30/2017 10:59 AM, Ian Frost via cctalk wrote:
> >>
> >> Any body any experience in fixing these old Acorn PSUs - or managed to
> >> source alternative modern supplies?
>
> In general smoke from a power supply that keeps on working is from the
> mains filter capacitors. Some makes are well-known for this. I would
> carefully examine them, they crack when they fail
>
> There will be class X capacitors between live and neutral and class Y
> between
> live and earth and neutral and earth, The former are the ones that
> normally fail,
> but I would change the lot.
>
> > Unfortunately I did trace out some, possibly all, of that PSU (most
> likely,
> > it was certainly a VMS-something in my ACW) years ago, but even if I do
> > still have the schematics, they're on the other side of the Atlantic. The
> > PSU in mine had the rectifier diode on the +12V rail go intermittent,
> so it
> > would start sometimes and not others.
> >
> > Tony D. might have schematics, but I have a feeling they weren't part of
> the
> > ACW service manual as the PSU was bought in from an external supplier and
> > not an Acorn part.
>
> I certainly traced out the schematics of mine, but I forget which PSU was
> fitted to my machine (something tells me it was made by Farnell). I can
> try to find them.
>
> -tony
>



-- 
4.4 > 5.4

Re: Cambridge Workstation woes - VMS 2691 PSU smoke

[Tony Duell via cctalk]

On Sun, Jul 30, 2017 at 5:18 PM, Jules Richardson via cctalk
 wrote:
> On 07/30/2017 10:59 AM, Ian Frost via cctalk wrote:
>>
>> Any body any experience in fixing these old Acorn PSUs - or managed to
>> source alternative modern supplies?

In general smoke from a power supply that keeps on working is from the
mains filter capacitors. Some makes are well-known for this. I would
carefully examine them, they crack when they fail

There will be class X capacitors between live and neutral and class Y between
live and earth and neutral and earth, The former are the ones that
normally fail,
but I would change the lot.

> Unfortunately I did trace out some, possibly all, of that PSU (most likely,
> it was certainly a VMS-something in my ACW) years ago, but even if I do
> still have the schematics, they're on the other side of the Atlantic. The
> PSU in mine had the rectifier diode on the +12V rail go intermittent,  so it
> would start sometimes and not others.
>
> Tony D. might have schematics, but I have a feeling they weren't part of the
> ACW service manual as the PSU was bought in from an external supplier and
> not an Acorn part.

I certainly traced out the schematics of mine, but I forget which PSU was
fitted to my machine (something tells me it was made by Farnell). I can
try to find them.

-tony

Cambridge Workstation woes - VMS 2691 PSU smoke

[Ian Frost via cctalk]

Hi all

I try and boot up most of the working systems I’ve got at least 2-3 times a 
year, and on a recent boot up of a Cambridge Workstation, I got the dreaded 
smoke.

The system works fine, but the PSU is clearly stressed. The PSU is a ‘VMS 
2691A’, made in the UK, and it looks like the problem is around a large / 
ceramic 22K resistor. There is a fair amount of brown leakage on the PCB too.

Any body any experience in fixing these old Acorn PSUs - or managed to source 
alternative modern supplies?

Thanks

Ian

RE: Sperry UTS 40 on Ebay - Statesboro, Georgia

[Rob Jarratt via cctalk]

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Dominique
> Carlier via cctalk
> Sent: 30 July 2017 12:44
> To: jim stephens via cctalk 
> Subject: Re: Sperry UTS 40 on Ebay - Statesboro, Georgia
> 
> Can you tell me where the batteries are supposed to be, on which board?
> I disassembled the machine, extracted the 4 motherboards, I did not see any
> batteries anywhere.
> If they are externalized, maybe I removed them a long time ago in the idea of
> replacing them, but I have not yet found where they were connected in that
> case.
> 
> 


Could it be a Dallas DS1287 like this: 
http://classic-computers.org.nz/blog/2009-10-10-renovating-a-dallas-battery-chip.htm?

