These are the IBM planars, NOT the Reply Corporation planars.

rf7080a.exe   PS/2 8570/8580 reference diskette v1.12
Additional Standard Power Connector
Replacement CMOS Battery
Making a diskette drive adaptor

  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

8570 Power Connector
| -Lead Pin     | +Lead Pin      | V dc Minimum  | V dc Maximum  | 
|     2         |     1          | -  9.0        | -15.0         | 
|     2         |     3          | +15.0         | +15.0         | 
|     2         |    15          | + 6.2         | + 6.2         | 

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ard 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. 

8570 / 8550 Bus Riser Power Hack FRU 90X1111
 Original HERE

JN1 Floppy 1 (A:)
JN2 Floppy 2 (B:)
   The three resistor/capacitor pairs on the riser are for DC-buffering and decoupling. The earlier risers lacked them and once you'd stuffed in 2 FDDs or 1 FDD and a tape problems occured with loss of data during copying and suchlike.

   Please note that clone PC power cables use yellow/black/red, while IBM systems use yellow/black, or red/black/blue. What is important is the position of the conductor. Note that the drive power connector is keyed with bevelled edges.

From Peter Wendt 
Warnings and recommendations:
    The maximum power from this hack is about 5v/1A and 12v/1A so if you have both disk-drives or one disk-drive and a tape-streamer installed ... it is  probably not a good idea anyway. It will -non the less- work in most cases, until the unit driven over this port doesn't take too much power. Most modern Harddisks will not exceed these limits.
    In case of doubt: consult drive manual for its power-consumption. Or don't do the modification. 

    If you have only one disk-drive installed, take the connector of the second drive for modification. Caution!!  Take care not to damage the tiny connections on the board near the connector for Drive 2 while soldering the wires. 

  Remember, that the Mod. 50 / Mod. 70 power-supplies aren't that powerful at all. Especially the Mod. 50 power-supply (94W!!!) is known to have lesser power than assumed.
   If you'd already installed a -386/-486 upgrade, 64Megs of RAM, SCSI-adapter and a Hi-Resolution graphic board it will surely collapse. 

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