Re: This Is Such An Exciting Listing!

[Michael Mulhern via cctalk]

Comment to follow.

On Sat, 19 Aug 2017 at 9:14 am, Rob Jarratt via cctalk <
cctalk@classiccmp.org> wrote:

> http://www.ebay.co.uk/itm/182707649701
>
>
>
> --


*Blog: RetroRetrospective – Fun today with yesterday's gear……..
*
*Podcast*: *Retro Computing Roundtable * (Co-Host)

Re: DCC-116 E / DATA GENERAL NOVA 2/10 / Nixdorf 620 - Restoring and restarting

[Curious Marc via cctalk]

Great work, you have isolated the supply fault. Looks like it's not regulating, 
but the fact that it starts at 5V tells me it actually is, at low current 
drain. Are you *really really* sure the filtering caps are good *at rated 
voltage* (we had a recent case of caps that tested perfect with my low voltage 
tester but were duds at their rated voltage)? Bad caps would cause something 
like this. If not I'd usually start to check the regulating power transistors. 
Could be anything else of course, having the schematics would allow for a much 
more intelligent conversation instead of blind speculation.
Marc

On Aug 18, 2017, at 10:25 AM, Dominique Carlier via cctalk 
 wrote:

Some news !

Following a risky way (but I did not see how to do otherwise), I deactivated 
the Power Fail by hiding the contact number 23 of the two power supplies.
The idea was to avoid automatic protection by lowering the regulated voltages 
(+5V and 15V) and see first which unit was involved (G1 or G2), and also which 
voltages became weak, at what level it is lowered, and according to which board 
(model or number of connected boards).

Results of the observations:
- This is definitely the regulated +5V of the G2 power supply. More I add 
boards more the + 5v level goes down. +5v, +4.8v, +3.6v, +2.9v. It remains 
stable however with just the CPU and the three core memory boards, it becomes 
difficult for the power supply when I add boards in addition to these.
- This is definitely not a problem at the level of the Power Fail circuit.
- The big capacitors are not in fault (I rechecked twice).
- So this maybe a problem at the level of the regulation itself, the +5V 
balancing system ?

Question: a faulty voltage regulator can behave in this way? I always thought 
it worked or it did not work, but not between the two states depending on the 
charge.

Anyway, suggestions are always welcome ;-)

PS : I'm starting to want to put another power supply for that regulated +5V, 
and bypass the +5V regulated of G2, but it would be a shame and not in the 
spirit of a restoration in my opinion.




 Forwarded Message 
Subject:Re: DCC-116 E / DATA GENERAL NOVA 2/10 / Nixdorf 620 - Restoring 
and restarting
Date:Wed, 16 Aug 2017 23:33:31 +0200
From:Dominique Carlier 
To:Christian Kennedy via cctalk 



Hi !

I finally find some time to work again on my D-116, try to find the
problem(s), thus principally at the level of PSUs.
As you suggested, I inspected particularly the large capacitors of both
power supplies. I replaced those that appeared suspicious according to
the results via my ESR meter, but note that this one is not supposed to
be able to verify the capacitors of more than 22000μF. I have also some
doubt about the results (capacitor working with a real charge or not).

Anyway, unfortunately the problem is still there. I don't know where to
search now. If I understand well, the two power supplies can cause a
Power Fail if one of the regulated voltages were out of range. At this
point I do not know which of the two is in fault, because when the Power
Fail is active the + 5V is automatically dropped around 1.5V.
Following the schematics I have focused my attention on the value of
some resistors with an important role in triggering this state (eg R18).
I found nothing abnormal, I checked all the capacitors, a large package
of resistances.

At this point what I know is that I can simultaneously connect the CPU
board and the three core memory boards without problem. If I add the
controller board for the removable hard disk drive or for the tape ->
Power Fail.
Interesting thing: if I connect only the CPU board and the disk
controller: Power Fail too. Maybe the PSU in default is the one that
supply the + 5V for the boards in the upper part of the rack? (slot 1
for the CPU, solt 4, 5 and 7 for the mem, slot 10 and 12 for tape and hdd)

I can provide pictures, schematics, ...

