IBM Memory Expansion
1-8MB 286 Memory Expansion (30 pin)
2-8MB Memory Expansion, 16-bit  (72 pin)
   Factory Upgraded 2-8MB Memory Expansion 85F0408 / 10G3812
80386 2-8MB Memory Expansion Adapter, 32-bit (72 pin)
2-14MB  Enh 80386 Mem Expansion (FDDE, FDDF)
   Identifying FDDF Old, New, and FDDE 
BOPT103.EXE - Upgrade SC.EXE and Mem Expansion ADF/ROM
   Functions of BOPT

512KB/2MB 286 Memory Expansion Adapter 72X8532 / 90X8167

* ADF for FEFE is built into refdisk and not a separate file.

1-8MB 286 Memory Expansion Adapter 1497253 / 61X6752
U1-4,21-24 30 pin SIMMs
U8 LIA3307 61X6715
U14 Firmware 11FB069 '88 or 61X6724 '87 

  This adapter provides 1MB of memory expansion with LIM EMS Version 4.0 support for all PS/2 Models 50, 50Z, 55 SX, 60 and 65 SX.

Expanded Memory Adapter 0-8 MB XMA
@F7FE.ADF "IBM Expanded Memory Adapter 0-8 MB XMA"

188-084 IBM Personal System/2 0-8MB Expanded Memory Adapter/A
       The PS/2 1-8MB 286 Memory Expansion Option is functionally equivalent to IBM's existing 2-8MB 80286 Memory Expansion Option (#8286, 6450609), but with 1MB of standard 85ns memory.  It is expandable in increments of 1MB or 2MB up to a maximum of 8MB by using 1MB SIMMs-85ns or 2MB SIMMs -85n.

" Optional 0-8MB Expanded Memory Adapter/A Cards (1497259, #7259) can be added to enhance system memory.  Each card may be expanded from 0 to 8MB.  Multiple cards can provide a maximum of 16MB of memory on the system, with one wait state.  Refer to Product Announcement 188-084, dated June 2, 1988, for additional information."

2-8MB Memory Expansion Adapter, 16-bit P/N 15F8292
@F7F7.ADF - IBM 2-8MB 286/386SX Memory Expansion Option
@194.PEP -

CN1-4 72 pin SIMMs
U6 SLA7620F
Scan from Cheers, down in Australia

U6 SLA7620F CMOS High Speed Gate Array Datasheet

David Beem said:
     The IBM "2-8[MB]" 16-bit memory card (P/N 15F8292) has four 72-pin SIMM sockets & an EPROM (on the middle of the upper edge). If you have the newer EPROM version (copyright 1991 AFAIR) you can populate all four sockets with 2Mb 80nS SIMMs for an additional 8MB to the possible 55SX planar 8Mb (16Mb, maximum on the 24-bit addressed 386SX).

   For systems with 24 bit addressing and 8MB on planar (like the 55SX), the older EPROM version prompts about resizing memory with a non-fatal error requiring a keypress to continue every boot. Once the error is acknowledged the system is fine from there. In this case, it is better to populate the last SIMM socket with a 1Mb 80nS module (allowing 15MB total system memory) in that case (or find someone to burn an EPROM of the newer version). The card's RAM is treated as being "Extended", same as the upper planar memory. I treat the newer EPROM as mainly having (other differences haven't been studied) the "OK, OK, just cut the memory to size & don't tell me about it" code.

     Cheers reports the older EPROM version as "Copyright 1989 V2". The newer is a double date of "1990, 1991" AFAIR & may have "V3". Never have seen the original ("V1", if such thing were marked) in the wild out of a half-dozen cards. The later version is on less than half the cards in that same (very) rough sampling.

     This card is excellent filling both the 55SX & 65SX (the only MCA 286/386SX systems able to use it & have 8MB of planar memory maximum) to capacity with Extended RAM. The 609 or other 16-bit MCA memory cards with software could perhaps eclipse it by supporting more than 8MB on the card (for something like the 50/50Z/60 models) or being able to split itself for Extended & Expanded memory.

