Re: Straight 8 up on Ebay just now

[COURYHOUSE]

agreed.
 
if it would have been 11/20 and a h960  would have been   muccc more 
reasonable..
 
 
what was there was totally amazing.
 
Ed#
 
 
In a message dated 7/24/2016 9:05:37 P.M. US Mountain Standard Time,  
j...@mercury.lcs.mit.edu writes:

> From: Glen Slick

> For the curious about  the eBay market value of the PDP-11/20 today

That one was a  once-in-a-lifetime thing, though: not only a KA11 in
absolutely pristine  condition, but also an additional BA11 stuffed to the
gills with memory;  the most complete set of original documentation I have
_ever_ seen with a  computer that old; a complete H960 in perfect condition,
with all the blank  panels, the rear door, etc; trays and trays of original
paper tape  software, etc, etc.

When you consider that that PDP-11/70 that went a  while back for $10K - and
-11/70's are a lot more common that -11/20's - I  think this one was easily
worth what it went for.

I'm quite serious  - I doubt we'll ever see another -11/20 in this good a
shape, and this  complete, for sale, at least, not in my remaining lifetime.

Noel

Re: memory map for RT-11 v 5

[Don North]

On 7/24/2016 2:37 PM, Paul Koning wrote:

On Jul 24, 2016, at 11:06 AM, william degnan  wrote:


...
Attempts to boot from RT11SJ.SYS under V04.00 of RT-11 with 24K
bytes of memory were successful.  Attempts to boot with 16K bytes of
memory were also successful.  An RK05 was used as the disk drive.  The
error message "Insufficient memory" is displayed, but some useful work
might be done with just 16K bytes of memory. However, you did not
ask if useful work being done was one of the criteria?

FWIW, I used to run RT11SJ on an 11/20 with 8 kW (16 kB) of memory and RC11 
system disk, in college.  That fit with no trouble, enough room to run RT BASIC 
and a reasonably application program.

paul



And it still works today:

PDP-11 simulator V4.0-0 Betagit commit id: 4065f47f
sim> set cpu 11/05 16k
sim> sho cpu
CPU 11/05, idle disabled, autoconfiguration enabled
16KB
sim> att rk0 rt11.dsk
sim> boot rk0

RT-11SJV02C-02

.
.R PIP
*/L

DTMNSJ.SYS   46 27-NOV-75
DTMNFB.SYS   58 27-NOV-75
DP.SYS2 27-NOV-75
RK.SYS2 27-NOV-75
RF.SYS2 27-NOV-75
TT.SYS2 27-NOV-75
LP.SYS2 27-NOV-75
BA.SYS7 27-NOV-75
SYSMAC.SML   18 27-NOV-75
SYSMAC.8K25 27-NOV-75
BATCH .SAV   25 27-NOV-75
EDIT  .SAV   19 27-NOV-75
MACRO .SAV   31 27-NOV-75
ASEMBL.SAV   21 27-NOV-75
EXPAND.SAV   12 27-NOV-75
CREF  .SAV5 27-NOV-75
LINK  .SAV   25 27-NOV-75
PIP   .SAV   14 27-NOV-75
PATCH .SAV5 27-NOV-75
ODT   .OBJ9 27-NOV-75
VTHDLR.OBJ8 27-NOV-75
DEMOFG.MAC5 27-NOV-75
DEMOBG.MAC4 27-NOV-75
KB.MAC   33 27-NOV-75
LIBR  .SAV   15 27-NOV-75
MONITR.SYS   46 27-NOV-75
RKMNFB.SYS   58 27-NOV-75
RFMNSJ.SYS   46 27-NOV-75
RFMNFB.SYS   58 27-NOV-75
DPMNSJ.SYS   46 27-NOV-75
DPMNFB.SYS   58 27-NOV-75
DXMNSJ.SYS   46 27-NOV-75
DXMNFB.SYS   58 27-NOV-75
DT.SYS2 27-NOV-75
DX.SYS2 27-NOV-75
CR.SYS3 27-NOV-75
MT.SYS6 27-NOV-75
MM.SYS6 27-NOV-75
PR.SYS2 27-NOV-75
PP.SYS2 27-NOV-75
CT.SYS5 27-NOV-75
DS.SYS2 27-NOV-75
FILEX .SAV   11 27-NOV-75
SRCCOM.SAV   11 27-NOV-75
DUMP  .SAV5 27-NOV-75
PATCHO.SAV   33 27-NOV-75
VTMAC .MAC7 27-NOV-75
SYSF4 .OBJ   33 27-NOV-75
BASIC .SAV   36
BAS8K .SAV   34
DEMO  .BAS3
51 FILES, 1014 BLOCKS
3760 FREE BLOCKS
*
.
.R BAS8K

