SCSI /A  made in Japan

   IBM SCSI /A's sold in Japan. Some are not seen in Louis's page or MCA Picture Book.
   Long unchached ( Trible ) and Long SCSI w/c ( spock, older/newer ) are not listed here. 

   Short  SCSI A/16 
   Short SCSI A/16 ( New Microcode )
   Short  SCSI A/32 with Cache ( Yellow Terminator Pack )
   Short  SCSI A/32 with Cache (  SIP Terminator  Packs )
   Half   SCSI  /A with Cache (  50Pin Flat Ribbon Inner Connector )
   Half SCSI/A  ( 50pin header Connector Type)
   SCSI A/32 with 2.5" HD

   SCSI investigation

Short  SCSI A/16 ,   P/N   07G3169 
    Short length version of  uncached SCSI /A  with AIC6250EL and old SCSI micro code set.
   Long uncached SCSI /A  was equipped in PS/55 5570 ( analogous to 8580 25MHz type) .
   I suppose this short card was an optional part for 5530-U/V but not sure. 
U1   HM6264LFP 
U2   64F4376 ( 27C256 ) 
U3   64F4377 ( 27C256 ) 
U4   84F8233 ( 27C256 ) 
U5-U8 ALS373 
U6   N8032AH 
U7   OKI 15F7917 
U9   33F6715 
U10  OKI 33F6910 
U11  Adaptec AIC 6250EL

Y1   125KD 
Y2   20AKSS1M 
RN1-3 Terminator Register Packs 

Short SCSI A/16  P/N 35G2976 (  there are serveral P/N for this adapter ) 
    See explanation at Louis's page

Short SCSI A/32 with Cache  ( Auto Termination ),  P/N  35G2818 
    This is the Latest SCSI 32/A, probably an option for 5551-Rxx.  Basically this adapter  is capable to 
     handle drive >1G.  Unfortunately  most of PS/55s( except 9595 and 8595-J ) can't handle IML drive 
     larger than 1G with this adapter due to BIOS issue.. 
     8595-Jxx ( 1S1P planar with type-3 50MHz complex ) with this adapter can handle HD over 1G as 
     IML drive.  SCSI ID for IML drive is not restricted to #6 for this combination. 

U1  84F8324 
U2/U7  9336HAK,  TC514256AJL-70
U3/U8  9336HAK,  TC514256AJL-70
U4/U9  9336HAK,  TC514256AJL-70
U5  ODD   92F2245 
U6  EVEN 92F2244
U10  15F6903 
U11  33F6715 
U12  10G4890 
U13  Intel N80C188XL 20 
U14  M5M5256BFP-12L
F1  Fuse *1
Y1  20.000 
Y2  32.000
Y3  25.000 
RN1 Yellow DIP Terminator
     *1 F1 Fuse refused ! 
     I once fried up  F1 Fuse when I attached a Rancho's Single/Differential  converter. Really got shocked
     because that was the only one "beyond 1G capable card" I had back then. I trolled around parts shops
     in Akihabara and got a similar type of tiny chip named  "Poly switch ".  Electrical specification was a bit
     different but with the chip my card revived. 

Short SCSI A/32 with Cache  ( SIP Terminator Register Packs ),  P/N 07G3063 
U1   84F8324 
U2/U7  9306HAK ( T51256T-70 ) 
U3/U8  HM512456AJP8 ( cache  ) 
U4/U9  HM512456AJP8 ( cache  )
U5   ODD 92F2247 
U6   EVEN 92F2246 
U10  15F6903
U11  33F6715 
U12  10G4891 
U13  Intel N80C188-16 
U14  M5M5256BFP-12L

F1    Fuse 
Y1    20.000
Y2    32.000 
Y3    25.000 
RN1-3 Register Packs( removable ) 
RN4    Register ( soldered) 

2/3 Length Cached SCSI A ( 50pin header Connector Type),  P/N 95F4488 
 This adapter is an earlier version of SCSI 32/A and was equipped in 5561-W1x/W2x models. 
 SCSI micro code set is 64F4356/57 and it can't handle drive > 1G as ID6. 
 Probably this is the only one with usual 50pin flat ribbon inner connector among all of IBM's genuine
 SCSI /A  for PS/2 and PS/55.      ... But there is another one . See below for P/N  79F1140.


U1     Adaptec AIC-6250EL 
U2/7  M5M4256AL-10 ( ZIP RAM ) 
U3/8  M5M44256BL   ( Cache, ZIP RAM ) 
U4/9  M5M44256BL   ( Cache, ZIP RAM ) 
U5     HM62256LHP-15T 
U6     ALS373 
U10   BIOS P/N 64F5984 
U15   64F4376  EVEN 
U19   64F4377  ODD 
U18   OKI 15F7917 
U20-24  ALS45A 
U25   ALS244B 
F1   Fuse
Y1   20.000 
RN4-6 Terminator packs 
RN7    R 

J1    DB50 SCSI Header

2/3 Length SCSI A ( 50pin header Connector Type),  P/N 79F1140 

     Not sure about this one.  Maybe uncaching  SCSI for 5560-W0.
     Got this one recently (2003.05.11 ).     This one has 2 internal connectors, one is 50pin flat ribbon 
     cable connector and the other is 50pin edge card connector. 