Regardless of this failure, I try to find information about what I could
install as an operating system on that big beast. If you have too any
ideas about that?

I would like to be able to do simple tasks such as managing files
(copying files from disk to tape and vice versa), being able to create
directories and sub directories, writing text, print on my drum printer,
programming in a simple language such as BASIC, and also, if I find a
communication board (on the CPU-board I don't found any trace of
components that evoke me an RS-232 interface), communicate with another
machine, print on a teletype ... Does this seem possible for you with
this type of machine? If yes, with which OS?

I took tons of pictures of the machine from all angles, I will post them
soon ;-)

Dominique

> 
>> If I removes all the boards (printer, core memory, scanner, disk
>> controller, etc.), the Power Fail light eventually goes out, I get again
>> the 5VDC, so the power has become "too weak" to power the 

Re: This Is Such An Exciting Listing!

[dwight via cctalk]

These are notoriously bad. Most radio repairers replace them without even 
measuring them to see if they leak.

"black beauties"

Tinker Dwight



From: cctalk  on behalf of Jon Elson via cctalk 

Sent: Friday, August 18, 2017 8:59:26 PM
To: couryho...@aol.com; gene...@ezwind.net; Discussion@
Subject: Re: This Is Such An Exciting Listing!

On 08/18/2017 09:32 PM, Ed via cctalk wrote:
> I was  going to   do the make an offer  for   $1
> alas... no USA shipping it  says!
>
> Sorry, this item cannot be posted to United States.
> You  are unable to bid on or buy this item because:
>  *   The  seller has specified that this item cannot be sent to
> addresses in United  States
>
>
> Ed#
>
>
> In a message dated 8/18/2017 7:25:05 P.M. US Mountain Standard Time,
> cctalk@classiccmp.org writes:
>
> And the bidding has  gone wild!
>
>
My favorite was a pair of "Les Paul" capacitors for roughly
$75 USD each.  These were USED oil-paper capacitors that
looked like they came from the 1950's or 60's.  Black
tubular with color code stripes, and leads about 1/4" long.

Jon

Re: This Is Such An Exciting Listing!

[Jon Elson via cctalk]

On 08/18/2017 09:32 PM, Ed via cctalk wrote:

I was  going to   do the make an offer  for   $1
alas... no USA shipping it  says!
  
Sorry, this item cannot be posted to United States.

You  are unable to bid on or buy this item because:
 *   The  seller has specified that this item cannot be sent to
addresses in United  States
  
  
Ed#
  
  
In a message dated 8/18/2017 7:25:05 P.M. US Mountain Standard Time,

cctalk@classiccmp.org writes:

And the bidding has  gone wild!


My favorite was a pair of "Les Paul" capacitors for roughly 
$75 USD each.  These were USED oil-paper capacitors that 
looked like they came from the 1950's or 60's.  Black 
tubular with color code stripes, and leads about 1/4" long.


Jon

Re: This Is Such An Exciting Listing!

[Ed via cctalk]

I was  going to   do the make an offer  for   $1
alas... no USA shipping it  says!
 
Sorry, this item cannot be posted to United States. 
You  are unable to bid on or buy this item because:
*   The  seller has specified that this item cannot be sent to 
addresses in United  States
 
 
Ed#
 
 
In a message dated 8/18/2017 7:25:05 P.M. US Mountain Standard Time,  
cctalk@classiccmp.org writes:

And the bidding has  gone wild!

Dwight



From:  cctalk  on behalf of Rob Jarratt via  
cctalk 
Sent: Friday, August 18, 2017 4:13:56  PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: This Is  Such An Exciting  Listing!

http://www.ebay.co.uk/itm/182707649701

Re: This Is Such An Exciting Listing!

