RE: PDP 11 gear finally moved

[tony duell]

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

True, but I still haven't had major capacitor problems in one.

-tony

RE: PDP 11 gear finally moved

[tony duell]

>
> I had to do some cap replacement on some older Motorola tube radios,I have
> some basic soldering skills. I was under the impression that the capacitors
> in computer equipment this big from this year would have been of better
> quality and it would not be an issue.

In general I will agree with that. Of course a capacitor can fail, but it is 
not that
common. I certainly have never felt the need to 'recap' a classic computer PSU

> I have someone scheduled to come out tonight after i get off work and get
> it out of the rack.

You do not need to remove the complete CPU from the rack. DEC machines of
this vintage were made to be repaired. The CPU (assuming it's the 10.5" high 
box)
will slide out on slide rails, and there are catches to let you turn it so that 
the front panel
points upwards. With the CPU in various positions you can remove just about any 
part
of it without taking it out of the rack. In fact having it in the rack makes 
things easier
in some cases.

Basically, you take the top and bottom covers off, then the top cover of the 
power supply. Tip 
the CPU up, then unplug the cables on the distribution panel under the machine 
(6 pin and 15 pin
connectors). You can now test the PSU on its own. If you have to go further you 
will see that the 
PSU is fixed to the rest of the CPU box by 3 screws each side. If you take out 
the bottom 2 each side
and loosen the top one it will hinge away (the metal is cut to allow this) and 
you can get to the fixing
screws and connectors for the regulator modules. 

If you need to remove the unit under the transformer, you unplug the cables, 
undo 3 or 4 screws, and it
slides out rearwards. 

Of course you unplug the mains cable before working on anything and only plug 
it in when you
need to do some tests. But unlike more modern SMPSUs, there are no lethal 
stored voltages in this
unit.

-tony

RE: PDP 11 gear finally moved

[tony duell]

> Thank you for the detailed information. I need to figure out how im going
> to get it out of the rack and moved to a place where i can test it over the
> next couple days where it will not be in the way.  Ill find some way to do
> a dummy load and do an extended test to be sure the supply is working
> properly. All fingers crossed, god it better not have damaged any of the
> boards, i do not know where i would get replacements.It took years for me

DEC PSUs of that vintage have a crowbar circuit which effectively short-circuits
the PSU (using an SCR) if the voltage rises too high to protect the rest of the 
machine. 

On the other hand if the +5V line did get too high it could have wiped out 
just about every IC in the unit. Ouch!. I've only ever had this happen once, and
it was in a much lesser machine than a PDP11 (fortunately).

> to get the machine, who knows how long it would take to find a specific
> board that is bad. I did buy an oscillicope and a logic analyzer well in

In general you should be thinking of repairing these machines on the component
rather than board level. You may well have difficulty in finding a particular 
board 
(and how do you know that the replacement is good?) but finding one of the logic
ICs is very easy.

> advance in preparation for getting this machine, however short of pressing
> the power button no clue how to use them or basic troubleshooting
> procedures. Guess i just have to learn by doing

That's how quite a few of us (including myself) learnt...

The basic procedure that I use goes like this  :

1) What should the machine be doing? In other words, from the schematics I 
deduce that
there should be a clock signal on 'that wire' or data flowing there with enable 
pulses on that
pin.

2) What is the machine doing (determined by examining said signals with a 
'scope and LA)

3) Why the difference? If they are the same then that part of the machine is 
mostly working
properly. If not, then what could explain what I am seeing, How can I determine 
what the 
cause is? Aha... What is _that_ signal doing? Check it

-tony

Re: MC68451 datasheet wanted

[Chuck Guzis]

On 07/17/2015 04:03 PM, Eric Smith wrote:

Looking for an MC68451 datasheet (or scan). Most of the ones that turn
up from the usual database sites are actually for the MC68450 DMA
controller, which is entirely unrelated. The only one I found that is
actually for the MC68451 was "Advance Information" from a databook,
and did not include the pin grid (R or RC suffix) pinout. There was a
"loose" (not in databook) datasheet that is more recent, labeled
"Preliminary" rather than "Advance Information", and later versions of
that include the pin grid pinout. Does anyone have that?


The DIP version datasheet is also in the 1981 "Motorola Microprocessors 
Data Manual", page 4-818 to 4-835, but no PGA pinout, sorry.


--Chuck

Re: MC68451 datasheet wanted

[Al Kossow]

I have it. I'll postprocess and upload it and email you the pinout page


On 7/17/15 4:03 PM, Eric Smith wrote:

Looking for an MC68451 datasheet (or scan). Most of the ones that turn
up from the usual database sites are actually for the MC68450 DMA
controller, which is entirely unrelated. The only one I found that is
actually for the MC68451 was "Advance Information" from a databook,
and did not include the pin grid (R or RC suffix) pinout. There was a
"loose" (not in databook) datasheet that is more recent, labeled
"Preliminary" rather than "Advance Information", and later versions of
that include the pin grid pinout. Does anyone have that?

MC68451 datasheet wanted

[Eric Smith]

Looking for an MC68451 datasheet (or scan). Most of the ones that turn
up from the usual database sites are actually for the MC68450 DMA
controller, which is entirely unrelated. The only one I found that is
actually for the MC68451 was "Advance Information" from a databook,
and did not include the pin grid (R or RC suffix) pinout. There was a
"loose" (not in databook) datasheet that is more recent, labeled
"Preliminary" rather than "Advance Information", and later versions of
that include the pin grid pinout. Does anyone have that?

docs & sw wanted for Heurikon HK 68/ME-2 and HK 68/M10-3, Micro Memory Inc. MM-9000

[Eric Smith]

I've got one each of the Heurikon HK 68/ME-2 and HK 68/M10-3 multibus
boards. There are brochures on bitsavers, but does anyone have
documentation, schematics, or software for either of these?

