191-079 PS/2 Model 70 386 (081, 161, A81 AND A16)
189-144 New Models of IBM PS/2 Model 70 386 (8570-061 and 8570-A61)
188-079 PS/2 Model 70 386 (8570 E61/121)
188-078 PS/2 Model 70 386 (8570-A21)

SHS64F3993 IBM PS/2 Model 70 HMR
SHS15F2197 IBM PS/2 Model 70 HMS

Type 1 Planar (386 16 MHz)
Type 2 Planar (386 20 MHz)
Type 3 & 4 Planar (386 or 486 25 MHz daughterboard)
Reply OEM Planar (486 33 MHz)

8550 and 8570 - Common Devices

Sigma Data Quick Easy Disk Adapter (replacement riser w/ IDE)

Mouse Locking Up 8570 During Boot
Overclocking
Integrated Fixed Disk and Controller ADF

Memory

Min/Max on system board:
1/6 MB (Exx,1xx), 2/8 MB (Axx/Bxx) (expandable to 16 MB)
85 ns SIMMs on 16 MHz and 20 MHz planars, 80 ns SIMMs on 25 MHz planars
ROM: 128 KB
Cache: 0 KB (Exx), 0 KB (1xx), 64 KB SRAM L2 cache (386 25 MHz planar only)

8570 Models

E61 - 386-16, 1MB, 60MB, 1.44
121 - 386-20, 2MB, 120MB, 1.44
061 - 386-20, 2MB, 60MB, 1.44
A61 - 386-25 w. 64kb cache, 2MB, 60MB, 1.44 **
A21 - 386-25 w. 64kb cache, 2MB, 120MB, 1.44 **

** These models can be upgraded with the 486DX-25 "Power Platform" and BIOS upgrade chips, making them a true 8570-486. The planar is shown on the 8570 Type 3 & 4 Planar page.

Mouse Locking Up 8570 During Boot

Konradin Stenner wrote:
   I have four 8570 ( -161 and -121s) with a boot problem. These 8570s have a dual async adapter and an NI GPIB card installed and are used to control spectrometers [which cost 500,000 DM new] and they cannot change the software (Xenix).
   During boot happens nothing when the mouse, no matter which one I use, is connected. The monitor does not go from standby to operate mode, there is no harddisk or disk access to see. When the mouse is disconnected system does boot. When I connect the mouse during the boot, it works fine.

Dr. Jim Shorney says:
   Clean the system board and power supply with compressed air. An excessive buildup of dust can cause strange problems.
   Also, this may sound totally off-the-wall, but try a different keyboard. The KB and mouse use the same controller. Or, the mouse port connector could be worn out or damaged, have broken solder connections, etc., which could be causing a latchup of the data lines when a mouse is plugged in.

Konradin reports success:
   Thanks all, and special thanks to Jim, who had the right idea! The DEC keyboard was changed to a Dell keyboard and now the machine does boot.

Overclocking

Alban Kellerbauer wrote:
   Some of you may remember that I repeatedly inquired about other people's experiences with overclocking PS/1 and PS/2 machines, where by overclocking I mean replacing the clock oscillator with a faster one. Since nobody seems to have done this before, I had no choice but to try it myself.

   I have a model 8570-061 that came with a 386DX-20 running, obviously, at 20 MHz (clock oscillator at 40 MHz). I de-soldered the oscillator and inserted a full-size oscillator socket (there are solder holes for either a half-size or a full-size oscillator). The socket permitted me to try different oscillators without soldering and de-soldering more than once.

   I found the socket in the Digi-Key catalog (part number A462-ND). I then replaced the CPU with a 386DX-33 and inserted first a 66 MHz oscillator (Digi-Key part number CTX137-ND), which didn't work, and then a 50 MHz oscillator (part number CTX121-ND), which worked. Just in case that wouldn't work either, I had also bought a 40 MHz oscillator (part number CTX120-ND), because the de-soldered oscillator's legs are not long enough to firmly sit in the socket. I had the 8570 running DOS and Windows 3.0 running for several hours without any problems.

AdapterID DF9F Integrated Fixed Disk and Controller

DMA Arbitration Level
   DMA channel used to transfer data
      <"Level 5">, 6, 7, 0, 1, 3, 4

DMA Burst Pacing Interval
   Time interval between DMA transfer bursts during which the Micro Channel is released by the fixed disk controller for use by the processor.
      <24 Microseconds>, 31, 16, Burst Disabled"

DMA Pacing Control
   Enables or disables the DMA Burst Pacing Interval.
      <"Disabled">, Enabled

Time to Release
   This controls the amount of time that the fixed disk controller will keep the Micro Channel after being preempted. If the 'DMA Pacing Control' is set to <Enabled>, the Time to Release will default to immediate. Under normal circumstances, select <6 Microseconds>.
   <"6 Microseconds">, 3, Immediate

Fairness On/Off
   Bus Arbitration Fairness. This controls whether the adapter will release control of the bus when it has been using it exclusively
   <"On">, Off

Primary/Alternate Port Addresses
   Port addresses used by the adapter. Either <Primary> or <Alternate> will work equally well. If there are two integrated fixed disks, then select <Primary> for one and <Alternate> for the other.
   <"Primary" (io 3510h-3517h)>, Alternate (3518-351f)