BASIC V01B-02
*

READY

OLD
OLD FILE NAME--DEMO

READY

LIST

DEMO   BASIC V01B-02

10 REM BASIC PROGRAM TO GENERATE N TERMS OF A FIBONACCI SERIES,
20 REM THE FIRST TWO TERMS OF WHICH ARE SPECIFIED BY THE USER.
30 REM
40 REM PRINT IDENTIFYING MESSAGE
50 PRINT "PROGRAM TO GENERATE A FIBONACCI SERIES"
60 REM
70 REM GET THE LENGTH AND FIRST TWO TERMS OF THE SERIES
80 PRINT "HOW MANY TERMS DO YOU WANT GENERATED";
90 INPUT L
100 IF L<>0 THEN 130
110 REM IF HE REQUESTS 0 TERMS,TERMINATE EXECUTION
120 STOP
130 PRINT "WHAT IS THE FIRST TERM";
140 INPUT T1
150 PRINT "WHAT IS THE SECOND TERM";
160 INPUT T2
170 REM MAKE SURE L IS NOT NEGATIVE OR TOO LARGE
180 IF L<3 THEN 200
190 IF L<50 THEN 220
200 PRINT L;"TERMS DOES NOT REALLY MAKE SENSE."
210 GO TO 80
220 REM PRINT THE FIRST TWO TERMS OF THE SERIES
230 PRINT "THE REQUESTED SERIES IS"
240 PRINT T1
250 PRINT T2
260 L=L-2
270 REM CALCULATE NEXT TERM AND PRINT IT
280 N=T1+T2
290 T1=T2
300 T2=N
310 PRINT N
320 REM DETERMINE IF SERIES IS FINISHED. IF SO,DO NEXT ONE.
330 L=L-1
340 IF L<=0 THEN 80
350 GO TO 280
360 END

READY

RUN

DEMO   BASIC V01B-02

PROGRAM TO GENERATE A FIBONACCI SERIES
HOW MANY TERMS DO YOU WANT GENERATED?4
WHAT IS THE FIRST TERM?12
WHAT IS THE SECOND TERM?5
THE REQUESTED SERIES IS
 12
 5
 17
 22
HOW MANY TERMS DO YOU WANT GENERATED?0

STOP AT LINE 120

READY

Re: memory map for RT-11 v 5

[Paul Koning]

> On Jul 24, 2016, at 11:06 AM, william degnan  wrote:
> 
>> ...
>> Attempts to boot from RT11SJ.SYS under V04.00 of RT-11 with 24K
>> bytes of memory were successful.  Attempts to boot with 16K bytes of
>> memory were also successful.  An RK05 was used as the disk drive.  The
>> error message "Insufficient memory" is displayed, but some useful work
>> might be done with just 16K bytes of memory. However, you did not
>> ask if useful work being done was one of the criteria?

FWIW, I used to run RT11SJ on an 11/20 with 8 kW (16 kB) of memory and RC11 
system disk, in college.  That fit with no trouble, enough room to run RT BASIC 
and a reasonably application program.

paul

Re: memory map for RT-11 v 5

[j...@cimmeri.com]

On 7/24/2016 10:06 AM, william degnan 
wrote:

...

One thing to remember is 16KW in a pdp11 is not the same thing that simh
refers to when one sets the CPU to 16K.  WWW do not all make this
distinction clearly.  I get it, just making this comment for future readers
of this thread.

Bill



What is the distinction?

- J.

Re: Signetics N8251 source?

[Karl-Wilhelm Wacker]

I have looked at the pinout, it is different, but you can use a method 
called "dead-bug"

to wire the 7442 in place of the n8251.

I've attached the spec sheet for the n8251 to this email.