[dwight via cctalk]

And the bidding has gone wild!

Dwight



From: cctalk  on behalf of Rob Jarratt via 
cctalk 
Sent: Friday, August 18, 2017 4:13:56 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: This Is Such An Exciting Listing!

http://www.ebay.co.uk/itm/182707649701

Re: This Is Such An Exciting Listing!

[Pete Turnbull via cctalk]

On 19/08/2017 00:46, Adrian Graham via cctalk wrote:

It doesn’t beat a listing from 15 or so years ago from a mate of mine who 
advertised a polo mint (lifesavers to our US types) in a clear case as ‘mint in 
box (mint, in box)'


Who remembers the sale of the air guitar?

--
Pete
Pete Turnbull

Re: This Is Such An Exciting Listing!

[Adrian Graham via cctalk]

> On 19 Aug 2017, at 00:13, Rob Jarratt via cctalk  
> wrote:
> 
> http://www.ebay.co.uk/itm/182707649701
> 
> 
> 

It doesn’t beat a listing from 15 or so years ago from a mate of mine who 
advertised a polo mint (lifesavers to our US types) in a clear case as ‘mint in 
box (mint, in box)'


—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: This Is Such An Exciting Listing!

[Fred Cisin via cctalk]

On 2017-08-18 7:13 PM, Rob Jarratt via cctalk wrote:

http://www.ebay.co.uk/itm/182707649701


He won't ship to USA

Re: This Is Such An Exciting Listing!

[Toby Thain via cctalk]

On 2017-08-18 7:13 PM, Rob Jarratt via cctalk wrote:

http://www.ebay.co.uk/itm/182707649701






First time I've seen ebay used for trolling before -- I must live a 
sheltered existence...


A-1 would click to zoom again

--Toby

This Is Such An Exciting Listing!

[Rob Jarratt via cctalk]

http://www.ebay.co.uk/itm/182707649701

 

Re: DCC-116 E / DATA GENERAL NOVA 2/10 / Nixdorf 620 - Restoring and restarting

[Tapley, Mark via cctalk]

Dominique, 
I agree with Rod’s suggestion to check the current, but one other 
possibility is to check for small resistances, maybe considerably less than 1 
Ohm, somewhere between the 5V regulation and the delivery of 5V to the logic 
boards. If a connector  has corroded or a solder joint has developed a crack, 
there could be such a resistance. Then the regulator would actually be 
controlling the output to 5V but the logic boards would only be getting 4V, 3V, 
 etc. off of the bus. The difference would scale with the number of boards in 
the way you describe. 
Hope this helps, apologies if you have already looked at this.
- Mark
210-522-6025 office 
210-379-4635cell



On Aug 18, 2017, at 12:25 PM, Dominique Carlier via cctalk 
 wrote:

> Some news !
> 
> Following a risky way (but I did not see how to do otherwise), I deactivated 
> the Power Fail by hiding the contact number 23 of the two power supplies.
> The idea was to avoid automatic protection by lowering the regulated voltages 
> (+5V and 15V) and see first which unit was involved (G1 or G2), and also 
> which voltages became weak, at what level it is lowered, and according to 
> which board (model or number of connected boards).
> 
> Results of the observations:
> - This is definitely the regulated +5V of the G2 power supply. More I add 
> boards more the + 5v level goes down. +5v, +4.8v, +3.6v, +2.9v. It remains 
> stable however with just the CPU and the three core memory boards, it becomes 
> difficult for the power supply when I add boards in addition to these.
> - This is definitely not a problem at the level of the Power Fail circuit.
> - The big capacitors are not in fault (I rechecked twice).
> - So this maybe a problem at the level of the regulation itself, the +5V 
> balancing system ?
> 
> Question: a faulty voltage regulator can behave in this way? I always thought 
> it worked or it did not work, but not between the two states depending on the 
> charge.
> 
> Anyway, suggestions are always welcome ;-)
> 
> PS : I'm starting to want to put another power supply for that regulated +5V, 
> and bypass the +5V regulated of G2, but it would be a shame and not in the 
> spirit of a restoration in my opinion.

