adding memory to an IBM PS/1 Model 2123

[daniel_lafosse]

Hi there

I am trying to add memory to an IBM PS/1 Model 2123

The IBM PS/1 Model 2123 has 2 MB of non removable RAM and two
connectors for 72-pin SIMMs. From what I have found on the web, it can
handle SIMMs up to 8 MB each, giving a total of (2 * 8) + 2 = 18 MB of
RAM.

I have tried installing Hewlett-Packard 8 MB 72-pin SIMMs in the slots,
but they aren't recognized. When I turn the machine on, it counts
memory till " 02048 KB ". It seems it cannot see memory above 2 MB.

I have the Reference Diskette and I have started it and chosen
"Automatic Configuration" (or Automatische Konfiguration since it's in
German) but it does not help.

Is there something I am doing wrong ?
Do I need special SIMMs ?

Thank you,
Daniel

 

[The Black Wibble]

Hi there

I am trying to add memory to an IBM PS/1 Model 2123

The IBM PS/1 Model 2123 has 2 MB of non removable RAM and two
connectors for 72-pin SIMMs. From what I have found on the web, it can
handle SIMMs up to 8 MB each, giving a total of (2 * 8) + 2 = 18 MB of
RAM.

I have tried installing Hewlett-Packard 8 MB 72-pin SIMMs in the slots,
but they aren't recognized. When I turn the machine on, it counts
memory till " 02048 KB ". It seems it cannot see memory above 2 MB.

I have the Reference Diskette and I have started it and chosen
"Automatic Configuration" (or Automatische Konfiguration since it's in
German) but it does not help.

Is there something I am doing wrong ?
Do I need special SIMMs ?

There is an "Advanced Diagnotics" disk image for the PS/1 2123 located at
http://www.ps-2.org/mirrors/ps2supersite/ under the heading "Miscellanous".

Ye gads... A PS/1. I was still firmly entrenched in camp Amiga for a few
more years after the PS/1 arrived on the scene. If I ever locate an english
version of the Reference Disk I'll email you. PS/2 ones are easy to find.
Not so with the PS/1, unfortunately.

Tony.

 

[The Black Wibble]

[...]

I have tried installing Hewlett-Packard 8 MB 72-pin SIMMs in the slots,
but they aren't recognized. When I turn the machine on, it counts
memory till " 02048 KB ". It seems it cannot see memory above 2 MB.

I have the Reference Diskette and I have started it and chosen
"Automatic Configuration" (or Automatische Konfiguration since it's in
German) but it does not help.

Is this Reference Disk also called the Starter Diskette? The image for the
model 2123 can be found here:
http://ps2supersite.homedns.org/pccbbs/ps1/ (2123strt.exe).

Is there something I am doing wrong ?
Do I need special SIMMs ?

I see that there are 72-pin Fast Page Mode SIMMs, and EDO SIMMs with and
without parity. There are businesses that sell memory specific to the PS/1.
I'm am wondering if you got yours this way or maybe thought any 8MB 72-pin
SIMM would do.

Tony.

 

[daniel_lafosse]

Thanks for your reaction.

I downloaded and wrote the image on a floppy. I booted on it. It is
similar to the "Reference Disk" I already have, although I understand
English much better than German

Anyway I installed my SIMMs, booted on the disk and chose "Change
Configuration". Alas, the "installed memory" field cannot be changed,
while other fields like the type of floppy disk can be changed...

So I'm stuck with the same problem: The PS/1 doesn't "see" the SIMMs I
have installed.

Here's more information on the SIMMs: There's a sticker on it with:
- the HP Logo
- 1818-6838
- 8 MD EDO 60 (2Mx32)
- Reorder D3647-63001

Searching the web for these reference numbers, I found these SIMMS have
the following characteristics:
- 8MB
- EDO
- 60 ns
- 72 pin

Okay, but now what kind of memory do I *need* for my PS/1 model 2123
?

Thank you,
Daniel

 

[The Black Wibble]

Thanks for your reaction.

I downloaded and wrote the image on a floppy. I booted on it. It is
similar to the "Reference Disk" I already have, although I understand
English much better than German

Anyway I installed my SIMMs, booted on the disk and chose "Change
Configuration". Alas, the "installed memory" field cannot be changed,
while other fields like the type of floppy disk can be changed...

So I'm stuck with the same problem: The PS/1 doesn't "see" the SIMMs I
have installed.

Here's more information on the SIMMs: There's a sticker on it with:
- the HP Logo
- 1818-6838
- 8 MD EDO 60 (2Mx32)
- Reorder D3647-63001

Searching the web for these reference numbers, I found these SIMMS have
the following characteristics:
- 8MB
- EDO
- 60 ns
- 72 pin

Okay, but now what kind of memory do I *need* for my PS/1 model 2123

8MB 72-pin, Fast Page Mode, SIMM modules with parity.

http://www.siliconmt.com/solution.html
http://www.memoryx.net/92g7203.html

EDO memory came out in 1995, long after the PS/1.

Tony.

 

[nobody]

Thanks for your reaction.