Karl

- Original Message - 
From: "Karl-Wilhelm Wacker" 
To: "General Discussion: On-Topic and Off-Topic Posts" 


Sent: Sunday, July 24, 2016 1:13 PM
Subject: Re: Signetics N8251 source?



Mattis:

 By the description, it is a 1 of 10 decoder chip.

 Have you looked to see if it pinout compatable
with a 7442?

Karl

- Original Message - 
From: "Mattis Lind" 
To: "General Discussion: On-Topic and Off-Topic Posts" 


Sent: Sunday, July 24, 2016 5:01 AM
Subject: Signetics N8251 source?


After successfully repairing the G231 module of the MM11-L set I 
continued

with the next one. This one was not able to access addresses ending 0100
(binary). Luckily it was not the transistors arrays that were bad but the
selector chip. A Signetics N8251 chip.

I found a source on ebay at $4.95 each plus $13 shipping. A little bit to
much for my taste (although I could make an offer)

Anyone know of a cheaper source? I could use five or ten maybe.

/Mattis

Re: seeking DEC VAXmate software

[Camiel Vanderhoeven]

> Is the bulk of the computer in the monitor and the box it stands on "just"
> an ISA expansion, PSU and hard disk?

Yes, it's an optional expansion box. The idea behind the vaxmate was that
instead of from a hard disk, it could run from a disk image on a VAX, so a
local hard disk was optional.

Camiel

Re: memory map for RT-11 v 5

[william degnan]

On Jul 24, 2016 8:58 AM, "Jerome H. Fine"  wrote:
>
> >On Wednesday, July 20th, 2016 at 18:02:44 - 0400, william degnan wrote:
>
>> Is there a minimum memory requirement for RT-11 v5?  I was discussing
with
>> Ray Fantini about it today, unsure...anyone know if 16K will work (from
>> 00).
>>
>> Bill
>>
> You need to be more specific!  Starting with V05.00 of RT-11 in 1983,
> there were a total of 17 versions released up to V05.07 in 1998, including
> sub-versions V05.01B, V05.01C, and V05.04A to V05.04G of RT-11.
>
> Up until V05.05 of RT-11, RT11SJ.SYS required the least memory which
> was replaced with RT11SB.SYS for V05.06 and V05.07 of RT-11.
>
> Attempts to boot from RT11SJ.SYS under V05.00 of RT-11 with 24K
> bytes of memory were successful.  Attempts to boot with 16K bytes of
> memory were unsuccessful.  An RK05 was used as the disk drive since
> it is close to the smallest device driver.  The answer to your question
about
> using 16K bytes of memory is NO for all versions of RT-11 starting with
> V05.00 or RT-11.
>
> Attempts to boot from RT11SJ.SYS under V04.00 of RT-11 with 24K
> bytes of memory were successful.  Attempts to boot with 16K bytes of
> memory were also successful.  An RK05 was used as the disk drive.  The
> error message "Insufficient memory" is displayed, but some useful work
> might be done with just 16K bytes of memory. However, you did not
> ask if useful work being done was one of the criteria?
>
> NOTE that I used the Ersatz-11 emulator to check the above details,
> so there might be a difference with actual hardware.
>
> If you have any more questions, please ask.
>
> Jerome Fine

Thanks for the details.  I had been trying to boot rt-11 v5.3 on a 16k core
11/40 using RL11 (rl02) and it did not work.   The system was unable to
complete the initialization.  CPU diagnostics passed, I could load BASIC
papertape.  RL11 working correctly.  In this context I posted my question.

After I posted my message here I loaded up simh and emulated an 11 with
32k.  RT-11 v5.3 disk boots.  When I re-built the system and reduced to
16k, I could not boot, bombed.

One thing to remember is 16KW in a pdp11 is not the same thing that simh
refers to when one sets the CPU to 16K.  WWW do not all make this
distinction clearly.  I get it, just making this comment for future readers
of this thread.

Bill

Re: Straight 8 up on Ebay just now

[ben]

On 7/24/2016 9:50 PM, Mark Linimon wrote:

On Sun, Jul 24, 2016 at 08:08:53PM -0700, Glen Slick wrote:

For the curious about the eBay market value of the PDP-11/20 today, it
just sold for $5,655.55


well, there goes that fantasy.

mcl


Well in 1972 you could get ...
 http://www.village.org/pdp-11/faq.pages/pricing.pdp11-05-15-apr-1972.html
 Too bad I/O other than TTY is not listed.
 Ben.