Re: DCC-116 E / DATA GENERAL NOVA 2/10 / Nixdorf 620 - Restoring and restarting

[Rod Smallwood via cctalk]

Check the current



On 18/08/2017 18:25, Dominique Carlier via cctalk wrote:

Some news !

Following a risky way (but I did not see how to do otherwise), I 
deactivated the Power Fail by hiding the contact number 23 of the two 
power supplies.
The idea was to avoid automatic protection by lowering the regulated 
voltages (+5V and 15V) and see first which unit was involved (G1 or 
G2), and also which voltages became weak, at what level it is lowered, 
and according to which board (model or number of connected boards).


Results of the observations:
- This is definitely the regulated +5V of the G2 power supply. More I 
add boards more the + 5v level goes down. +5v, +4.8v, +3.6v, +2.9v. It 
remains stable however with just the CPU and the three core memory 
boards, it becomes difficult for the power supply when I add boards in 
addition to these.
- This is definitely not a problem at the level of the Power Fail 
circuit.

- The big capacitors are not in fault (I rechecked twice).
- So this maybe a problem at the level of the regulation itself, the 
+5V balancing system ?


Question: a faulty voltage regulator can behave in this way? I always 
thought it worked or it did not work, but not between the two states 
depending on the charge.


Anyway, suggestions are always welcome ;-)

PS : I'm starting to want to put another power supply for that 
regulated +5V, and bypass the +5V regulated of G2, but it would be a 
shame and not in the spirit of a restoration in my opinion.





 Forwarded Message 
Subject: Re: DCC-116 E / DATA GENERAL NOVA 2/10 / Nixdorf 620 - 
Restoring and restarting

Date: Wed, 16 Aug 2017 23:33:31 +0200
From: Dominique Carlier 
To: Christian Kennedy via cctalk 



Hi !

I finally find some time to work again on my D-116, try to find the
problem(s), thus principally at the level of PSUs.
As you suggested, I inspected particularly the large capacitors of both
power supplies. I replaced those that appeared suspicious according to
the results via my ESR meter, but note that this one is not supposed to
be able to verify the capacitors of more than 22000μF. I have also some
doubt about the results (capacitor working with a real charge or not).

Anyway, unfortunately the problem is still there. I don't know where to
search now. If I understand well, the two power supplies can cause a
Power Fail if one of the regulated voltages were out of range. At this
point I do not know which of the two is in fault, because when the Power
Fail is active the + 5V is automatically dropped around 1.5V.
Following the schematics I have focused my attention on the value of
some resistors with an important role in triggering this state (eg R18).
I found nothing abnormal, I checked all the capacitors, a large package
of resistances.

At this point what I know is that I can simultaneously connect the CPU
board and the three core memory boards without problem. If I add the
controller board for the removable hard disk drive or for the tape ->
Power Fail.
Interesting thing: if I connect only the CPU board and the disk
controller: Power Fail too. Maybe the PSU in default is the one that
supply the + 5V for the boards in the upper part of the rack? (slot 1
for the CPU, solt 4, 5 and 7 for the mem, slot 10 and 12 for tape and 
hdd)


I can provide pictures, schematics, ...

Regardless of this failure, I try to find information about what I could
install as an operating system on that big beast. If you have too any
ideas about that?

I would like to be able to do simple tasks such as managing files
(copying files from disk to tape and vice versa), being able to create
directories and sub directories, writing text, print on my drum printer,
programming in a simple language such as BASIC, and also, if I find a
communication board (on the CPU-board I don't found any trace of
components that evoke me an RS-232 interface), communicate with another
machine, print on a teletype ... Does this seem possible for you with
this type of machine? If yes, with which OS?