U1     BIOS P/N 84F8233 
U2    64F4376  EVEN 
U3    64F4377  ODD 
U10  33F6910   M91V034 OKI 
U12  33F6715
U20 HM6264ALFP-15R 
U21 N8032AH 
U24 Adaptec AIC-6250EL 
U25 15F7914 M91H048 OKI 
F1   Fuse
Y1   20.000 H
Y2   Unknown
RN1-3 SIP Terminators
J1    50 pins SCSI  Connector
J2    50 pins Edgecard connector
J3    Extrnal RS6000 style connector


SCSI 32/A with 2.5" HD ,    P/N 35G3785 
    2.5" SCSI HD is mounted on the adapter.  The drive is set to ID #6. 
    The stock HD is WDS280 ( 80MB ). 
    Would like to swap the drive to a bigger one( I mean capacity ). 

U1/2   HM514256AJP8
U3/6/7/8  HM514256AJP8
U4      84F8324
U5      15F6903
U9      10G4890
U10    33F6715
U11    intel N80C188-16 
U12    92F2244  EVEN
U13    92F2245  ODD
Y1  20.000
Y2  25.000
Y3  32.000

       All chips on the PCB are same with short SCSI 32/A with cache P/N35G2818 with Yellow DIP
       Terminator.  Just the parts are reallocated on the PCB. 

SCSI investigation 

I'm not sure if I'm correct or I'm totally wrong in following section. 
I tested and experienced by myself thus I wrote.  I can't explain my experience logically 'cause I can't read BIOS or don't have sufficient documentation about PS/55's SCSI feature.

It is told that PS/55's BIOS lacks, unfortunately,  support for over 1G IML drive.  Even if we use 92F2244/  92F2245 SCSI BIOS and 10G4890 microcode,  PS/55s such as 5580, 5560 and 5551-N can not accept IML drive larger than 1G capacity.  Server models like 9595( type 4 ) , 8595 ( Type-3 ) and 9585 are capable to run drives >1G as IML and they are basically same with pure PS/2.  In another word,  BIOS ROM in Japanese localized processor complexes ( and planar ) are not sufficient to take drives > 1G as it's IML drive even though we use SCSI adapters with enhanced SCSI code.  We have such nice cards over here but it's true.    It's Ridiculous and Sad..

 Group A. Adapters not capable to handle >1G IML drive and/or Boot drive
  P/N   Size   Equipped BIOS P/N   ROM Type   Terminator   Remarks
 6451018  Long,  32bit    5580-Y  64F4376/77  EPROM   None   *2
 15F6561  Long,  16bit   5570-V  64F4376/77  EPROM   DIP   *1
 95F4480  2/3,     32Bit   5560-W1  64F4376/77  Flat package   SIP   *2
 07G3169  Short, 16bit    51-W ?  64F4376/77  Flat package   SIP   *1

 Group B.  Adapters capable to handle  >1G IML drive and/or Boot drive.
  P/N  Size  Equipped  BIOS P/N  ROM Type  Terminator  Remarks
 35G2976  Short, 16bit   92F2244/45  Flat package   DIP  *1, *3
 66G1080  Short, 16bit    92F2244/45  Flat package   DIP  *1, ( *3 ?) 
 35G2818  Short, 32bit  51-R ?  92F2244/45   Flat package    DIP  *2, *4, 
 07G3063  Short, 32bit   Option   92F2246/47  Flat package    SIP  *2, *4
 6451280  Short, 32bit   Server  61G3929/30  Flash ROM  *2,  Corvette
 92G1572  Full,    32bit  8595-Jxx  92F2244/45  EPROM   DIP  *2, *4

  *1 Non-Cache
  *2 With Cache 
  *3 Not capable to handle partition larger than 1G as a boot drive
  *4 Capable to handle partition larger than 1G as a boot drive

  Flat package  ; Don't know correct term for the ROM.  It's a flat, SOJ type ROM ( write-one-time ) 

  5580-Y with Type-A UpGrade complexes( DX2-66) , HD;  Seagate ST42400N ;
     Can't make system partition on the Seagate even with an adapter listed under Group B. 
     The seagate drive IDed as 6  off from 35G2818 can't be recognized as valid drive for IML.
     If I use a smaller drive with ID=6 and make system partition on it, then change boot order to  Seagate
     2G in one partition as C,  then system works.  Here, if I change SCSI /A to listed under Group A, 
     system stops upon booting with error message " Missing Operating System ".  If I change older type
     of  SCSI /A  to newer one again such as 35G2818 or 07G3063,  every thing works fine. 
    If I change Type-A Upgrade to Type-3,  the seagate drive off from  35G2818 and  6451280  ( both in
    Group B ) works fine as like as usual PS/2 with Type-3 platform. Also I can give SCSI ID other than 6
    to ST42400N.


Conclusion ( If I'm correct )
  1. Pure PS/55s dose not contain SCSI code in it's BIOS or lacks some important codes relating SCSI.   
    Server models ( 5580 and 5560 ) may handle drives larger than 1G if BIOS ROM could be replaced.
    IBM Japan had not ever released such BIOS ROMs nor reference versions. I'm not a BIOS
  2. SCSI adapters listed in group A can not handle drive larger than 1G for IML porpose.
    Also it can't boot OS even IML drive is smaller than 1G and  boot order is changed to another drive 
    larger than 1G in which OS is installed.
  3. SCSI Adapters listed in group B can handle drive larger than 1G for IML porpose only when it is used 
    with PS/2 complexes including PS/55 type-3
    .  In this case SCSI ID for IML drive is not limmited to ID 6.
    With Japanese type-1/2 and dx2-66 upgrades, SCSI adapters in groupe B on 5580/5560 can't do it.
  4. As a matter of fact, 5551-N  can not handle drives larger than 1G as an IML drive  even though it has 92F2246/2247 micro code set on the planar. 

    Why Big Blue Japan deleted SCSI code from machine BIOS ?


PS/55 Index