Re: Straight 8 up on Ebay just now

[Noel Chiappa]

> From: Glen Slick

> For the curious about the eBay market value of the PDP-11/20 today

That one was a once-in-a-lifetime thing, though: not only a KA11 in
absolutely pristine condition, but also an additional BA11 stuffed to the
gills with memory; the most complete set of original documentation I have
_ever_ seen with a computer that old; a complete H960 in perfect condition,
with all the blank panels, the rear door, etc; trays and trays of original
paper tape software, etc, etc.

When you consider that that PDP-11/70 that went a while back for $10K - and
-11/70's are a lot more common that -11/20's - I think this one was easily
worth what it went for.

I'm quite serious - I doubt we'll ever see another -11/20 in this good a
shape, and this complete, for sale, at least, not in my remaining lifetime.

Noel

Re: Straight 8 up on Ebay just now

[Adrian Stoness]

buyer aranges pick prolly hurt the price as well


On Sun, Jul 24, 2016 at 10:50 PM, Mark Linimon  wrote:

> On Sun, Jul 24, 2016 at 08:08:53PM -0700, Glen Slick wrote:
> > For the curious about the eBay market value of the PDP-11/20 today, it
> > just sold for $5,655.55
>
> well, there goes that fantasy.
>
> mcl
>

Re: Straight 8 up on Ebay just now

[Mark Linimon]

On Sun, Jul 24, 2016 at 08:08:53PM -0700, Glen Slick wrote:
> For the curious about the eBay market value of the PDP-11/20 today, it
> just sold for $5,655.55

well, there goes that fantasy.

mcl

Re: Straight 8 up on Ebay just now

[couryhouse]

Think it was add on box that went for the $! ---Ed#


Sent from my Verizon, Samsung Galaxy smartphone

 Original message 
From: Glen Slick  
Date: 7/24/16  20:08  (GMT-07:00) 
To: "General Discussion: On-Topic and Off-Topic Posts"  
Subject: Re: Straight 8 up on Ebay just now 

>
> Straight PDP-8
> http://www.ebay.com/itm/152171436497
>
> PDP-11/20
> http://www.ebay.com/itm/201624309371

For the curious about the eBay market value of the PDP-11/20 today, it
just sold for $5,655.55

Re: Straight 8 up on Ebay just now

[Glen Slick]

>
> Straight PDP-8
> http://www.ebay.com/itm/152171436497
>
> PDP-11/20
> http://www.ebay.com/itm/201624309371

For the curious about the eBay market value of the PDP-11/20 today, it
just sold for $5,655.55

Re: Signetics N8251 source?

[Brian Walenz]

On Sun, Jul 24, 2016 at 5:01 AM, Mattis Lind  wrote:

> After successfully repairing the G231 module of the MM11-L set I continued
> with the next one. This one was not able to access addresses ending 0100
> (binary). Luckily it was not the transistors arrays that were bad but the
> selector chip. A Signetics N8251 chip.
>

I suspect that since you've debugged it already, this won't help.  Just in
case,
the datasheet is on page 52 of:

https://archive.org/details/bitsavers_signeticsdcs8000SeriesTTLMSI_11847693

/Mattis
>

b

RE: GE Canada are hiring... A PDP-11 programmer

[Ali]

> Yes, today.
> 
> http://www.vcfed.org/forum/showthread.php?37827-Greetings-from-GE-
> Canada!=c5a7c6993a9fd08879d7e412fdd31010


Huh? That post is over three years old. Am I missing something?

Re: GE Canada are hiring... A PDP-11 programmer

[Adrian Stoness]

glad to hear they are moving forward with this wish i had the skills im
just a nooby

On Sun, Jul 24, 2016 at 7:01 PM, Liam Proven  wrote:

> Yes, today.
>
>
> http://www.vcfed.org/forum/showthread.php?37827-Greetings-from-GE-Canada!=c5a7c6993a9fd08879d7e412fdd31010
>
> --
> Sent from my phone - please pardon brevity & typos.
>

GE Canada are hiring... A PDP-11 programmer

[Liam Proven]

Yes, today.

http://www.vcfed.org/forum/showthread.php?37827-Greetings-from-GE-Canada!=c5a7c6993a9fd08879d7e412fdd31010

-- 
Sent from my phone - please pardon brevity & typos.