I downloaded and wrote the image on a floppy. I booted on it. It is
similar to the "Reference Disk" I already have, although I understand
English much better than German

Anyway I installed my SIMMs, booted on the disk and chose "Change
Configuration". Alas, the "installed memory" field cannot be changed,
while other fields like the type of floppy disk can be changed...

So I'm stuck with the same problem: The PS/1 doesn't "see" the SIMMs I
have installed.

Here's more information on the SIMMs: There's a sticker on it with:
- the HP Logo
- 1818-6838
- 8 MD EDO 60 (2Mx32)
- Reorder D3647-63001

Searching the web for these reference numbers, I found these SIMMS have
the following characteristics:
- 8MB
- EDO
- 60 ns
- 72 pin

Okay, but now what kind of memory do I *need* for my PS/1 model 2123
?

Thank you,
Daniel

Please pardon my curiosity, what is the reason you want to resurrect
this dinosaur that I thought was extinct long ago? Even with memory
upgrade, what it can be used for, except for a computing history
museum exhibit? Even high end P3 systems are getting junked these
days because their time has passed...
NNN

 

[Franc Zabkar]

Thanks for your reaction.

I downloaded and wrote the image on a floppy. I booted on it. It is
similar to the "Reference Disk" I already have, although I understand
English much better than German

Anyway I installed my SIMMs, booted on the disk and chose "Change
Configuration". Alas, the "installed memory" field cannot be changed,
while other fields like the type of floppy disk can be changed...

So I'm stuck with the same problem: The PS/1 doesn't "see" the SIMMs I
have installed.

Here's more information on the SIMMs: There's a sticker on it with:
- the HP Logo
- 1818-6838
- 8 MD EDO 60 (2Mx32)
- Reorder D3647-63001

Searching the web for these reference numbers, I found these SIMMS have
the following characteristics:
- 8MB
- EDO
- 60 ns
- 72 pin

Okay, but now what kind of memory do I *need* for my PS/1 model 2123
?

Thank you,
Daniel

AFAIK both IBM and HP fiddled with the Presence Detect pins on these
modules. If it is not an EDO issue, then it could be that the PS/1's
BIOS/chipset does not know how to correctly interpret the PD data, or
the PD pins may not be programmed. If it is a PD issue, then you could
possibly reconfigure the SIMMs by adding or removing links to/from
pins 67-70. For example, an 8MB 70ns IBM SIMM (p/n 92F0102) connects
pin 69 to ground and leaves the others open.

- Franc Zabkar

 

[daniel_lafosse]

Please pardon my curiosity, what is the reason you want to resurrect
this dinosaur that I thought was extinct long ago? Even with memory
upgrade, what it can be used for, except for a computing history
museum exhibit? Even high end P3 systems are getting junked these
days because their time has passed...
NNN

It's indeed just for computer history. I collect various computers and
I had the chance (?) to find this PS/1. Now I intend to put Linux on
it, but it will never run with only 2 MB of RAM. So I'm looking forward
to add two 8 MB SIMMs to it.

Of course, the performance of this machine (386 SX at 20 MHz) is
ridiculous. And indeed, stuff like complete Pentium II or Pentium
III-class machines can be found for like 20 EUR.

Anyway SIMMs that will work on this PS/1 seem hard to find. I've
googled with "PS/1 Model 2123" and some sites sell such RAM, but 1)
it's expensive for old stuff and 2) it's not 100% sure they will work
on this machine...

Cheers,
Daniel

 

[daniel_lafosse]

Sorry but I don't think I'm able to go solder the pins. That's pretty
difficult for me.

I see some people are selling "PS/2" memory on ebay. Does that mean
that kind of memory chip will work on my PS/2 2123 ?

Thank you,
Daniel

 

[chrisv]

It's indeed just for computer history. I collect various computers and
I had the chance (?) to find this PS/1. Now I intend to put Linux on
it, but it will never run with only 2 MB of RAM. So I'm looking forward
to add two 8 MB SIMMs to it.

DOS

 

[The Black Wibble]

[...]

Of course, the performance of this machine (386 SX at 20 MHz) is
ridiculous. And indeed, stuff like complete Pentium II or Pentium
III-class machines can be found for like 20 EUR.

Anyway SIMMs that will work on this PS/1 seem hard to find. I've
googled with "PS/1 Model 2123" and some sites sell such RAM, but 1)
it's expensive for old stuff and 2) it's not 100% sure they will work
on this machine...

1) For a semi-rare PC which ~I~ value for historical reasons, I'd pay a lot
more for 16MB of RAM than what's being asked for your PS/1 Pro 2123. $32 +
P&P is piddlely. I've paid more for a bottle of Bourbon.

2) You look and the manufacturer part number, then check if the item
advertised for the 2123 is sold by other web sites for the 2123. If so, I
don't know how one can me more certain.

Tony.

 

[nobody]

DOS

And possibly Win3.x - though it will run like a snail on 2MB RAM. At
least, this fits more to the historic period than Linux.