I took tons of pictures of the machine from all angles, I will post them
soon ;-)

Dominique




If I removes all the boards (printer, core memory, scanner, disk
controller, etc.), the Power Fail light eventually goes out, I get 
again

the 5VDC, so the power has become "too weak" to power the computer when
it is fully populated.

It's a switcher; look at the caps in the LC filter (downstream of the
series pass transistor) that, together with the inductor, form the
energy storage mechanism of the power supply; check the source supply as
well.  The fact that it eventually comes back suggests that the
reference, comparator and pass device are probably functioning.




--
Wanted one pdp-8/i rocker switch leaver to copy.

Re: DCC-116 E / DATA GENERAL NOVA 2/10 / Nixdorf 620 - Restoring and restarting

[Dominique Carlier via cctalk]

Some news !

Following a risky way (but I did not see how to do otherwise), I 
deactivated the Power Fail by hiding the contact number 23 of the two 
power supplies.
The idea was to avoid automatic protection by lowering the regulated 
voltages (+5V and 15V) and see first which unit was involved (G1 or G2), 
and also which voltages became weak, at what level it is lowered, and 
according to which board (model or number of connected boards).


Results of the observations:
- This is definitely the regulated +5V of the G2 power supply. More I 
add boards more the + 5v level goes down. +5v, +4.8v, +3.6v, +2.9v. It 
remains stable however with just the CPU and the three core memory 
boards, it becomes difficult for the power supply when I add boards in 
addition to these.

- This is definitely not a problem at the level of the Power Fail circuit.
- The big capacitors are not in fault (I rechecked twice).
- So this maybe a problem at the level of the regulation itself, the +5V 
balancing system ?


Question: a faulty voltage regulator can behave in this way? I always 
thought it worked or it did not work, but not between the two states 
depending on the charge.


Anyway, suggestions are always welcome ;-)

PS : I'm starting to want to put another power supply for that regulated 
+5V, and bypass the +5V regulated of G2, but it would be a shame and not 
in the spirit of a restoration in my opinion.





 Forwarded Message 
Subject: 	Re: DCC-116 E / DATA GENERAL NOVA 2/10 / Nixdorf 620 - 
Restoring and restarting

Date:   Wed, 16 Aug 2017 23:33:31 +0200
From:   Dominique Carlier 
To: Christian Kennedy via cctalk 



Hi !

I finally find some time to work again on my D-116, try to find the
problem(s), thus principally at the level of PSUs.
As you suggested, I inspected particularly the large capacitors of both
power supplies. I replaced those that appeared suspicious according to
the results via my ESR meter, but note that this one is not supposed to
be able to verify the capacitors of more than 22000μF. I have also some
doubt about the results (capacitor working with a real charge or not).

Anyway, unfortunately the problem is still there. I don't know where to
search now. If I understand well, the two power supplies can cause a
Power Fail if one of the regulated voltages were out of range. At this
point I do not know which of the two is in fault, because when the Power
Fail is active the + 5V is automatically dropped around 1.5V.
Following the schematics I have focused my attention on the value of
some resistors with an important role in triggering this state (eg R18).
I found nothing abnormal, I checked all the capacitors, a large package
of resistances.

At this point what I know is that I can simultaneously connect the CPU
board and the three core memory boards without problem. If I add the
controller board for the removable hard disk drive or for the tape ->
Power Fail.
Interesting thing: if I connect only the CPU board and the disk
controller: Power Fail too. Maybe the PSU in default is the one that
supply the + 5V for the boards in the upper part of the rack? (slot 1
for the CPU, solt 4, 5 and 7 for the mem, slot 10 and 12 for tape and hdd)

I can provide pictures, schematics, ...

Regardless of this failure, I try to find information about what I could
install as an operating system on that big beast. If you have too any
ideas about that?