Re: FTGH: DEC 54-17507 backplane; Sun type-4 keyboards

[Mouse]

>> - One DEC 54-17507.  Google makes me think this is the Qbus
>>backplane from a BA123.  [...]
> Did you find a home for this yet?

Yes, though it depends on figuring out a place/time to meet the
recipient when on a trip I'm going to be making in mid-August.  If that
falls through (which currently looks unlikely), then it'll be looking
for a home.

/~\ 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: Signetics N8251 source?

[Karl-Wilhelm Wacker]

Mattis:

 By the description, it is a 1 of 10 decoder chip.

 Have you looked to see if it pinout compatable
with a 7442?

Karl

- Original Message - 
From: "Mattis Lind" 
To: "General Discussion: On-Topic and Off-Topic Posts" 


Sent: Sunday, July 24, 2016 5:01 AM
Subject: Signetics N8251 source?



After successfully repairing the G231 module of the MM11-L set I continued
with the next one. This one was not able to access addresses ending 0100
(binary). Luckily it was not the transistors arrays that were bad but the
selector chip. A Signetics N8251 chip.

I found a source on ebay at $4.95 each plus $13 shipping. A little bit to
much for my taste (although I could make an offer)

Anyone know of a cheaper source? I could use five or ten maybe.

/Mattis 

ISO Televideo 965 eprom images

[Al Kossow]

I was digging around in storage and found a 965 board that is missing 
its eproms. Does anyone have one handy that they could dump the proms from?


It's kind of unusual in that it uses a 65816 cpu. Seems to be a midway
design between the earlier 6502's and the later 68000's.

Re: FTGH: DEC 54-17507 backplane; Sun type-4 keyboards

[Jules Richardson]

On 07/13/2016 07:58 PM, Mouse wrote:

- One DEC 54-17507.  Google makes me think this is the Qbus backplane
from a BA123.  It appears to be in good shape; while I am not set up
to test it, it looks pretty much "too simple to break".  It consists
of the PCB, the Qbus connectors on one side, two 18-pin power
connectors and one ten-pin connector with blue plastic shroud on the
other side, and a piece of heavy sheet steel all this is bolted to.
(And the bolts, of course. :-)  Oh, all four resistor packs are
installed.


Did you find a home for this yet? I'm tempted, just because it might be 
what I need to try powering up the 11/84 CPU that I got in my recent pile 
of DEC boards.


cheers

Jules

Re: KT-24 and/or -11/24 backplane info

[Noel Chiappa]

> Guess I should document all this in the Computer History Wiki

OK, done:

  http://gunkies.org/wiki/PDP-11/24

> those prints (KT-24, and -11/24 backplane) would still be useful.

Big thanks for Al for putting the KT24 prints up - very good to have them.

> I guess it will require getting ahold of a backplane, and seeing what I
> can find out with an ohm-meter.

It looks like I'll still have to do this at some point, to confirm my
theories about how the two busses are wired on the backplane (separation of
UB and EUB address lines, and cross-connection of the data lines, for the
EUB/SPC slots), since we still don't have any backplane info.


Another mystery: The "PDP-11 UNIBUS Processor Handbook" (1985) says (pg. 4-10)
that in the 5.25" box, "only one MS11-P memory module can be
configured". Anyone know the cause/source of that restriction?

I don't think it can be the backplane; i) AFAIK, the 5.25" and 10.5" (for
which no limitation is stated) boxes use the same backplane, and ii) the 5.25"
box can take more of the smaller MS11-L cards (albeit, again, limited - to
three). So I don't think it can be 'the backplane doesn't carry all 22 address
lines to all EUB slots' (although I will check); and the CPU does drive all
22.

My next thought was that it's some power supply current issue, but on
checking, that board only uses +5V, and there's nothing about limiting the
number of ordinary boards when an MS11-P is in use. (I have to check the power
supply specs, and compare with the board power consumption specs, to make
completely positive there's no issue there.)

So I can't come up with any technical rationale for that limit? Am I missing
something? Or is it just DEC marketing, trying to limit how powerful the
machine can be?