It also would be nice to get documentation, or at least switch and
jumper settings, for the Micro Memory Inc. MM-9000 Multibus/iLBX RAM
board. I have the 4MB version, using 144 256K DRAMs (includes parity),
but there was apparently also a 1MB version using 64K DRAMs. Aside
from the DRAMs I expect the difference is in the jumper or switch
settings.

Re: Front Panels Sample layout.

[Adrian Stoness]

Sure

On Friday, July 17, 2015, Rod Smallwood 
wrote:

> Hi Guys!
>Further to my previous email.
> If anybody would like to see the artwork I can send you a copy.
> Its in *.svg format.
>
> Regards
>
> Rod
>
>

Re: PDP 11 gear finally moved

[Jay Jaeger]

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

[Jay Jaeger]

I tend to agree with your hunch.

On 7/17/2015 1:55 PM, Todd Killingsworth wrote:
> I suspect part of the "swap'em ALL out" mentality comes from the 90's when
> some botched industrial espionage had some of the bottom-tier cap
> manufacturers using a dodgy electrolytic formula for their caps.  These
> caps would have a frequent failure rate..
> 
> While not an issue for pre-90's electronics,  it has fostered the mentality
> of full replacement for 'newer' electronics i.e. arcade/pinball machines
> 
> Todd Killingsworth
> 
> On Fri, Jul 17, 2015 at 2:42 PM, tony duell  wrote:
> 
>>>
 It is generally a good idea to re-form electrolytic capacitors in power
 supplies, and to bench check the power supplies (under some kind of
 load) before actually applying power to the whole unit.
>>>
>>> It is always a good idea to replace electrolytic capacitors in power
>> supplies.
>>
>> Could you, please, explain why? And how often should this be done? Every
>> week, every month, every year, or what?
>>
>> FWIW, the number PSU elecrtrolytics I have replaced can be counted on the
>> fingers of
>> one hand -- in unary. Well, perhaps both hands. But it's <1% of all the
>> PSU electrolytic
>> capacitors I own.
>>
>> Only 2 cases spring to mind :
>>
>> The PSU in my 11/44 had a high ESR capacitor on the +36V rail (all other
>> caps in the machine
>> were fine)
>>
>> I changed the 2 mains smoothing capacitors in my HP120 not because they
>> were electrically
>> defective (they tested fine) but because one was bulging a little on top
>> and had it exploded it would
>> have hit the neck of the CRT with all the problems that would be likely to
>> cause.
>>
>> 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...
>>
>> -tony
>>
> 

Re: PDP 11 gear finally moved

[Jay Jaeger]

That might be a little different -- much more recent - presumably in the
ear of flat screens and PCs where there have been times when
manufacturers got fed bad capacitors for their boards - which then
failed later.  IBM replaced a whole series of motherboards in one
organization that I worked at because of that (though those were not
power supply capacitors.)

On 7/17/2015 1:53 PM, 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
> 

Re: PDP 11 gear finally moved

[Jay Jaeger]

Replace - no, I don't agree - especially not for those of us who don't
have the kind of budget that your organization has.  In my experience,
for equipment of this quality and vintage, 95% or more of the time an
hour to a few hours of re-forming is all that is necessary - and as Tony
has pointed out, even that is not often really necessary.

JRJ

On 7/17/2015 1:33 PM, Rich Alderson wrote:
>> It is generally a good idea to re-form electrolytic capacitors in power
>> supplies, and to bench check the power supplies (under some kind of
>> load) before actually applying power to the whole unit.
> 
> It is always a good idea to replace electrolytic capacitors in power supplies.
> The rest of the advice is sound.
> 
> Rich
> 
> Rich Alderson
> Vintage Computing Sr. Systems Engineer
> Living Computer Museum
> 2245 1st Avenue S
> Seattle, WA 98134
> 
> mailto:ri...@livingcomputermuseum.org
> 
> http://www.LivingComputerMuseum.org/ 
> 

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: PDP 11 gear finally moved

[devin davison]

I had to do some cap replacement on some older Motorola tube radios,I have
some basic soldering skills. I was under the impression that the capacitors
in computer equipment this big from this year would have been of better
quality and it would not be an issue.

I have someone scheduled to come out tonight after i get off work and get
it out of the rack.

On Fri, Jul 17, 2015 at 3:45 PM, Brent Hilpert  wrote:

> On 2015-Jul-17, at 11:42 AM, tony duell wrote:
> >>> It is generally a good idea to re-form electrolytic capacitors in power
> >>> supplies, and to bench check the power supplies (under some kind of
> >>> load) before actually applying power to the whole unit.
> >>
> >> It is always a good idea to replace electrolytic capacitors in power
> supplies.
> >
> > Could you, please, explain why? And how often should this be done? Every
> > week, every month, every year, or what?
> >
> > FWIW, the number PSU elecrtrolytics I have replaced can be counted on
> the fingers of
> > one hand -- in unary. Well, perhaps both hands. But it's <1% of all the
> PSU electrolytic
> > capacitors I own.
> >
> > Only 2 cases spring to mind :
> >
> > The PSU in my 11/44 had a high ESR capacitor on the +36V rail (all other
> caps in the machine
> > were fine)
> >
> > I changed the 2 mains smoothing capacitors in my HP120 not because they
> were electrically
> > defective (they tested fine) but because one was bulging a little on top
> and had it exploded it would
> > have hit the neck of the CRT with all the problems that would be likely
> to cause.
> >
> > 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...
>
> This is something Tony and I are quite in agreement on.
>
> Similar to Tony, (and as mentioned in discussion on this topic a couple of
> months ago): in the solid-state category, of the many pieces of 1960s & 70s
> and later equipment I have or have serviced, the vast majority are running
> with their original capacitors.
>
> If you're dealing with a 1936 or 1952 tube radio, a knee-jerk "replace the
> capacitors" is warranted.
> If you're dealing with a 1970s computer, it isn't (IMHO). Esp. when
> they're screw-terminal 'computer-grade' caps.
>
> My own perception of the concern is that it has been perpetuated over the
> years from the vacuum tube / antique radio arena. The issue of capacitors
> "drying out" dates from the days (1920s,early 30s) when electrolytics
> actually were filled with an active liquid which actually did dry up.
> "Dry electrolytics" were developed in the 1930s, and while early dry
> electrolytics also warrant replacement, the chemistry and techniques have
> seen a few improvements in the many intervening years, and solid-state
> equipment is not placing the same stresses on caps as tube equipment.
>
> In other arenas it's a real issue, in a modern arena it is largely lore.
>
> The point of electrolytic caps is to form an oxide to be the dielectric,
> formed (in part) out of the electrolyte, and while I'm no expert on the
> chemistry, I will point out the oxidised state is 'the' or 'a' low energy
> state, and hence relatively stable. Rust doesn't normally undo itself.
>
>

