9556-9557 refdisk v1.10 - supports SLC3
9556-9557 diags disk v1.10 - supports SLC3
9556 486SLC2 and 486SLC3
9557 486SLC2 Systems
9557 486SLC3 and Multimedia Systems
Parallel Port Trivia (DMA Arbitration)
486SLC2 Planar 39G6410
J4,5 DB9 Serial ports
J6 HDD15 Video
J7 C60 SCSI
J9,11,12 72 pin SIMMs
J13 Bus Riser
J16 50 pin SCSI
J18 Power-supply connector P1
J19 Control-panel connector
J20 Power-supply connector P2
J21 44 Pin floppy header
J22 Unpopulated. Leads to 8032B
JMP1 Override-jumper connector
JMP2 Privileged-access password
JMP3 LogicLock header
L11 Toroid for video?
OS1 40.0000 MHz osc MCA Bus
OS2 22.1184 MHz osc
OS3 14.3181 MHz osc
OS4 50.0000 MHz osc CPU clk
OS5 24.0000 MHz osc FDC clk
|R14 KB/Mouse PTC Fuse
R60 SCSI PTC Fuse
R224,228 PTCs for what???
ST1,2 Termpacks for SCSI
U13 Dallas DS1285Q
U16 Sony CXK58257AM-10L
U34 Dallas DS1210S
U35 121 pin 387 socket
U36 50G6950 486SLC2
U52 Sony CXK58257AM-10L
U59 Siemens 8032B-20-N
Y1 32.768 KHz xtal
Y2 4.0 MHz xtal
50/25-MHz 486SLC2, 16KB L1, three SIMM sockets 70ns parity checked
2, 4 and 8MB SIMMs supported.
How should I fill the memory? One 8 and two 4MB or 2 8MB SIMMs?
8MB, so you can use interleaved memory access. Use MEM1 and MEM2
(Ed. Aron Eisenpress reported
this really applies to the 8556/57 models, he tried the 9556/57, and saw
no improvement. )
>does anyone know of a card to increase the memory on a 9556, I know
its a 386 based machine with a 486 upgrade, Will the 386 memory boards
(from kingston or ibm) work in these machines
Peter snarls back:
Yes. Highly recommended is the Kingston KTM-609 II - since it supports
XMS memory - what the IBM 1-2 and the 0-8 XMA don't.
Integrated 32-bit XGA-2
1024x768, 256 colours, 75Hz NI
800x600, 65,536 colours
640x480, 65,536 colours
SCSI drive limits: Max size for boot drive is 3.94GB.
NEC CDR-222 and IBM model 9556
Andrew Acton wrote:
Installing CD-ROM Drive Support under DOS running on a
MicroChannel Machine with NEC SCSI CD-ROM Drives.
I recently installed CD-ROM support with the following configuration:
Machine : IBM PS/2 Model 9556 (MicroChannel/SCSI)
CD-ROM : NEC MultiSpin 6X (External Drive)
O/S : IBM PC-DOS 7.0
1) Obtain a copy of the following file from NEC tech support.
I obtained the following file from my local NEC BBS service in Sydney Australia:
PS2.ZIP 101,052 22/09/93 | DOS
Drivers for PS/2 SCSI machines
2) Unzip the file, run the install program (creates a directory on the
dos boot drive called scsi), reboot and you now have CD-ROM access!
3) The installation program updates (in my case):
CONFIG.SYS -> Device=c:\scsi\neccdr.sys /d:NECCD
AUTOEXEC.BAT -> C:\scsi\mscdex /d:NECCD /m:10
The PS2.ZIP package is great because it supplies the the device
driver (neccdr.sys), the Microsoft CD rom extensions (mscdex) and
installs the lot without and problems.
Supports 2.88MB floppy.
Port DMA Arbitration Trivia
The PS/2 machines use a slightly different implementation
of the parallel port that is neither ECP nor EPP but "Arbitrated DMA".
This is a (antique) method to boost up parallel data-throughput up to 1MB/s
- with the disadvantage of an incontigous data-stream (Ed.
the IEEE 1284 standard is only 1.2MB/s!). The data is always transported
with DMA transfers. Therefore many EPP / ECP port drivers cannot handle
that and choke - the IOMEGA is one of these, most parallel-port CD-drives
as well and some HP bidirectional printer drivers cannot handle this too.
Workaround: enter machines configuration and set the Parallel port DMA
"Disabled". This causes the parallel port to work in "compatible bidirectional"
mode - and the ZIP works fine. A little slower maybe, but works. I run
a ZIP on all of my PS/2 with the PP-DMA disabled.
Ian Brown chimes in
Good tip that one Peter. It is also relevant to Ditto
drives, certain versions of Lap Link, and just about anything that is connected
to the parallel port for bi-directional data transfer.
Funny thing, i use a parallel zip on my ps2 77 with no
problem at all. Matter of fact it is far and away faster than any other
machine, including ones that clam to be EPP.
Peter cuts in with:
Depends on. IBM changed the specification a little -or
the BIOS-support on that respectively- on the 95xx-machines as it seems.
The 9556 / 9557 still suffer some problems with the DMA enabled, the later
9576 / 9577 (all planars) seem to be a lot better. The *85*90 / 95 are
known for having problems with various parallel devices (even printers)
when leaving the PP-DMA enabled. My 8595-AKD refuses to handle the Iomega
ZIP-drive properly until I switched the parallel port DMA to "disabled".
Basically it is a good idea to disable the DMA if one
might experience problems with parallel CD-drives or scanners on all PS/2
(which use DMA printer port) to test whether the device is working at all
or if there is a cabling problem at all.