Regards

Rob

Re: eBay: RL02 packs, UK

[Aaron Jackson via cctalk]

I think this is the third time he has listed RL02K packs with the same
image. Either the buyer doesn't pay or they just have a huge number of
them. I bought some 8in floppies from the same seller. They are from
Rutherford Appleton Laboratories, so I assume the packs are too.

There is another seller, different name, but same address listed at the
bottom, who is also selling the packs (some new ones too).

Aaron.

Noel Chiappa via cctalk writes:

> Lot of 6; UK only, I think
>
>   http://www.ebay.com/itm/253056726492
>
>   Noel

Re: Sperry UTS 40 on Ebay - Statesboro, Georgia

[Dominique Carlier via cctalk]

Yes ! I found it !

http://zeltrax.com/classiccmp_forum/06.jpg

You are right, there was indeed a beginning of corrosion with a leaking 
battery. I had taken it away, I could not remember it at all.
I still have to find the voltage of this missing battery, do you know 
it? Otherwise I have this UTS20D, there may also be a battery with the 
same value ...


So I cleaned the rest of the acid, no damage I think.

http://zeltrax.com/classiccmp_forum/05.jpg

So it would only be the cause of the blank screen? That would be so 
great !! :-)
I also disassembled the PSU board, some inflated capacitors, I'm going 
to replace all these caps. There is also a broken/burned "molex" connector.


I will repair all this and I will post a topic dedicated to the 
restoration of this machine.

Thank you all for the information !

On 30/07/2017 13:43, Dominique Carlier via cctalk wrote:

Can you tell me where the batteries are supposed to be, on which board?
I disassembled the machine, extracted the 4 motherboards, I did not 
see any batteries anywhere.
If they are externalized, maybe I removed them a long time ago in the 
idea of replacing them, but I have not yet found where they were 
connected in that case.



On 28/07/2017 11:25, jim stephens via cctalk wrote:
I do hope you get it going.  If you feel qualified, one thing I'd 
also look for are packs with batteries to hold information that may 
have decayed.  That sometimes can cause what you described.  since 
the system may have been left since 1999, the batteries may have gone 
onto corrosion and you may have a bit of fixing to do for that.

Convex documentation online (C220 arrived)

[Camiel Vanderhoeven via cctalk]

My Convex C220 arrived about a week ago, so I now have a C1, C1 XL, and a
C220. A C240 will follow in a few weeks. Along with the C220 came some
installation tapes, and a large volume of documentation (some 300
documents). As long as I don¹t receive any objections to the being online
from HP (current owner of Convex), I¹ve put most of the loose-leaf hardware
documentation online at
http://www.vaxbarn.com/index.php/2-uncategorised/609-convex-documentation.
This includes the theory of operation manual, which gives a nice description
of how the big vector processor works.

For those interesting in pictures of the machine and the boards installed,
http://www.vaxbarn.com/index.php/41-acquisitions/608-arrival-of-the-c220

Kind regards,

Camiel Vanderhoeven

Re: Sperry UTS 40 on Ebay - Statesboro, Georgia

[Dominique Carlier via cctalk]

Can you tell me where the batteries are supposed to be, on which board?
I disassembled the machine, extracted the 4 motherboards, I did not see 
any batteries anywhere.
If they are externalized, maybe I removed them a long time ago in the 
idea of replacing them, but I have not yet found where they were 
connected in that case.



On 28/07/2017 11:25, jim stephens via cctalk wrote:
I do hope you get it going.  If you feel qualified, one thing I'd also 
look for are packs with batteries to hold information that may have 
decayed.  That sometimes can cause what you described.  since the 
system may have been left since 1999, the batteries may have gone onto 
corrosion and you may have a bit of fixing to do for that.

Anyone Have a DECstation 220?

[Rob Jarratt via cctalk]

I have gone back to check some tracks in the leak-damaged area and I am
having some difficulty verifying the connections to one of the chips.

 

Does anyone have one of these machines, preferably working, that could help
me to check a few connections?

 

Regards

 

Rob