Re: PDP 11 gear finally moved

[devin davison]

I was operating the panel when i first got it, now the numbers do not light
up, panel is unresponsive, and run light stays lit.(just describing the
behavior, i will not start it back up till I work on the power supply)

On Fri, Jul 17, 2015 at 3:50 PM, devin davison  wrote:

> I had to do some cap replacement on some older Motorola tube radios,I have
> some basic soldering skills. I was under the impression that the capacitors
> in computer equipment this big from this year would have been of better
> quality and it would not be an issue.
>
> I have someone scheduled to come out tonight after i get off work and get
> it out of the rack.
>
> On Fri, Jul 17, 2015 at 3:45 PM, Brent Hilpert  wrote:
>
>> On 2015-Jul-17, at 11:42 AM, tony duell wrote:
>> >>> It is generally a good idea to re-form electrolytic capacitors in
>> power
>> >>> supplies, and to bench check the power supplies (under some kind of
>> >>> load) before actually applying power to the whole unit.
>> >>
>> >> It is always a good idea to replace electrolytic capacitors in power
>> supplies.
>> >
>> > Could you, please, explain why? And how often should this be done? Every
>> > week, every month, every year, or what?
>> >
>> > FWIW, the number PSU elecrtrolytics I have replaced can be counted on
>> the fingers of
>> > one hand -- in unary. Well, perhaps both hands. But it's <1% of all the
>> PSU electrolytic
>> > capacitors I own.
>> >
>> > Only 2 cases spring to mind :
>> >
>> > The PSU in my 11/44 had a high ESR capacitor on the +36V rail (all
>> other caps in the machine
>> > were fine)
>> >
>> > I changed the 2 mains smoothing capacitors in my HP120 not because they
>> were electrically
>> > defective (they tested fine) but because one was bulging a little on
>> top and had it exploded it would
>> > have hit the neck of the CRT with all the problems that would be likely
>> to cause.
>> >
>> > 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...
>>
>> This is something Tony and I are quite in agreement on.
>>
>> Similar to Tony, (and as mentioned in discussion on this topic a couple
>> of months ago): in the solid-state category, of the many pieces of 1960s &
>> 70s and later equipment I have or have serviced, the vast majority are
>> running with their original capacitors.
>>
>> If you're dealing with a 1936 or 1952 tube radio, a knee-jerk "replace
>> the capacitors" is warranted.
>> If you're dealing with a 1970s computer, it isn't (IMHO). Esp. when
>> they're screw-terminal 'computer-grade' caps.
>>
>> My own perception of the concern is that it has been perpetuated over the
>> years from the vacuum tube / antique radio arena. The issue of capacitors
>> "drying out" dates from the days (1920s,early 30s) when electrolytics
>> actually were filled with an active liquid which actually did dry up.
>> "Dry electrolytics" were developed in the 1930s, and while early dry
>> electrolytics also warrant replacement, the chemistry and techniques have
>> seen a few improvements in the many intervening years, and solid-state
>> equipment is not placing the same stresses on caps as tube equipment.
>>
>> In other arenas it's a real issue, in a modern arena it is largely lore.
>>
>> The point of electrolytic caps is to form an oxide to be the dielectric,
>> formed (in part) out of the electrolyte, and while I'm no expert on the
>> chemistry, I will point out the oxidised state is 'the' or 'a' low energy
>> state, and hence relatively stable. Rust doesn't normally undo itself.
>>
>>
>

Re: PDP 11 gear finally moved

[devin davison]

Thank you for the detailed information. I need to figure out how im going
to get it out of the rack and moved to a place where i can test it over the
next couple days where it will not be in the way.  Ill find some way to do
a dummy load and do an extended test to be sure the supply is working
properly. All fingers crossed, god it better not have damaged any of the
boards, i do not know where i would get replacements.It took years for me
to get the machine, who knows how long it would take to find a specific
board that is bad. I did buy an oscillicope and a logic analyzer well in
advance in preparation for getting this machine, however short of pressing
the power button no clue how to use them or basic troubleshooting
procedures. Guess i just have to learn by doing

On Fri, Jul 17, 2015 at 3:23 PM, tony duell  wrote:

>
> > When I repaired my VT100s I had to replace all the electrolytic caps on
> the
> > monitor control board to cure the screen wobble. Before doing so I had
> > reformed them all and I had tested them all for ESR and they had all
> tested
> > fine so I was unable to determine which of them was the bad one. Perhaps
> > there is other more professional test equipment I could use that would
> have
> > helped, I don't know. I did keep all the original caps though
> (somewhere).
>
> Are you saying that if you put any of the original capacitors back
> (leaving new
> ones in all other locations) you get screen wobble. If so, I am not sure I
> believe you. It's been some years since I repaired a VT100, but from what I
> remember there are plenty of capacitors that simply could not cause
> screen wobble no matter what they were doing.
>
> Or did you recap the board and find that it then worked. In which case (a)
> perhaps only one of the capacitors was faulty or (b) it was actually a dry
> joint.
>
> -tony
>