19498 Errors With 2-8MB 80286 Memory Adapter H12398

Failing systems with the following:
-  2 - 8MB 80286 memory expansion adapter installed, FRU P/N 15F8292 printed on back.
-  Total of 16MB installed in the system.
-  System fails with a 19498-16xxx POST error.

Some 2 - 8MB memory expansion adapters may fail with a POST error of 19498-16xxx (xxx can be any number).  This is a false error in systems with 16MB total installed memory, and can be corrected by replacing the memory adapter EPROM. PS/2 systems that support the 2-8MB 80286 memory expansion option should not be configured with more than 16MB total memory. If more than 16MB is installed, a 19498 POST error is valid and will not be corrected by EPROM replacement.

If the system displays the 19498-16xxx error code, replace adapter EPROM with FRU P/N 57F2905. In systems with two 2-8MB adapters installed, replace the EPROM on both cards.

The 2 - 8MB adapter has only one EPROM socket, located along the top edge of the card at location U1. A correctly installed EPROM will have its small notch facing left, away from the bus connector.

Until the EPROM is replaced, a 19498 error may be bypassed with the F1 key, leaving the system fully functional.

Factory Upgraded 2-8MB Memory Expansion, Front 85F0408 / 10G3812

Factory Upgraded 2-8MB Memory Expansion, Rear 85F0408 / 10G3812

Oh, it finally makes sense....

The 2-8MB Memory Expansion P/N 15F8292 was probably upgraded at factory (the stickers are perfectly aligned) with the 57F2905 EPROM -AND- had a sticker to cover the original FRU - P/N on the back. I expect if you carefully peeled up the right hand sticker, you would see 15F8292

I've not seen any references to adapter rework or defective components. It appears the only difference between the 15F8292 and the later 85F0408 is the 57F2905 EPROM.

No, I don't have the BIN file for the 57F2905 EPROM. Sorry...

 2-8MB Memory Expansion Adapter 32-bit  90X9556 or 90X9369

@FCFF.ADF - IBM 0-8MB 386 Memory Expansion Adapter 
CFCFF.ADF - Init file for @FCFF.ADF 


CN1-4 72 pin SIMMs 
U8,9 150nS delay
U19 SLA7340F1A 
Card was donated by David Ress from Ohio. 
2 meg 85ns SIMMs - FRU # 92F0104 (option number 6450604) 

U19 SLA7340F1A CMOS High Speed Gate Array Datasheet

2-14MB Memory Expansion Adapter FDDF and FDDE
FDFF 34F2825 Enhanced 80386 Memory Expansion Adapter (old 2-14)
   - FRU P/N 87F9916 IBM PS/2 Enh. 80386 Memory Exp. Adapter (old, resistors added)
   - IBM PS/2 Enhanced 80386 Memory Expansion Adapter (new) white socket
FDDE 88F0075 Enhanced 80386 Memory Expansion Option (FDDF plus 8K EEPROM)

Ed Avis confides to the world:
IIRC there were three variants of the 2-14 card:

- without ROM: this writes IADF code to the MBR of the boot device. Generally a bit of a pain and won't work with Linux (though I have heard that it works if you use the Minix bootloader to boot Linux).  I already have one of those cards.

- with ROM: this counts its memory at the same time as the planar memory (like the 2-8 card does) and is easier to install.  Apparently if you have one 'with ROM' card it can also take command of any 'without ROM' cards and let them work without needing boot track code.

Apparently there are two variants of the 'with[out] ROM', I don't know if there is any difference in use.

Supports 1MB, 2MB, and 4MB 80nS or 85nS IBM memory. 
Mandatory Replacement ENHANCED Enhanced 80386 Memory Expansion ECA 042

Identifying the FDDE, FDDF (old) and FDDF (new) Adapters
  All three share the same basic outline.

The FDDF (old), FDDF (new) and FDDE all use the L1A4452 / 49F5505 chip.