Noel

Re: seeking DEC VAXmate software

[Pontus Pihlgren]

On Sun, Jul 24, 2016 at 05:01:42PM +1000, Nigel Williams wrote:
> I'm on the hunt for diskette images of DEC VAXmate software. From a
> post to comp.sys.dec there appears to be at least the following
> diskettes, but possibly more:
> 
> VAXmate MS-DOS version 3.10 for VAXmate Oper Environ V1.1
> VAXMATE S/A INSTALL V1.1
> VT240 EMULATOR UPDATE For VAXmate Oper Environ V1.1
> VAXMATE INFO. SYSTEM V1.1 FOR VAXMATE OPER ENVIRON V1.1
> VAXMATE MS-WINDOWS V1.03 (three disks)
> 
> If anyone has the diskettes or can point me somewhere to look, it
> would be appreciated.
> thanks.
> 
> Other notes:
> If anyone is desperate to own a VAXmate I can provide contact details
> of someone who has a few.
> 
> Here is my VAXmate running a generic MS-DOS 4.0, the screen is very
> dim, and a few other pictures (as it arrived, so before any cleaning -
> quote dusty inside):
> 
> https://goo.gl/photos/cQkbekoLiWBCZoad9

Thanks for sharing! I can't help you with the software but it's fun to see 
the innards of one of those.

Is the bulk of the computer in the monitor and the box it stands on "just" 
an ISA expansion, PSU and hard disk?

Curious construction.

/P

RE: Nova 3 front panel

[Henk Gooijen]

Van: jim stephens

Re: Flex Disc options for the HP 9825

[curiousmarc3]

Thanks for looking!
Marc

> On Jul 24, 2016, at 3:30 AM, David Collins  wrote:
> 
> Guys, I've looked for a 98228A ROM in the HP Computer Museum but haven't
> been able to find one - but it looks like we've had one at some stage
> judging by the photo. 
> 
> If I come across it I'll come back to you. 
> 
> David Collins 
> Curator
> 
> 
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of CuriousMarc
> Sent: Saturday, 23 July 2016 5:40 PM
> To: 'General Discussion: On-Topic and Off-Topic Posts'
> 
> Subject: RE: Flex Disc options for the HP 9825
> 
> Thanks, I didn't know, I grabbed the image. That offers a path if I can ever
> get an 9885 and single sides 8" discs...
> Marc
> 
>> -Original Message-
>> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Paul 
>> Berger On the hpmuseum.net page for the 98217A ROM here is an image of 
>> what is reputed to be an initialized diskette for use with 9825 and 
>> 98217A http://www.hpmuseum.net/display_item.php?hw=166. When I get my 
>> 9825T I will look into 9885 emulation, I don't think it will be too
> difficult but
>> you may still need a GPIO unless I build the whole thing onto a 
>> plug-in card I don't think the GPIO would be too difficult to clone.
>> But ideally I would still like to get access to a 98228A ROM to dump 
>> and
> clone
>> it, even though it is bank switched it should still be possible.
>> 
>> Paul.
> 
> 

RE: Flex Disc options for the HP 9825

[David Collins]

Guys, I've looked for a 98228A ROM in the HP Computer Museum but haven't
been able to find one - but it looks like we've had one at some stage
judging by the photo. 

If I come across it I'll come back to you. 

David Collins 
Curator


-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of CuriousMarc
Sent: Saturday, 23 July 2016 5:40 PM
To: 'General Discussion: On-Topic and Off-Topic Posts'

Subject: RE: Flex Disc options for the HP 9825

Thanks, I didn't know, I grabbed the image. That offers a path if I can ever
get an 9885 and single sides 8" discs...
Marc

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Paul 
> Berger On the hpmuseum.net page for the 98217A ROM here is an image of 
> what is reputed to be an initialized diskette for use with 9825 and 
> 98217A http://www.hpmuseum.net/display_item.php?hw=166. When I get my 
> 9825T I will look into 9885 emulation, I don't think it will be too
difficult but
> you may still need a GPIO unless I build the whole thing onto a 
> plug-in card I don't think the GPIO would be too difficult to clone.
> But ideally I would still like to get access to a 98228A ROM to dump 
> and
clone
> it, even though it is bank switched it should still be possible.
> 
> Paul.