RE: PDP 11 gear finally moved

[Robert Jarratt]

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of tony
duell
> Sent: 17 July 2015 20:23
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: RE: PDP 11 gear finally moved
> 
> 
> > When I repaired my VT100s I had to replace all the electrolytic caps
> > on the monitor control board to cure the screen wobble. Before doing
> > so I had reformed them all and I had tested them all for ESR and they
> > had all tested fine so I was unable to determine which of them was the
> > bad one. Perhaps there is other more professional test equipment I
> > could use that would have helped, I don't know. I did keep all the
original caps
> though (somewhere).
> 
> Are you saying that if you put any of the original capacitors back
(leaving new
> ones in all other locations) you get screen wobble. If so, I am not sure I
believe
> you. It's been some years since I repaired a VT100, but from what I
remember
> there are plenty of capacitors that simply could not cause screen wobble
no
> matter what they were doing.
> 
> Or did you recap the board and find that it then worked. In which case (a)
> perhaps only one of the capacitors was faulty or (b) it was actually a dry
joint.
> 
> -tony
> =

I am saying that I recapped the entire board, so one or more of them must
have been bad. I agree it could have been a dry joint, but I am not going to
put them all back just to check :-) This happened on *two* of these boards,
so either I had two dry joints, or two bad caps.

Regards

Rob

Re: PDP 11 gear finally moved

[Brent Hilpert]

On 2015-Jul-17, at 11:42 AM, tony duell wrote:
>>> It is generally a good idea to re-form electrolytic capacitors in power
>>> supplies, and to bench check the power supplies (under some kind of
>>> load) before actually applying power to the whole unit.
>> 
>> It is always a good idea to replace electrolytic capacitors in power 
>> supplies.
> 
> Could you, please, explain why? And how often should this be done? Every
> week, every month, every year, or what?
> 
> FWIW, the number PSU elecrtrolytics I have replaced can be counted on the 
> fingers of
> one hand -- in unary. Well, perhaps both hands. But it's <1% of all the PSU 
> electrolytic
> capacitors I own. 
> 
> Only 2 cases spring to mind :
> 
> The PSU in my 11/44 had a high ESR capacitor on the +36V rail (all other caps 
> in the machine
> were fine)
> 
> I changed the 2 mains smoothing capacitors in my HP120 not because they were 
> electrically 
> defective (they tested fine) but because one was bulging a little on top and 
> had it exploded it would
> have hit the neck of the CRT with all the problems that would be likely to 
> cause.
> 
> 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...

This is something Tony and I are quite in agreement on.

Similar to Tony, (and as mentioned in discussion on this topic a couple of 
months ago): in the solid-state category, of the many pieces of 1960s & 70s and 
later equipment I have or have serviced, the vast majority are running with 
their original capacitors.

If you're dealing with a 1936 or 1952 tube radio, a knee-jerk "replace the 
capacitors" is warranted.
If you're dealing with a 1970s computer, it isn't (IMHO). Esp. when they're 
screw-terminal 'computer-grade' caps.

My own perception of the concern is that it has been perpetuated over the years 
from the vacuum tube / antique radio arena. The issue of capacitors "drying 
out" dates from the days (1920s,early 30s) when electrolytics actually were 
filled with an active liquid which actually did dry up.
"Dry electrolytics" were developed in the 1930s, and while early dry 
electrolytics also warrant replacement, the chemistry and techniques have seen 
a few improvements in the many intervening years, and solid-state equipment is 
not placing the same stresses on caps as tube equipment.

In other arenas it's a real issue, in a modern arena it is largely lore.

The point of electrolytic caps is to form an oxide to be the dielectric, formed 
(in part) out of the electrolyte, and while I'm no expert on the chemistry, I 
will point out the oxidised state is 'the' or 'a' low energy state, and hence 
relatively stable. Rust doesn't normally undo itself.

RE: PDP 11 gear finally moved

[tony duell]

> When I repaired my VT100s I had to replace all the electrolytic caps on the
> monitor control board to cure the screen wobble. Before doing so I had
> reformed them all and I had tested them all for ESR and they had all tested
> fine so I was unable to determine which of them was the bad one. Perhaps
> there is other more professional test equipment I could use that would have
> helped, I don't know. I did keep all the original caps though (somewhere).

Are you saying that if you put any of the original capacitors back (leaving new 
ones in all other locations) you get screen wobble. If so, I am not sure I 
believe you. It's been some years since I repaired a VT100, but from what I
remember there are plenty of capacitors that simply could not cause
screen wobble no matter what they were doing.

Or did you recap the board and find that it then worked. In which case (a)
perhaps only one of the capacitors was faulty or (b) it was actually a dry
joint.

-tony

RE: PDP 11 gear finally moved

[Robert Jarratt]

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of tony
duell
> Sent: 17 July 2015 19:56
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: RE: PDP 11 gear finally moved
> 
> >
> > 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
> 
> This could be taken to show that modern capacitors are not reliable, and
given
> that there are plenty of 40-year-old ones still in use in various classic
> computers here it would be better to leave them as-is
> 
> More seriously, a lot of modern consumer stuff seems to have
marginally-rated
> capacitors (and the use of 85 degree ones doesn't help). Possibly on those
it is a
> good idea to replace them. But the ones in PDP11s were good quality at the
> start and were over-spec'd in general.
> 
> > 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.
> 
> Ah but it can hurt. Damage to the PCB (unlikely, sure), the new part might
be
> faulty and thus introduce more faults, you might make an error fitting it,
and so
> on. I prefer to only replace that which needs replacing.
> 
> -tony
> =

When I repaired my VT100s I had to replace all the electrolytic caps on the
monitor control board to cure the screen wobble. Before doing so I had
reformed them all and I had tested them all for ESR and they had all tested
fine so I was unable to determine which of them was the bad one. Perhaps
there is other more professional test equipment I could use that would have
helped, I don't know. I did keep all the original caps though (somewhere).