I would like to be able to do simple tasks such as managing files
(copying files from disk to tape and vice versa), being able to create
directories and sub directories, writing text, print on my drum printer,
programming in a simple language such as BASIC, and also, if I find a
communication board (on the CPU-board I don't found any trace of
components that evoke me an RS-232 interface), communicate with another
machine, print on a teletype ... Does this seem possible for you with
this type of machine? If yes, with which OS?

I took tons of pictures of the machine from all angles, I will post them
soon ;-)

Dominique




If I removes all the boards (printer, core memory, scanner, disk
controller, etc.), the Power Fail light eventually goes out, I get again
the 5VDC, so the power has become "too weak" to power the computer when
it is fully populated.

It's a switcher; look at the caps in the LC filter (downstream of the
series pass transistor) that, together with the inductor, form the
energy storage mechanism of the power supply; check the source supply as
well.  The fact that it eventually comes back suggests that the
reference, comparator and pass device are probably functioning.

Re: Vintage equipment rack?

[Ed via cctalk]

Anders - 
 
Your recycler or a scrap yard is a great  place to  look. 
you can try surplus electronic  store also, but unless they  get  burdened  
 with a lot of them  your scrappers at the  end of  the food chain  will be 
the most reasonable as a general rule.
 
Ed#  _www.smecc.org_ (http://www.smecc.org)  
 
 
 
 
 
 
 
In a message dated 8/18/2017 9:29:50 A.M. US Mountain Standard Time,  
cctalk@classiccmp.org writes:

Hey  all,

Does anyone know of a source around NYC (or within a few hours  driving
distance) for a vintage or otherwise interesting, affordable  equipment
rack? I have a space in my living room where I'd like to place an  old
Systron Donner frequency counter, a Remex paper tape reader and  a
reproduction PDP-8/e switch panel (thanks Rod). Aside from those items,  the
rest of the rack would serve as a bookshelf.

I've seen some  racks on eBay (including a Norelco computing stack) but most
are too far  away or expensive (>$200). I have't yet checked scrap yards or
e-waste  recyclers.

Any ideas would be appreciated!

--
Anders  Nelson

+1 (517)  775-6129

www.erogear.com

Vintage equipment rack?

[Anders Nelson via cctalk]

Hey all,

Does anyone know of a source around NYC (or within a few hours driving
distance) for a vintage or otherwise interesting, affordable equipment
rack? I have a space in my living room where I'd like to place an old
Systron Donner frequency counter, a Remex paper tape reader and a
reproduction PDP-8/e switch panel (thanks Rod). Aside from those items, the
rest of the rack would serve as a bookshelf.

I've seen some racks on eBay (including a Norelco computing stack) but most
are too far away or expensive (>$200). I have't yet checked scrap yards or
e-waste recyclers.

Any ideas would be appreciated!

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com

Re: RX01 and RL01 on same UNIBUS system

[Jon Elson via cctalk]

On 08/17/2017 03:48 PM, william degnan via cctalk wrote:

Just curious,
Is there anyone out there with a combo RX01 and RL01 on the same UNIBUS
system, today?  Are there any known issues?
As long as you set different CSR and interrupt vectors for 
the two devices, they have to work fine.
Possibly some boot ROMs might not set this up right, but you 
can always toggle in a boot program that handles it.


Jon

Re: Service manual for IBM PS/2 Monochrome Display?

[Richard Sheppard via cctalk]

The Technical Reference for the original IBM PC has schematics - "Logic 
Diagrams" in the appendices, including the monochrome monitor. That pre-dates 
the PS2s of course but they may be similar. Usual cautions about discharging 
the anode on the CRT before you poke around in there.

Richard

Champaign, IL to Iowa City, Iowa and back trip

[Paul Anderson via cctalk]

I'll be going to Iowa City, Iowa on Tuesday, 29 AUG and returning to
Champaign, IL on late Wednesday, 30 AUG.

If anyone needs anything moved feel free to contact me. If it is along the
interstate and not too big, there is no charge. I might have less space on
the return trip. I can possible store items for a while.

Paul