RE: HP 9845B Model 100 PSU - looking for transformer

[David Collins]

Martin, apologies for taking so long to reply to this - but I have one of
the transformers you are after.

It's in a defective 9845 power supply but I'm happy to extract it from the
supply if you still need one.

Send me an email at cura...@hpmuseum.net and we can work out the details.

Regards, 

David Collins
Curator, HP Computer Museum

-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of
martin.heppe...@dlr.de
Sent: Friday, 3 June 2016 11:26 PM
To: cctalk@classiccmp.org
Subject: HP 9845B Model 100 PSU - looking for transformer

Hi,

I have got a 9845B which has a defective power supply unit - obviously a
very common problem.
After replacing the cracking epoxy capacitors I found that the mains
transformer seems to have a broken input winding.
Maybe someone tried to run it at 220V using the 110V input selector switch.

What I am now looking for is a defective PSU with a good transformer, resp.
just the transformer which may also have been used in other HP devices..

The transformer is located on the PSU mother board between the two large
capacitors.
It has the part number "9100-4037" and the date code "8-81"  printed on it.
It has two input windings and three output windings. Thus the output is a
bit different (one additional winding compared to Tony Duells schematics).

Maybe someone can help?

Martin

Signetics N8251 source?

[Mattis Lind]

After successfully repairing the G231 module of the MM11-L set I continued
with the next one. This one was not able to access addresses ending 0100
(binary). Luckily it was not the transistors arrays that were bad but the
selector chip. A Signetics N8251 chip.

I found a source on ebay at $4.95 each plus $13 shipping. A little bit to
much for my taste (although I could make an offer)

Anyone know of a cheaper source? I could use five or ten maybe.

/Mattis

Re: MM11-L / G231 repair advice?

[Mattis Lind]

>
> Speaking generally, without specific familiarity with these dec modules . .
>
> Writing is performed by driving the X/Y lines in the opposite polarity
> (current direction) than for reading.
>

OK. That explains why the read signal is routed to the driver selection
circuitry. A couple of inverter was connected in parallel here from the
READ signal coming form the G110. But they were all right.

>
> Have you checked whether it affects the entire memory module or some block
> or selection of addresses within the module?
>

It was the entire memory.

>
> If it's a limited set of addresses it may just be an X/Y driver transistor
> for the polarity appropriate to writing.
>
> If it's the entire module, you might look at how the drive polarity
> selection is done for the X/Y drivers,
> somewhere it should trace back to the R/W/restore state sequencing for a
> memory cycle.
> The problem may then be in that polarity selection or the state sequencing.
>
> The inhibit circuitry does just that: inhibits writing (inhibits setting
> the cores to the 'set' or 'written' state),
> so it doesn't sound as much like an inhibit issue, unless it's something
> like the inhibits always being enabled.
>

With a scope I checked the outputs of E2 which is involved in the sequence
logic. And yes, two outputs were floating. Not normal since this was a
74H00. Replacing it with a 74S00 (no 74H00 available) actually made the
module working again! Thanks for the advice!

Yet again it was a plastic NS manufactured chip from 1973 that had failed.

So now the entire 11/05 is working just fine. Next step is the TC11
controller...

/Mattis

seeking DEC VAXmate software

[Nigel Williams]

I'm on the hunt for diskette images of DEC VAXmate software. From a
post to comp.sys.dec there appears to be at least the following
diskettes, but possibly more:

VAXmate MS-DOS version 3.10 for VAXmate Oper Environ V1.1
VAXMATE S/A INSTALL V1.1
VT240 EMULATOR UPDATE For VAXmate Oper Environ V1.1
VAXMATE INFO. SYSTEM V1.1 FOR VAXMATE OPER ENVIRON V1.1
VAXMATE MS-WINDOWS V1.03 (three disks)

If anyone has the diskettes or can point me somewhere to look, it
would be appreciated.
thanks.

Other notes:
If anyone is desperate to own a VAXmate I can provide contact details
of someone who has a few.

Here is my VAXmate running a generic MS-DOS 4.0, the screen is very
dim, and a few other pictures (as it arrived, so before any cleaning -
quote dusty inside):

https://goo.gl/photos/cQkbekoLiWBCZoad9