Regards

Rob

RE: PDP 11 gear finally moved

[tony duell]

> 
> 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

This could be taken to show that modern capacitors are not reliable, and given
that there are plenty of 40-year-old ones still in use in various classic 
computers here
it would be better to leave them as-is

More seriously, a lot of modern consumer stuff seems to have marginally-rated 
capacitors
(and the use of 85 degree ones doesn't help). Possibly on those it is a good 
idea to 
replace them. But the ones in PDP11s were good quality at the start and were 
over-spec'd
in general. 

> 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.

Ah but it can hurt. Damage to the PCB (unlikely, sure), the new part might be 
faulty
and thus introduce more faults, you might make an error fitting it, and so on. 
I prefer
to only replace that which needs replacing.

-tony

Re: PDP 11 gear finally moved

[wulfman]

some are good some are bad.

http://www.badcaps.net/


here is all the info you ever need on today's bad caps
not so much on yesteryears bad caps



On 7/17/2015 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
>


-- 
The contents of this e-mail and any attachments are intended solely for the use 
of the named
addressee(s) and may contain confidential and/or privileged information. Any 
unauthorized use,
copying, disclosure, or distribution of the contents of this e-mail is strictly 
prohibited by
the sender and may be unlawful. If you are not the intended recipient, please 
notify the sender
immediately and delete this e-mail.

Re: PDP 11 gear finally moved

[Todd Killingsworth]

I suspect part of the "swap'em ALL out" mentality comes from the 90's when
some botched industrial espionage had some of the bottom-tier cap
manufacturers using a dodgy electrolytic formula for their caps.  These
caps would have a frequent failure rate..

While not an issue for pre-90's electronics,  it has fostered the mentality
of full replacement for 'newer' electronics i.e. arcade/pinball machines

Todd Killingsworth

On Fri, Jul 17, 2015 at 2:42 PM, tony duell  wrote:

> >
> > > It is generally a good idea to re-form electrolytic capacitors in power
> > > supplies, and to bench check the power supplies (under some kind of
> > > load) before actually applying power to the whole unit.
> >
> > It is always a good idea to replace electrolytic capacitors in power
> supplies.
>
> Could you, please, explain why? And how often should this be done? Every
> week, every month, every year, or what?
>
> FWIW, the number PSU elecrtrolytics I have replaced can be counted on the
> fingers of
> one hand -- in unary. Well, perhaps both hands. But it's <1% of all the
> PSU electrolytic
> capacitors I own.
>
> Only 2 cases spring to mind :
>
> The PSU in my 11/44 had a high ESR capacitor on the +36V rail (all other
> caps in the machine
> were fine)
>
> I changed the 2 mains smoothing capacitors in my HP120 not because they
> were electrically
> defective (they tested fine) but because one was bulging a little on top
> and had it exploded it would
> have hit the neck of the CRT with all the problems that would be likely to
> cause.
>
> 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...
>
> -tony
>

Re: PDP 11 gear finally moved

[Mouse]

> 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

RE: PDP 11 gear finally moved

[tony duell]

> 
> > It is generally a good idea to re-form electrolytic capacitors in power
> > supplies, and to bench check the power supplies (under some kind of
> > load) before actually applying power to the whole unit.
> 
> It is always a good idea to replace electrolytic capacitors in power supplies.

Could you, please, explain why? And how often should this be done? Every
week, every month, every year, or what?

FWIW, the number PSU elecrtrolytics I have replaced can be counted on the 
fingers of
one hand -- in unary. Well, perhaps both hands. But it's <1% of all the PSU 
electrolytic
capacitors I own. 

Only 2 cases spring to mind :

The PSU in my 11/44 had a high ESR capacitor on the +36V rail (all other caps 
in the machine
were fine)

I changed the 2 mains smoothing capacitors in my HP120 not because they were 
electrically 
defective (they tested fine) but because one was bulging a little on top and 
had it exploded it would
have hit the neck of the CRT with all the problems that would be likely to 
cause.

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...

-tony

RE: PDP 11 gear finally moved

[tony duell]

> 
> I was trying to enter a short program at the front panel and there was a
> clicking sound followed by a burning smell. I cut the power, the front
> panel is unresponsive now, so I'm going to need to look over the power

Did you see anything on the panel when it died (was the numeric display still
alight) ? 

You had better hope that the +5V line didn't go high and cook all the ICs in the
machine. DEC PSUs of that vintage do have crowbar circuits though.

> supply for starters. He did include a second empty PDP 11/34 chassis,
> perhaps the power supply in that one is in better condition.

The PSU in this machine is relatively repairer-friendly. 

There is a big mains transformer in the centre of the PSU chassis (at the back 
of the CPU). It
takes mains in (there are 2 primary windings, each 115V, they are connected in 
parallel for US
mains and series for European mains). It has several secondaries, each of about 
20V-30V AC

Under the mains transformer is a little unit that contains the mains switching 
relay and control
circuits, and a simple linear PSU for the +15V rail. I think the LTC (line time 
clock), ACLO and DCLO
(power failure signals) come from that too. The main supply rails (+5V and 
-15V) come from 'bricks'
that fit either side of the transformer. These are swtiching regulators that 
take in the 20V or so from
the transformer and bring it down to the desired voltage. Although they are 
switchers, the maximum 
voltage inside is just the rectified input (say about 40V DC) and is thus a lot 
nicer to work on than 
a mains-operated switcher. The bricks are based round the 723 IC along with 
some transistors, an 
inductor, flyback diode, capacitors, etc.

