14 Apr
2000
14 Apr
'00
4:17 p.m.
I can't
help with your question, but you may want to post it on
comp.sys.ibm.ps2.hardware....
Yes, that was going to be my next move....as you say they're VERY helpful
over there!! 
15 Apr
15 Apr
3:45 p.m.
Hi!
Heres a PS2/50z question.
Mine only has 1meg, looks like 72pin simm but none I have seem work.
All of them happen to be 8x32 (16chip).
There is only one SIMM socket. What is the limit for ram (max)?
Where can I get something bigger than 1mb?
All PS/2's insists on parity only of specific sizes and speeds. Find
512K x 36 faster than 80ns and check the detectation pins is set
for 2MB, 85ns otherwise solder time, peter's, and ohlandl's
websites has the info you need to check against.
2MB max on planar, 16MB total using 16bit MCA memory
expansion card or two.
As my internal network progresses this box has value as I have a SMC 10bt
NIC for it. I figure OS/2 warp V3 or Win3.1 would be a good os for it.
Being 286 there are few unix based OSs with a networking that run well on
it.
Look for a 486SLC2 upgrade module by IBM (best) to plug into over
the 286 socket.
Honestly, I rather go for Model 70-Axx or 80-Axx (tower), 90 if one slaps on 3.11
or OS/2 3.x. I have got 70-Axx and 90, perfect boxes for that
OSes applications yours just described.
Allison
Wizard
17 Apr
17 Apr
1:31 p.m.
Hi,
Heres a PS2/50z question.
Mine only has 1meg, looks like 72pin simm but none I have seem
work. All of them happen to be 8x32 (16chip).
I don't really know too much about PS/2s yet, I'm only just starting to
investigate these machines (I've got 3 - a Model 50, a Model 80 and a Model
95).
There is only one SIMM socket. What is the limit for
ram (max)?
Where can I get something bigger than 1mb?
Interesting, my Model 50 has a pair of SIMM sockets on the planar. They look
more like 30-pin SIMMs than 72-pin ones, but I haven't taken them out to
check yet. Also, I've never seen SIMMs like these before - the PCB is a
brown/beige colour, and the RAM chips are in small silver "cans" rather than
the usual black epoxy.
Anyway, I suspect you'll find that the limit for RAM (on the
motherboard/planar/whateveryouwanttocallit) will be 2Mb. IBM used to make
these wierd, double sided, 2Mb 72-pin SIMMs specifically for some models in
the PS/2 family.
I remember these SIMMs distinctly since around 10 years ago they used to
sell for practically nothing on FidoNet as they were of no use whatsoever in
anything but a PS/2.
TTFN - Pete.
--
Hardware & Software Engineer. Sound Engineer.
Collector of Arcade Machines, Games Consoles & Obsolete Computers (esp DEC)
peter.pachla(a)wintermute.org.uk | www.wintermute.org.uk
--
9:49 p.m.
On 17 Apr 2000, at 23:31, Peter Pachla wrote:
Hi,
> Heres a PS2/50z question.
>
> Mine only has 1meg, looks like 72pin simm but none I have seem
>work. All of them happen to be 8x32 (16chip).
Must be 36bits and correct presence detection pins set.
There were two or three speeds but same capacity on 512K x 36
simms.
I don't really know too much about PS/2s yet, I'm only just starting to
investigate these machines (I've got 3 - a Model 50, a Model 80 and a Model
95).
8550-xxx?
8580-xxx?
x595-xxx? Yes there is 8595 and 9595's.
I upkeep my small set of PS/2s and have researched much, one
newgroups for the ps/2 is out there (comp.sys.ibm.ps2)
Interesting, my Model 50 has a pair of SIMM sockets on
the planar. They look
more like 30-pin SIMMs than 72-pin ones, but I haven't taken them out to
check yet. Also, I've never seen SIMMs like these before - the PCB is a
brown/beige colour, and the RAM chips are in small silver "cans" rather than
the usual black epoxy.
Allison's is 50z. Yours is the early 50. Users complained of lazy
performance, IBM responded with 50z, better memory subsystem
performance w/ 10mhz 286 cpu (0WS) and faster and tad bigger hd
capacity.
BTW, those pair of simms are nonstandard 30pin IBM 512K x 9bit
on also nonstandard pinout. 50z uses standard parity 72pin with
correct detect pins set.
Anyway, I suspect you'll find that the limit for
RAM (on the
motherboard/planar/whateveryouwanttocallit) will be 2Mb. IBM used to make
these wierd, double sided, 2Mb 72-pin SIMMs specifically for some models in
the PS/2 family.
Just plucked a 32bit MCA Kignston memory 4 x 72pin slots card
from C.R. for prissy 5 USD. Going into 70-Axx with more
of those
hacked 2MB sticks.
I remember these SIMMs distinctly since around 10 years ago they used to
sell for practically nothing on FidoNet as they were of no use whatsoever in
anything but a PS/2.
Those 2MB 72pin parity simms?
Those are common 512K x 36bit 85ns, Most of them can do 80ns
after moving the one SMD resistor one spot. Duly done that to
several and using them in my 70-Axx.
55sx, 50z, 70's and some PS/2 machines that uses these.
Wizard
8862
days inactive
8866
days old
3 comments
3 participants
participants (3)
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allisonp＠world.std.com -
jpero＠cgocable.net -
peter.pachla＠wintermute.org.uk