CHRISTIAN A. ROBERTS
*SHRUG* My Iomega Ditto2Gb didn't get along with my 9556 slc3-75's
parallel port, so I found a Boca Research MCA Parallel adapter...it worked
for awhile, then went belly-up, too.
Peter finishes up with:
Point a) try the Ditto directly on the parallel-port with the DMA disabled
Point b) there is a lot trouble reported with BOCA cards (Hi Allen
which I can sort only under "strange incidents". I had some Boca cards
installed in various servers and *none* of them caused any trouble
- unlike to similar AMS-cards, which scrambled the arrangement of LPT-ports
(LPT1 becomes 2, LPT3 becomes 1 and LPT2 becomes inactive ... or such).
This "sudden death" of Boca PP-cards is more than myterious. I probably
could understand if that happened on very fast PS/2 (like "Lacuna"-77i,
Server 95A, 8595 with Type 3 DX-50 or all Type 4 platforms) ... but not
with a Mod. 80 or a 9556 ... !
I noticed that a 9556 with its' case removed, plugged in, power
switch off (no fan or drives whirring), felt very warm to touch on
top of the power supply.
Peter has a flashback and sez:
You had just experienced the "standby power warming effect"
The power supplies on various PS/2 (33, 35/40, all 56/57, all 76/77,
85, all 90/95) do not really "switch off" - a part of the PSU is always
active and the frontside power button in fact switches only a "sense voltage"
from the standby part of the PSU against GND ... which starts up the main
Especially the PS/2 Mod. 9556 PSUs are known for a high
failure rate. Once having opened the PSU you will find parts of the printboard
having gotten dark-brown from the heat emmitted by components. Particularly
know for "sudden death by aging" are the Italian Magnetek
PSUs for the 56. They cannot be repaired ! I have tried that various times.
They use a sort of "hybrid circuit" for the PSU-internal failure detection,
which seemed to be fried after some components died by thermal overstress.
I have replaced various diodes, resistors and the main switching hi-voltage
VMOS transistor (all were defective) - and the PSU did not work but fried
some larger resistor I'd replaced some minutes before.
Recommendation: try to get some spare PSUs. The IBM models
35, 56 and 76 small desktops use the same PSU (and Mod. 40, 57 and 77 large
desktops use the same larger PSU as well) And: use a common line breaker
to fully separate the machine from the AC-power when not in use for a longer
period of time.
The machine itself is a nice little thing with reasonable
performance. The case might be a little tight and does not offer much room
for expansions, but you could replace the harddisk against a more modern
and much faster 2.16GB DCAS-32160 from IBM (or anything up to 3.94GB),
install a CD-ROM drive and expand the memory up to 16MB ... XGA-2 video
comes standard and gives acceptable results even with Win95.
BTW: the machine might not run with the cover removed. There's a little
blue security switch at the frontside, which shuts down the PSU when released
(= when the cover is removed). You need to push the security switch inside/up
to start the machine with the cover removed. Just for completeness.
Background speaker noise
>My Model 57 ps/2 SLC3 75mz emits a loud groan when I shut it down!
It never use to do this. Is an impending power supply failure?
Peter has another flashback:
It is no PSU failure. It is simply a serial failure that occured
assembly of the speaker/frontpanel cable. The "cold" speaker wire is
+5V (of the HD-LED AFAIK) instead of being tied to GND. There was (once)
an "adapter cable kit" available that was plugged between the board and
the cable plug and fixes this misbehaviour. There was an ECA on IBM about
that .. must have it somewhere ... Ah ... here it is:
Some 8556/57 and 9556/57 systems may exhibit low volume
background speaker noise that alters during screen refresh or mouse movement.
Problem Isolation Aids:
Problem is specific to 85xx and 95xx 56/57 models. Symptoms
will probably be most noticable when switching from one application session
Two cable jumpers have been released to modify the speaker cable wiring.
The jumper should be plugged between the speaker cable socket on the planar
and the speaker cable connector.
Details are as follows:
FRU P/N 8130978 (8 pin jumper for i386 8556/8557 systems)
FRU P/N 8130979 (12 pin jumper for i486 9556/9557 systems)
To fix it by yourself: You could unsolder the speaker wires and
measure the voltages on the wires against GND (power supply case) with
the machine running. Use the one which has *not* +5V for the speaker and
another wire directly attached to GND.
I fixed my 9556 with that trick. If I find the time I try checking
wiring on my machine and make a diagram of the proper wiring then ...
but that will take time.
SurePath - 486SLC3 System
This product also features IBM SurePath* BIOS that serves as the interface
and ensures compatibility between hardware and the operating system and
applications. (Ed. Is this another
56 Model Summary Matrix
Model CPU Memory Disk Floppy
DBA SLC2 8-16MB 208 2.88MB
OS/2 or DOS/Win
DB6 SLC2 8-16MB 104 2.88MB
OS/2 or DOS/Win
DE9 SLC3 8-16MB 170 2.88MB
DEB SLC3 8-16MB 245 2.88MB
DED SLC3 8-16MB 340 2.88MB
KBA SLC2 8-16MB 208 2.88MB
KB6 SLC2 8-16MB 104 2.88MB
QBA SLC2 8-16MB 208 2.88MB
QB6 SLC2 8-16MB 104 2.88MB
0BA SLC2 8-16MB 208 2.88MB
0B6 SLC2 8-16MB 104 2.88MB
1EX SLC3 4-16MB None
2EX SLC3 4-16MB None
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