What I would do is disconnect the logic backplane power (at the distribution 
connectors under the PSU)
then take the PSU covers off, take out the bottom 2 screws each side and loosen 
the top on so the PSU can 
hinge away from the CPU and remove the power bricks. Power up the transformer 
on its own (maybe with
a series light bub) and check that is OK. Then try to debug the bricks. If you 
have a bench PSU with current
limiting run them (one at a time) off that (they will happing run from a DC 
input) and see what happens. 
The +5V brick just needs the 20V-30V input, the -15V one _also_ needs a +15V 
supply.

-tony

Re: PDP 11 gear finally moved

[Jay Jaeger]

It is generally a good idea to re-form electrolytic capacitors in power
supplies, and to bench check the power supplies (under some kind of
load) before actually applying power to the whole unit.

JRJ

On 7/17/2015 11:49 AM, devin davison wrote:
> Devin here, I had asked for advice on how to move a PDP 11 as well as how
> to lock the heads on the RL Drives. It was quite a move. Ive never driven
> in a large city before, dealing with traffic was more trouble than it was
> to move and load up the equipment. Anyhow, i put a few images of what I got
> up on a postimage gallery, which can be viewed here :
> 
> http://postimg.org/gallery/1xuwq2s6y/
> 
> It was at least working for a hour or so
> I was trying to enter a short program at the front panel and there was a
> clicking sound followed by a burning smell. I cut the power, the front
> panel is unresponsive now, so I'm going to need to look over the power
> supply for starters. He did include a second empty PDP 11/34 chassis,
> perhaps the power supply in that one is in better condition.
> 
> --Devin
> 

RE: PDP 11 gear finally moved

[tony duell]

> It is generally a good idea to re-form electrolytic capacitors in power
> supplies, and to bench check the power supplies (under some kind of
> load) before actually applying power to the whole unit.

I am not sure either would have done much good here. The OP said it
ran OK for an hour or so, when you test a PSU on dummy load you 
typically do it for a lot less time than that, Incidentally, DEC PSUs
of this type run fine with no load in my experience

Also I have found the capacitors in these units to be very reliable. They
can fail, of course, but virtually all the DEC bricks I have are on their
original capacitors. I think I've replaced more chopper transistors than
capacitors in these.

-tony

RE: PDP 11 gear finally moved

[Rich Alderson]

> It is generally a good idea to re-form electrolytic capacitors in power
> supplies, and to bench check the power supplies (under some kind of
> load) before actually applying power to the whole unit.

It is always a good idea to replace electrolytic capacitors in power supplies.
The rest of the advice is sound.

Rich

Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134

mailto:ri...@livingcomputermuseum.org

http://www.LivingComputerMuseum.org/ 

Re: OpenVMS Alpha V7.3

[Sean Caron]

I'm using a genuine DEC RRD45 so no sector size issue and it's worked fine
with burned CDs in the past to load my VAX machines ... I've never had too
much trouble with burns ... I think I just got a funky image from HP ...
other people have reported issues with it ... I could see the RRD45 getting
hung up more on it being a "700 MB CD" rather than it being a burn ... but
the RRD45 is the newest drive I've got.

Best,

Sean


On Fri, Jul 17, 2015 at 12:22 PM, John Willis 
wrote:

> On Fri, Jul 17, 2015 at 7:53 AM, william degnan 
> wrote:
>
> > related question - I was not able to make a bootable/readable image from
> > the ISO I have 7.3, although it might have been a bad source.  Is there a
> > best way/ best software to make a usable 7.3 install CD that will work in
> > an Alpha?   Just curious as to why I was not able to make it work.  I
> make
> > CD's all of the time from ISO, but maybe I need to do more research on
> the
> > subject as far as size and set up go for an Alpha-bootable CD, or CDRW
> type
> > I need to use, etc.   I'd offer my ISO, but I don't know if it's good.
> > Bill
> >
>
> Your Alpha system may not support reading burned CDs at all. I know mine
> doesn't.
>

keys, motorola 88k system series 900

[emanuel stiebler]

With all this talking about keys ...

Anybody know where to get a spare one for the system above?

Cheers & thanks ...

PDP 11 gear finally moved

[devin davison]

Devin here, I had asked for advice on how to move a PDP 11 as well as how
to lock the heads on the RL Drives. It was quite a move. Ive never driven
in a large city before, dealing with traffic was more trouble than it was
to move and load up the equipment. Anyhow, i put a few images of what I got
up on a postimage gallery, which can be viewed here :

http://postimg.org/gallery/1xuwq2s6y/

It was at least working for a hour or so
I was trying to enter a short program at the front panel and there was a
clicking sound followed by a burning smell. I cut the power, the front
panel is unresponsive now, so I'm going to need to look over the power
supply for starters. He did include a second empty PDP 11/34 chassis,
perhaps the power supply in that one is in better condition.

--Devin

Re: OpenVMS Alpha V7.3

[william degnan]

thanks for the info.  The Alpha in question is a 2100 4/275.  It works
enough to connect to the web but I need to fix one of the drives.

On Fri, Jul 17, 2015 at 12:22 PM, John Willis 
wrote:

> On Fri, Jul 17, 2015 at 7:53 AM, william degnan 
> wrote:
>
> > related question - I was not able to make a bootable/readable image from
> > the ISO I have 7.3, although it might have been a bad source.  Is there a
> > best way/ best software to make a usable 7.3 install CD that will work in
> > an Alpha?   Just curious as to why I was not able to make it work.  I
> make
> > CD's all of the time from ISO, but maybe I need to do more research on
> the
> > subject as far as size and set up go for an Alpha-bootable CD, or CDRW
> type
> > I need to use, etc.   I'd offer my ISO, but I don't know if it's good.
> > Bill
> >
>
> Your Alpha system may not support reading burned CDs at all. I know mine
> doesn't.
>

RE: Reproducing old machines with newer technology

[tony duell]

> That wasn't all that uncommon in the microprocessor world--once the
> price dropped sufficiently, doing multiuser applications by giving each
> user their own CPU was practical.  Molecular was another outfit that did
> practically the same thing.
> 
> Dual-CPU setups, where the "weaker" of the two CPUs was in control of
> the "stronger" one were even more numerous--just consider the number of
> "add in" processor cards for the PC archicture.  68K, NS32xxx...you name
> a CPU, it's probably been on an ISA card.

