8570 Common Devices

These are the IBM planars, NOT the Reply Corporation planars.
191-079   PS/2 MODEL 70 386 (081, 161, A81 AND A16)
188-079  PS/2 MODEL 70 386 (8570 E61/121)

Tim's IBM 8570 web pages

rf7080a.exe   PS/2 8570/8580 reference diskette v1.12
Replacement CMOS Battery
Making a diskette drive adaptor
Open a Locked Case w/o a Key
Open 8570 (and 8550) Case
Remove/Install Planar
Pinout for Battery/Speaker Headers
Clear a Power On Password
Integrated Fixed Disk and Controller ADF

  Min/Max on system board: 1/6MB (Exx,1xx), 2/8MB (Axx) (expandable to 16MB)
  Type of memory: RAM: DRAM (PS/2 72-pin SIMM) 85ns parity checked (3 sockets (4 on Axx models for 80ns SIMMS)) 
     ROM: 128kb 
     Cache: 0kb (Exx), 0kb (1xx), 64kb SRAM L2 cache (Axx 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 8570-486  page

Opening a Locked 8570 Case (w/o a key!)
From Peter 
   Unscrew the two rear thumbscrews, push the upper case forward as far as possible .... then use a large flat blade screwdriver between upper case and rear wall and lift up the case for about 4 - 5 mm and push it over the lock .... Once having it open you can pull out the lock fixing bracket and remove the cover lock from the rear wall. You see: a potential intruder might only try hard enough to get in ... *thieves* steal the entire machine and break it open at home :-)

Open an 8570 (and 8550) Case


Loosen cover screws. They are captive, so when they turn free, they are done.


Slide the case forward about two inches then lift up.

Remove/Install the Planar
  Pull the floppy, hard drive, and drive riser. Pull up on all of the white platic snaps (get the one under the battery, too!). Pull the drive structure straight up. If it doesn't come up, check the white snaps again.
   You need to remove the power supply as well- the screw locations are carried over from the 8550 and one is directly under the front cornder of the PSU fan.
   Remove the three screws at the back of the system (right above the ports). Remove the screws holding the planar down (only three!). Now for all you 95 veterans, read carefully! Lift the planar straight up! They do NOT have a frame that the spring clip EMC bezel clips onto
   You may need to put your fingers in the port opening in back and pull up- the spring bezel fits inside of a recess. 
   When installing the planar, push the spring bezel down until it snaps into place within it's recess. You will know when it isn't fully seated- the screws from the back will be too low to thread into the mounting points.

Pinout for Battery/Speaker connector

  6 pin Header          Edgecard Socket 
  1 Gnd    4 NC          1 NC     4 Gnd
  2 Gnd    5 Clear       2 NC     5 Gnd
  3 +6v    6 NC          3 Clear  6 +6v

Clear a Power-On Password

Model 50, 60, 70, 80 Override Jumper 
   1.Power-off the computer and unplug the power cord. 
   2.Remove the system-unit cover. 
   3.If the speaker assembly has pins, short pins 2 and 3 together. 
   4.If the speaker assembly does not have pins, insert a meter lead into connector 1 and short the other end of the lead to frame ground. 

With the assembly shorted, power-on the computer. This erases the power-on password. Remove the short after POST is finished. 

AdapterID DF9F Integrated Fixed Disk and Controller

fixedresources int 0e

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.
      vcheck  <"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
   This assigns the 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 (io 3518h-351fh)

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