 

[The little lost angel]

And possibly Win3.x - though it will run like a snail on 2MB RAM. At
least, this fits more to the historic period than Linux.

Hmm but didn't Torvalds created Linux to run on his 386 because Unix
wouldn't? So likely Linux would still run on this old 386 but at the
same snail crawl?

 

[daniel_lafosse]

Hmm but didn't Torvalds created Linux to run on his 386 because Unix
wouldn't? So likely Linux would still run on this old 386 but at the
same snail crawl?

Yes, Torvalds wrote Linux for the 386, and indeed Linux will run on a
386, even a 386 SX (you need to enable math emulation when you build
the kernel).

But, I'm intending to install Debian GNU/Linux 3.0 "woody", and it will
not run with less than 16 MB of RAM.

Thank you,
Daniel

 

[Robert Redelmeier]

Hmm but didn't Torvalds created Linux to run on his 386
because Unix wouldn't?

Not quite. XENIX did, but he wanted to use all the
nice new 386 hardware features like paging.

So likely Linux would still run on
this old 386 but at the same snail crawl?

For sure! I still use Linux on an old Compaq aero
laptop 486sx25 (8 MB). It is fine, especially with
the HD mounted NOATIME.

RAM is a worse constraint on these older machines.
Linux can be made to boot in 768KB but really isn't
usable with less than 4 MB, and X takes at least 16.

-- Robert

 

[nobody]

Not quite. XENIX did, but he wanted to use all the
nice new 386 hardware features like paging.


For sure! I still use Linux on an old Compaq aero
laptop 486sx25 (8 MB). It is fine, especially with
the HD mounted NOATIME.

RAM is a worse constraint on these older machines.
Linux can be made to boot in 768KB but really isn't
usable with less than 4 MB, and X takes at least 16.

Whereas Win3.1 will start on 640k, and will be useable (it'd be able
to run something like Winword/Excel/Access/Powerpoint 6 and have more
than 1 window open at a time) starting with about 4MB, maybe even 2MB
will do, though it's 16 bit only. Heck, with 6MB+, it'll be able to
boot even Win95 to GUI, and with 10MB (IIRC, this is what it'll get
after adding the 8MB SIMM to existing 2MB) it will be able to install
Office95, HD space permitting. I remember using AutoCAD R12 Windows
on a 386 (though DX 33) with 8MB RAM under Win3.1 - it was barely
useable, but still useable.

NNN

 

[Franc Zabkar]

Sorry but I don't think I'm able to go solder the pins. That's pretty
difficult for me.

I see some people are selling "PS/2" memory on ebay. Does that mean
that kind of memory chip will work on my PS/2 2123 ?

Thank you,
Daniel

Kingston's website (http://www.kingston.com) suggests that a suitable
8MB SIMM for the PS/1 model 2123 is Kingston's KTM0130.

From Kingston's archives:

==================================================================
Also equiv. to IBM p/n: 72G9203, 72G9202, 70G9821, 12H1405 FRU 4081

Mfgr's System P/N's:
6450130 (IBM); 92G7202 (IBM); 92G7203 (IBM); 92G7520 (IBM); FRU
93F8268 (IBM); O70PS (IBM)
==================================================================

Several sellers on the Net describe the KTM0130 module as "8MB 2Mx36 -
70ns 72Pin" which means that it supports parity error checking. Your
HP module (2Mx32) does not.

- Franc Zabkar

 

[Keith]

Whereas Win3.1 will start on 640k, and will be useable (it'd be able
to run something like Winword/Excel/Access/Powerpoint 6 and have more
than 1 window open at a time) starting with about 4MB, maybe even 2MB
will do, though it's 16 bit only. Heck, with 6MB+, it'll be able to
boot even Win95 to GUI, and with 10MB (IIRC, this is what it'll get
after adding the 8MB SIMM to existing 2MB) it will be able to install
Office95, HD space permitting. I remember using AutoCAD R12 Windows
on a 386 (though DX 33) with 8MB RAM under Win3.1 - it was barely
useable, but still useable.

Whereas DOS will boot in 48K...

 

[nobody]

Whereas DOS will boot in 48K...

But since 2MB are already present, they can be utilized by putting
Win3.x on top of DOS. And my choice would be 3.11 - solely for its
networking capabilities out of the box.

 

[Scott Alfter]

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RAM is a worse constraint on these older machines.
Linux can be made to boot in 768KB but really isn't
usable with less than 4 MB, and X takes at least 16.

Way back in the day, I had X running on a 386SX with 4 MB, with a mono-VGA
monitor connected through a 256K VGA card. With a custom modeline and some
tweaking of the knobs on the monitor, I was even able to get it running at
800x600 instead of 640x480 (though I had to settle for a 50-Hz refresh rate
to do that).

You'd probably have to track down old versions of Linux and X to do this,
though. I don't know what would've been current for X at the time, but
Linux hadn't even hit v1.0.

_/_
/ v \ Scott Alfter (remove the obvious to send mail)
(IIGS( http://alfter.us/ Top-posting!
\_^_/ rm -rf /bin/laden >What's the most annoying thing on Usenet?

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