The common UK example is the BBC micro. It was a complete useable 
6502-based computer, but could have a 'second processor' added 
via an interface known as the 'tube'[1] The 6502 in the BBC micro handled
I/O functions, while user programs ran on the second processor. The ones
I know of are
6502 (ran BBC software including BBC BASIC, but faster than the plain BBC)
Z80 (ran CP/M)
32016 (ran something called PANOS)
ARM 

There were also a couple of (fairly rare) Acorn machines which consisted of 
a BBC B+ mainboard in a case with a built-in monitor and disk drives and
a second processor board. The ABC (Acorn Business Computer) had a Z80, the
ACW (Acorn Cambridge Workstation) had a 32016

[1] So called (officially) because it provided a 'tube' to pass information 
between
the 2 processors. But of course 'Tube' is a common name for the London 
Underground
(subway) and 'Bus' is anotherr form of public transport. As a total aside, the 
system
bus on the Tatung Einstein was called the 'Pipe', presumably a pun on 'tube', 
for all
that machine never took second processors.

-tony

Re: OpenVMS Alpha V7.3

[John Willis]

On Fri, Jul 17, 2015 at 7:53 AM, william degnan 
wrote:

> related question - I was not able to make a bootable/readable image from
> the ISO I have 7.3, although it might have been a bad source.  Is there a
> best way/ best software to make a usable 7.3 install CD that will work in
> an Alpha?   Just curious as to why I was not able to make it work.  I make
> CD's all of the time from ISO, but maybe I need to do more research on the
> subject as far as size and set up go for an Alpha-bootable CD, or CDRW type
> I need to use, etc.   I'd offer my ISO, but I don't know if it's good.
> Bill
>

Your Alpha system may not support reading burned CDs at all. I know mine
doesn't.

Re: OpenVMS Alpha V7.3

[Sean Caron]

Thanks, Richard! I'll try some of the ISOs I received and failing that I
might take you up on your offer. I'm going to get this box running VMS one
way or the other :O

Best,

Sean


On Fri, Jul 17, 2015 at 11:25 AM, Richard Loken <
richar...@admin.athabascau.ca> wrote:

> On Thu, 16 Jul 2015, Sean Caron wrote:
>
> > Anyone got an ISO handy? Trying to get my 3000/400 up; V7.0 firmware; and
> > it does not like the OpenVMS V8.4 ISOs I got from HP ... I do have a
> valid
> > Hobbyist license ... please chat with me off-list?
>
> I have a 7.2 CDrom and a 7.3-1 CDrom that I can send you if you cannot find
> an ISO.
>
> --
>Richard Loken VE6BSV, Unix System Administrator : "Anybody can be a
> father
>Athabasca University:  but you have to earn
>Athabasca, Alberta Canada   :  the title of 'daddy'"
>** richar...@admin.athabascau.ca ** :  - Lynn Johnston
>
>

Re: OpenVMS Alpha V7.3

[Sean Caron]

I've got a few to try so I'll burn those today and see what happens. For
the 8.4 disc I have, I used the same process to burn the disc that I did
for OpenVMS VAX V7.3 ... I just copied the *.iso to a Mac and used Disk
Utility to burn the *.iso just to a regular CD-R. For V7.3 VAX this
produced a perfectly good bootable CD, but on Alpha, when I try to boot the
disc, it looks like it'll get started, but it will churn for a little while
but eventually come back and say it can't find the file SYSBOOT.EXE.

I know the monitor environment variable BOOT_OSFLAGS needs to be set to 0,0
and I've ensured that's done ...

I definitely get the sense that my Alpha is a little more "finicky" than my
VAXen are ... seems to be kind of picky about what it will run and what
hardware it will work with! I'll try these disc images today and write back
with my experiences; I hope I can get at least one of them to come up :O

Tru64 and NetBSD boot fine on this machine but I've never been able to get
it to run OpenVMS ... I'm trying to rectify that this week :O

Best,

Sean


On Fri, Jul 17, 2015 at 9:53 AM, william degnan 
wrote:

> related question - I was not able to make a bootable/readable image from
> the ISO I have 7.3, although it might have been a bad source.  Is there a
> best way/ best software to make a usable 7.3 install CD that will work in
> an Alpha?   Just curious as to why I was not able to make it work.  I make
> CD's all of the time from ISO, but maybe I need to do more research on the
> subject as far as size and set up go for an Alpha-bootable CD, or CDRW type
> I need to use, etc.   I'd offer my ISO, but I don't know if it's good.
> Bill
>
> On Thu, Jul 16, 2015 at 11:28 PM, Sean Caron  wrote:
>
> > Maybe my RRD45 doesn't like the "700 MB CD" ... does anyone know if it's
> > possible to bootstrap the installation from my existing CISC VAXcluster
> > with the ALPHA084*.ISO images I got from HP? Cross-platform MOP boot from
> > the VAX with the *.ISO images mounted locally on the VAX, perhaps? I
> assume
> > it's just a save set that's restored with the BACKUP command once one can
> > actually get to the point of a DCL prompt on the machine?
> >
> > Best,
> >
> > Sean
> >
> >
> > On Thu, Jul 16, 2015 at 7:19 PM, Sean Caron  wrote:
> >
> > > Anyone got an ISO handy? Trying to get my 3000/400 up; V7.0 firmware;
> and
> > > it does not like the OpenVMS V8.4 ISOs I got from HP ... I do have a
> > valid
> > > Hobbyist license ... please chat with me off-list?
> > >
> > > Thanks,
> > >
> > > Sean
> > >
> > >
> >
>

Re: OpenVMS Alpha V7.3

[Sean Caron]

I'm all set; thanks to all that responded! I've got a few different *.isos
to try and hopefully one of them will be palatable to my old 3000/400 ...
I'd rather run VMS on it than Tru64 :O I truly appreciate it!