P/N 49F5507-on adapters manufactured before July 1, 1990
P/N 87F9819-on adapters manufactured on or after July 1, 1990

Option - P/N 87F9916 possible error codes are 231, 241 and 251. There are no components between the SIMM sockets.
Installation Instructions Form Number G571-0183
Hardware Maintenance Supplement Form #G571-0184
Technical Reference Form Number G571-0185

Adapter - P/N 88F0075 possible error codes are 18431, 18441 and 18451.
Components are mounted between the SIMM sockets.
Installation Instructions Form Number G571-0226
Hardware Maintenance Supplement Form #G571-0225
Technical Reference Form Number G571-0227

IBM Enhanced 80386 Memory Expansion Adapter

Enhanced 80386 Memory Exp. Adapter 
@FDDF.ADF - IBM Enh. 80386 Memory Exp. Adapter 
CFDDF.ADF - Init file for @FDDF.ADF - required ! 
IFDDF.ADF - Init file for @FDDF.ADF - required ! 
@FDDF.ADF - IBM Enh. 80386 Memory Exp. Adpt alt file / more settings

FDDF (old) Enhanced 80386 0-14MB Memory Adapter/A  49F5507 or 87F9819

U8 bel A447-0150-28 / 72X8359 Delay Module, 150nS total delay
U7 bel A447-0075-62 / 72X8360 Delay Module,75nS Total Delay
U15 L1A4452 / 49F5505

   The IBM Enh. 80386 Memory Exp. Adapter (FDDF old) totally lacks the resistor networks between the SIMM sockets. It only has two epoxy coated capacitors on the left edge (not three).

ECA042 recalls the 49F5507 and replaces it with the 88F0075 -IF- 4MB SIMMs are to be used on it. 1MB and 2MB SIMMs are unaffected. Uplevel options 34F3011 and 34F3077 which use FRU P/N87F9916, replace option 34F2811 which used FRU P/N34F2825. This is done as a precautionary measure due to the possibility of undetected data modification with 4MB SIMM(S) installed on this adapter.

FDDF (old, patched) Enhanced 80386 0-14MB Memory Adapter/A

Jelte sent this in.  P/N 34F3011 FRU 87F9916 - PCB is 34F3053
J1 and J2 were filled with 2MB 80ns SIMMs, P/N 65X5806, FRU 92F0103.

From my stash, no jumper wires, but diagonal wirewound resistors. Jelte's card has the equivalent resistor connected across pins of U21-U24, plus more rework. I must czech my card's PCB FRU against his, mine might have a downlevel PCB, lacking the changes to inner PCB traces. Or, maybe not. It is an IBM thing...

Systems which have the Enhanced 80386 Memory Expansion adapter installed (FRU P/N 34F2825) may also experience OS/2 TRAP Errors if the Enhanced 80386 Memory Adapter does not have resistors located diagonally across the modules located in positions U21, U22, U23, AND U24.  RETAIN RECORD #H037481 should be referenced for additional details.

H035585 Capacitors May Obstruct SIMM Placement On Adapter 


A few Enhanced 80386 Memory Option Adapters may have capacitors obstructing SIMM placement. SIMMs which are not fully seated can create intermittent memory failures.

If a capacitor prevents proper SIMM placement in connectors J2, J3 or J4:

J2: Gently bend C3 45 degrees to the right of J2
J3: Gently bend C4 45 degrees to the right of J3
J4: Gently bend C5 45 degrees away from J4

NOTE: This applies ONLY to the 80386 Memory Expansion Adapters with capacitors under the RIGHT end of a SIMM connector. All later versions have relocated the capacitors from under the RIGHT end of SIMM connectors to the RIGHT of the SIMM connectors.

FDDF (new) Enhanced 80386 0-14MB Memory Adapter/A 88F0075

Same layout as the FDDE with 3x teardrop capacitors on left, resistor networks between SIMM sockets, and the two Delay Networks moved from a vertical orientation (right of the single SIMM socket) to a horizontal orientation to the left of U50. The only way you can distinguish the new FDDF from the FDDE is a single WHITE SIMM socket on the upper right of the FDDF. Looking at Jelte's downlevel FDDF with all white SIMM sockets, maybe this is why the last FDDF revision had one white socket, since the original FDDF had black sockets, one uplevel card had all white sockets, so a way to differentiate the newest version was to have three black and one white SIMM socket. YMMV...

