10 pin Artifact on Newest SCSI w/cache
Results from upgrading to 2MB cache
   NEW SCSI w/cache (Triple osc) 
Terminator Resistance Values
   Termpack FRU
ADF Sections

It has a burst transfer rate of 16.6MBps, adheres to the industry standard ANSI SCSI interface and is supported in either a 16- or 32-bit Micro Channel slot. 
    The IBM PS/2 Micro Channel SCSI Adapter with Cache is a 32-bit busmaster SCSI adapter containing a 512KB cache buffer that allows system memory to be totally dedicated to running the application rather than a portion being reserved for software caching. This SCSI adapter is recommended where improved data transfer rates and multiple SCSI devices are required and system memory is constrained.  However, 512KB cache is too small for the LAN Server application.  

   The "latest" cached SCSI, FRU 85F0063 (FCC-ID is ANOSPRIME), has no Adaptec chip present and a larger yellow 20-pin DIL terminator chip close to the external port. This card has the strange 10-contact card edge connector close to the internal 50-pin card-edge. It has a third oscillator as well: a 32.0000MHz (Y3). 

Microcode Differences
From Charles Lasitter 
   With the triple oscillator (newest) versions of the Enhanced SCSI w/cache, I see some Microcode differences but don't see much in the way of any particular pattern for when one Microcode will be in use versus another. 
   One adapter has 10G4890 dated 1991. Another has 61G2976 dated 1993.  What is the difference between these two microcodes? I invariably see the "1993" microcode with some unusual looking cache SIMMs, but changing them doesn't seem to make a difference. I see "1993" on some boards labeled as "CARD 1" and others" CARD 3".  There is nothing I can track there. 
   I can't figure out why they would change it if they didn't make something better, but I don't know what that would be or how it would manifest itself. I know that the microcode from triple oscillator adapters can't be switched to the old unterminated adapters, but I'm uncertain about from one two another for the same "3-oscillator" family. 

From Tony Ingenoso 
   (guessing)  There may have been a change to deal with the low-power mode problems of certain microcode level Kazuza series drives...  Had to tweak the heads off the cylinder they were idled over to keep from losing data when the next write (after power restoration) happened to be on that 
cylinder...  nasty problem...OS/2 had an ABIOS patch to deal with it on the pseudo-ESDI versions of the drive. 

Terminator Resistance Values
Fact sheet is HERE

Bourns 4120R-003, -221/331 
Model (41 = Molded DIP), 20 Pins, R = Thick Film Low Profile, 003 = Dual Terminator. Resistance Code in the format R1 / R2,  First 2 digits are significant, Third digit represents the number of zeros to follow. 220 ohm, 330 ohm. 

It looks like this.. 

Termpack FRU
From Tim Clarke
   AFAIK, there is only one FRU for the "internal" termination resistor pack for  the IBM SCSI w/cache (adapter FRU 85F0063) that has the appropriate 20-pin socket and  the IBM SCSI w/o cache (adapter FRU 85F0002).  The termination resistor pack (20-pin) is FRU 57F2870 and, provided you insert it with Pin 1 correctly oriented, should work O.K. 

From Ian Brown
   Interesting bit of history this. And no, you won't find it documented anywhere. IBM was one of the members of the organisation that originally set the standards for SCSI, and as usual they had their own ideas. 
   One of these 'unique' ideas was the ability to be able to set the SCSI ID# remotely from the host adapter rather than having to set it on the device itself. 
   The result of this was the 'legacy' small connector on some 'high end' SCSI hosts, and that awkward RS6000 socket as the external port, which became the IBM standard for a while. 
   The idea was good, but be grateful it never took off, as I understand it required decoding hardware on the devices, which could have left us looking for special 'IBM SCSI' HDD's etc. 
   It was never fully implemented as far as I know, SCAM overtook it. 

  How did I find out? I went to a 'Big Blue' re-union recently, and met one of the original designers of the IBM SCSI host adapters. I'd been wondering about that extra connector for years, so I took the opportunity to ask him. 

I/O Address
    I/O address for adapter. Each adapter must have a unique address range
       <"3540-3547">, 3548-354F, 3550-3557, 3558-355F, 3560-3567, 3568-356F, 3570-3577, 3578-357F

DMA Arbitration Level
   DMA channel used to transfer data.
      < "Level C">, D, E, 8, 9, B, 1, 3, 5, 6, 7

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

ROM Wait State Disable
   Whether a wait state is added to accesses of the ROM on the adapter.
          <"Enable Wait State>, No Wait State

SCSI Adapter Address (ID)
   SCSI ID of the adapter
      <"7">, 6, 5, 4, 3, 2, 1, 0"

ADPItem 1 ROM Address Range
   This field shows the address of the 32K block of memory that is assigned to the adapter.  Only one SCSI Adapter will have the ROM assigned, and any other SCSI Adapter installed will share that  address range. If the ESDI adapter is also installed, then the address of the SCSI adapter must be greater than the ESDI adapter address.