Best,

Sean


On Thu, Jul 16, 2015 at 7:19 PM, Sean Caron  wrote:

> Anyone got an ISO handy? Trying to get my 3000/400 up; V7.0 firmware; and
> it does not like the OpenVMS V8.4 ISOs I got from HP ... I do have a valid
> Hobbyist license ... please chat with me off-list?
>
> Thanks,
>
> Sean
>
>

Re: Reproducing old machines with newer technology

[Chuck Guzis]

On 07/16/2015 11:45 AM, Mike Stein wrote:


Not the same thing of course but remotely on-topic, and I never miss an
opportunity to put in a plug for Cromemco:

By comparison, Cromemco used semi-autonomous 4MHz Z80A SBCs for their
I/O processors,  with 16KB of local RAM and up to 32KB of ROM;
communication with peripheral cards is via a separate 50-pin 'C-Bus'.


That wasn't all that uncommon in the microprocessor world--once the 
price dropped sufficiently, doing multiuser applications by giving each 
user their own CPU was practical.  Molecular was another outfit that did 
practically the same thing.


Dual-CPU setups, where the "weaker" of the two CPUs was in control of 
the "stronger" one were even more numerous--just consider the number of 
"add in" processor cards for the PC archicture.  68K, NS32xxx...you name 
a CPU, it's probably been on an ISA card.


And there's the veneered and generated Radio Shack 68K series (16, 16B, 
6000) where it's the Z80 that starts things and controls the show 
initially, even if you're running Xenix.


In pretty much all cases, the system is capable of running without the 
"stronger" CPU.


--Chuck

Re: OpenVMS Alpha V7.3

[Ian S. King]

Sector size?

On Fri, Jul 17, 2015 at 8:25 AM, Richard Loken <
richar...@admin.athabascau.ca> wrote:

> On Thu, 16 Jul 2015, Sean Caron wrote:
>
> > Anyone got an ISO handy? Trying to get my 3000/400 up; V7.0 firmware; and
> > it does not like the OpenVMS V8.4 ISOs I got from HP ... I do have a
> valid
> > Hobbyist license ... please chat with me off-list?
>
> I have a 7.2 CDrom and a 7.3-1 CDrom that I can send you if you cannot find
> an ISO.
>
> --
>Richard Loken VE6BSV, Unix System Administrator : "Anybody can be a
> father
>Athabasca University:  but you have to earn
>Athabasca, Alberta Canada   :  the title of 'daddy'"
>** richar...@admin.athabascau.ca ** :  - Lynn Johnston
>
>


-- 
Ian S. King, MSIS, MSCS, Ph.D. Candidate
The Information School 

Archivist, Voices From the Rwanda Tribunal 
Value Sensitive Design Research Lab 

University of Washington

There is an old Vulcan saying: "Only Nixon could go to China."

Re: OpenVMS Alpha V7.3

[Richard Loken]

On Thu, 16 Jul 2015, Sean Caron wrote:

> Anyone got an ISO handy? Trying to get my 3000/400 up; V7.0 firmware; and
> it does not like the OpenVMS V8.4 ISOs I got from HP ... I do have a valid
> Hobbyist license ... please chat with me off-list?

I have a 7.2 CDrom and a 7.3-1 CDrom that I can send you if you cannot find
an ISO.

-- 
   Richard Loken VE6BSV, Unix System Administrator : "Anybody can be a father
   Athabasca University:  but you have to earn
   Athabasca, Alberta Canada   :  the title of 'daddy'"
   ** richar...@admin.athabascau.ca ** :  - Lynn Johnston

Re: OpenVMS Alpha V7.3

[william degnan]

related question - I was not able to make a bootable/readable image from
the ISO I have 7.3, although it might have been a bad source.  Is there a
best way/ best software to make a usable 7.3 install CD that will work in
an Alpha?   Just curious as to why I was not able to make it work.  I make
CD's all of the time from ISO, but maybe I need to do more research on the
subject as far as size and set up go for an Alpha-bootable CD, or CDRW type
I need to use, etc.   I'd offer my ISO, but I don't know if it's good.
Bill

On Thu, Jul 16, 2015 at 11:28 PM, Sean Caron  wrote:

> Maybe my RRD45 doesn't like the "700 MB CD" ... does anyone know if it's
> possible to bootstrap the installation from my existing CISC VAXcluster
> with the ALPHA084*.ISO images I got from HP? Cross-platform MOP boot from
> the VAX with the *.ISO images mounted locally on the VAX, perhaps? I assume
> it's just a save set that's restored with the BACKUP command once one can
> actually get to the point of a DCL prompt on the machine?
>
> Best,
>
> Sean
>
>
> On Thu, Jul 16, 2015 at 7:19 PM, Sean Caron  wrote:
>
> > Anyone got an ISO handy? Trying to get my 3000/400 up; V7.0 firmware; and
> > it does not like the OpenVMS V8.4 ISOs I got from HP ... I do have a
> valid
> > Hobbyist license ... please chat with me off-list?
> >
> > Thanks,
> >
> > Sean
> >
> >
>

Front Panels Sample layout.

[Rod Smallwood]

Hi Guys!
   Further to my previous email.
If anybody would like to see the artwork I can send you a copy.
Its in *.svg format.

Regards

Rod

PDP8/e front panels A and B

[Rod Smallwood]

Hi Guys!
  I now have prototype artwork for the two types of 8/e 
front panel.

They differ only in the switch markings.
They do both have the same extra (but cosmetic only) features over the 
first run.


Regards

Rod