NOTE: The FDDF card supports enabling or disabling Matched Memory.

"Matched Memory Cycles"
          "This memory card can disable Matched Memory Cycles for use on machines which do not have Matched Memory Cycles compatible with the original 16MHz Model-80."

NOTE: Further meditations on "The Micro Channel Architecture Handbook" leaves me with the impression that the MMC is not limited to only the 8580-16MHz, the 8570-Bxx, and the 8573-P75. It says the system figures out what it can support.

FDDE Enhanced 80386 0-14MB Memory Option 88F0075 / 95F1155

@FDDE.ADF - IBM Enh. 80386 Memory Exp. Adapter w/ROM
CFDDE.ADF - Init file for @FDDE.ADF

2-14mem.exe Files for 2-14MB 80386 Memory Expansion Adapter

   The IBM Enhanced 80386 Memory Option (FDDE) has the resistor networks between the SIMM sockets, three epoxy coated capacitors to the left of the three SIMM sockets, two horizontally aligned delay transformers to the left of 49F5505, an 8K EEPROM (U4) and the upper right SIMM socket is BLACK..

J1-J4 72 pin SIMM socket
U4 8K x 8 bit EEPROM
U50 L1A4452 / 49F5505

U4 HN58C65FP-25T EEPROM, 8192-Word x 8-bit CMOS ROM datasheet 
D1 bel A447-0150-28 / 72X8359 Delay Module
D2 bel A447-0075-62 / 72X8360 Delay Module

  Which makes me wonder which came first.  My Pocket Reference sez 

Option#  FRU #    Feature Code      Description
87F9856  87F0075  9856     4MB Mem Adpt (32 bit, 80nS)
87F9860  87F0075  2190     4-14MB Mem Adpt(32 bit, 80nS)

   Look below for the latest Enhanced memory adapter update- BOPT103.EXE, it will update SC.EXE and the BIOS ROM on your adapter. 

BOPT103.EXE (>16MB in a 70/80)

bopt103.exe BOPT103 Upgrade

Note - Your Reference Diskette MUST be:
50/60  version 1.06 or greater
55/65  version 1.04 or greater
70/80  version 1.10 or greater
70-486 version 1.04 or greater

   Reference Diskette update is most easily accomplished on a system with two 3.5 floppy drives. If a single drive is used, diskette swapping is required (may be as high as 55 swaps). In order for the new Enhanced Memory Adapter to boot up there must be at least 1Meg of "free" memory below the 16Meg limit. If the sum of system planar memory and any non-Enhanced Memory Adapter system memory is 16Meg or more, you must move some of that memory to the Enhanced Memory Adapter (or remove it from your system) in order to use the new Enhanced Memory adapter.

What does bopt103.exe do?
Peter Wendt woolgathers
  BOPT103 is a workaround to overcome the 16MB RAM limit on Mod. 70/80 with the crippled DMA with using 1 x FDDE and 1 x FDDF card. It works - but it blocks two 32-bit slots .... leaving only one single 16-bit slot on a Mod. 70 ...

    In simple words the BOPT workaround asks you to install a maximum of 15MB on the systemboard and the FDDE card leaving a 1MB "addressing gap" for the memory on the FDDF card. This results in a total of 31MB in the best case. Don't know if a second FDDF card is also supported, but I don't think so.

     The better choice is to forget about the FDDE and FDDF cards and use e.g. a Kingston KTM-64000 or Acculogic SIMMply RAM 32-bit card that have own memory mapper and error-detection logic. I have the Acculogic in one of my Mod. 80-A31 and have a total of 40MB installed. The KTM should be able to push the memory up to 64MB (8MB on the planar - 3 x 16MB + 1 x 8MB on the card) - but I haven't got the chance to test that. The Acculogic supports only 8MB modules. 

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