Ed. This page was originally HERE.
Okay, biggie PS/2 questions answered. There are actually several different
flavors of Model 70.
- 8570-E61 long board(planar): 16Mhz Bus. FRU 93F7309.
- 8570-E61, -081, -061 short planar: 16Mhz Bus. FRU 41G3984.
- 8570-061, -081, -121, -161 long planar: 20Mhz Bus. FRU 96F7308.
- 8570-061, -081, -121, -161 short planar: 20Mhz Bus. FRU 41G3985.
(This is the machine type that I have & on which this is based.)
- 8570-AXX: 25 Mhz Bus. FRU 92F0580. 80386 processor board FRU 15F7659.
- 8570-BXX: 25 Mhz Bus. FRU 41G3979. 80486 processor board FRU 92F0103.
There still exists a overview of 8570 systems at IBM Canada, if you
haven't visted them yet.
The reference diskette you will want to use for these machines will
be the RF7080.EXE self-extracting file unless you happen to have
a 70-486, in that case check out the 8570 Type 3 & 4 Planar page.
These machines should all be easy to cope with provided you give them
72-pin, gold-tinned parity SIMMs at least 85 ns fast for all but AXX and
BXX; those two will need faster refresh 80 ns SIMMs. The FRUs to use would
be 92F0104 (85 ns) and 92F103 (80 ns)... or you can do 'British Museum' approach
and simply try a SIMM out and see how the machine responds - either with
an error, or the 'Automatically Reconfigure (y/n)?' dialog. The virtue of
the trial-and-error method is that no brain cells whatsoever get hurt, but
it might involve repeatedly opening & closing the machine's case - and
increasing the risk of an inadvertent static discharge to your system.
The AXX & BXX critters are constructed differently, they will allow
you to put as much as 8MB on the planar in two 4MB SIMMs, all others have
a maximum motherboard limit of 6MB divided into 3 2MB SIMMs. The maximum
amount of memory any 8570 system will talk to is 16MB unless you do some
creative finagling (See IBM Memory
Expansion & BOPT103.EXE). This is due to the DMA
(direct MEMORY access, get it?) controller only having 24 address lines -
which gives you 16MB worth of individual addresses. Now while we can all
stand around and criticize IBM for this shortsightedness, it might be helpful
to remember the prices for SIMMs in about 1989 and what software demanded
of a system then. You can still have a very nice system (multitasking, GUI-enhanced,
TCP/IP-able) in 16MB or less if you pick the right software for it.
20Mhz -061 system w/ short planar
As I originally received my system, it had 4MB of RAM and an IBM 60MB
hard disk, all slots open, and the 386 processor already replaced with the
Cyrix Cx486DRx2 (the large green chip in the JPG image to the left). I've
since improved it by filling out planar RAM to 6MB, adding the IBM 80386
Matched Memory Adapter card, 8514/A, and Kraft Serial/Game card (I don't know
about games, but it's well worth the second physical serial port). I've
also changed hard disks, first to an 80MB IBM ESDI, then finally to a 120MB
ProCom PMC120 1/2 height drive that is compatible with IBM Direct Bus Attach/ESDI.
And a second floppy drive. I've got an NEC SCSI host card I'd like to use...
when I've got the bucks to blow on some external SCSI devices.
The machine has been run at least once beyond IBM's recommended operating
temperature range. The fact that it has forgiven me speaks very well of
the system's reliability. IBM's recommended range: 60 deg F - 90 deg F
(15.5 deg C. - 32.2 deg C.) I got a mysterious TRAP E (page fault error)
Wall thermometer said 110 deg F (42.3 deg C.) Add 20 deg to figure out
what the core chip temps were... about 130 (54.5 deg C.) Ouch. We haven't
done this again.
What's gone wrong: Well, nothing really that you wouldn't expect from
a 10-year old computer that probably hasn't always gotten the best of care.
I've so far only replaced the power supply (no beepy-beepy), and the Drive
riser card (when the system failed to acknowledge that disk C: existed).
Am on monitor number 3, keyboard number 2, battery number 2. These minor
maintenance issues aside- the machine has provided faultless performance.
Anybody know what the MTBF for a 8570 is?