Multiprotocol Adapter/A

@DEFF.ADF IBM Multi-Protocol Communications Adapter
@DEFF.ADF IBM Multi-Protocol Communications Adapter (no device def., different text)
@DEFF.ADF IBM Multi-Protocol Communications Adapter (separate port and arb. level choices)
   Rename alternative ADFs to @DEFF.ADF

188-024 IBM Personal System/2 Multi-Protocol Adapter/A
186-124 IBM RT PC Multi-Protocol Communications Adapter (RT PC ISA adapter, extra detail)

Multiprotocol Adapter/A Technical Reference (1st Ed., Apr 1987) (68X2220, 80X0837)

Adapter Capabilities
Multiprotocol Adapter - Old (without ZM1)
Multiprotocol Adapter - New (with ZM1)
Adapter Revision Levels
New Level Multiprotocol Adapter (H042637)
01291300 Errors Caused by Multiprotocol Adapter/A (H104733)
DB25 Connector Pinout
Error Codes

Adapter Capabilities

  • Supports ISO/CCITT Level 2 and Level 1 protocols:
    • Level 2: Asynchronous, Bisynchronous (BSC)
      Synchronous Data Link Control (SDLC) /
      High-level Data Link Control (HDLC)
      (Note: SDLC/HLDC mode supports DMA arbitration)
    • Level 1: EIA RS-232C
  • Automatic protocol switching via software at setup
  • Supports half-duplex or full-duplex serial transmissions
  • Supports modems or direct attach
  • Fully programmable at speeds up to 19,200 bps
  • Internal wrap-back test loop for diagnostics

Multiprotocol Adapter - Old (without ZM1)
FRU P/N 72X8530, P/N 72X6821, FCC ID ANO9SA6450348 [P] [P]

J1 DB25 male connector
ZM1 pads for SOIC-8
ZM30 Intel P8255A PPI
ZM36 Intel P8251A USART
ZM42 Intel P8273-4 HDLC/SDLC
ZM57 Intel P8254-2 PIT
ZM58 NS16550V or CV UART
ZY1 1.8432 MHz osc (baud rate gen.)

ZM36 Intel P8251A USART for BSC
ZM30 Intel P8255A or NEC D8255AC-5 PPI expanded modem interface, sync comm. diag aid
ZM58 NS16550V or CV Asynchronous Communications Element for ASYNC
ZM57 Intel P8254-2 timeouts / interrupts for synchronous communications

The rest of the board is covered with 74xx logic, PALs/GALs, and some passives.

Multiprotocol Adapter - New (with ZM1)
FRU P/N 90X8995 (or 85F0004?), FCC ID ANO9SA6450348 [P] [P]

Same as above except for ZM1.

ZM1 74ALS00 (SOIC-14)

Adapter Revision Levels

  • FRU P/N 72X8530 (opt. #6450348, raw card P/N 72X6821), w/o ZM1 - downlevel
  • FRU P/N 90X8995 (opt. #6451003), w/ ZM1, can be reworked to 85F0004 - downlevel
  • FRU P/N 85F0004 - current? (what's the difference vs 90X8995?)

New Level Multiprotocol Adapter (H042637)

Multiprotocol Adapter FRU P/N 90X8995 (option #6451003) replaces FRU P/N 72X8530 (option #6450348). FRU P/N 90X8995 is supported in the following machine type/models.

Note: There is a new level FRU (P/N 85F0004) now available that has in turn replaced P/N 90X8995.

8550-A00, 8550-B00, 8550-C00, 8550-021, 8550-031, 8550-061,
8550-900, 8560-041, 8560-071, 8580-041, 8580-071, 8580-111,
8580-311, 8570-E61, 8570-121, 8570-A21, 8573-061, 8573-121,
8555-031, 8555-061, 8565-061, 8565-121, 8590-xxx, 8595-xxx

Old level Multiprotocol Adapter FRU P/N 72X8530 (option #6450348) is still supported in the 8550-021, 8560-041, 8560-071, 8580-041 and 8580-071.

Old level cards may display error code 10062 or intermittent error codes 10029, 10030, and 10031 if installed in any of the remaining machine type/models listed above this caution.

The new level card is downward compatible (can be used on all models) and will be substituted if an old level card is ordered.

How to identify the two adapter cards:

  1. Raw card assembly P/N 6278226 or P/N 72X6821 are used on the down level adapter. Raw card assembly P/N 90X8459 is used on the new adapter. (Raw card part number is located near the card retainer).
  2. No component is installed at location ZM1 on the down level adapter (ZM1 is located on the upper right hand corner of the adapter). There is a component installed at location ZM1 on the new adapter.

01291300 Errors Caused by Multiprotocol Adapter/A (H104733)


01291300 errors and OS/2 Trap 0002 errors while running applications which use the MPCA (Multiprotocol Adapter/A).

Problem Isolation Aids

  1. The system unit has a 66 MHz or faster processor.
  2. A Multiprotocol Adapter/A is installed.
  3. No diagnostics fail.


On higher speed PS/2 systems (66 MHz and greater), a DMA timeout error may occur due to timing factors associated with speed of the system processor.

The fix for this problem is to replace the MPCA Adapter/A with FRU P/N 96F9156 which corrects the problem. If the MPCA adapter currently installed is FRU P/N 96F9156, this tip does not apply and routine problem determination should continue. Refer to RETAIN record #H017325 for additional information and guidance.

When current inventories of FRU P/N 85F0004 are exhausted, all All orders for it will be automatically substituted to the new FRU, P/N 96F9156.

Non Pentium processor Systems running at speeds at, or below, 33 MHz have no operational problems with FRU P/N 85F0004 and this adapter should not be swapped to the new FRU part number unless:

  1. The MPCA adapter installed is failing -and-
  2. Current inventories of 85F0004 are exhausted.

For information on having FRU P/N 85F0004 reworked to the current level (FRU P/N 96F9156) contact Charlie Hoffecker (Ed. phone number removed).

DB25 Connector Pinout

Lead ID
Signal Name
7N/AAB/102Signal Ground
2OBA/103Transmitted Data
3IBB/104Received Data
8ICF/109Data Carrier Detect
23*OCH/111Rate Select
15*IDB/114Transmit Signal Element Timing
17*IDD/115Receive Signal Element Timing
22ICE/125Ring indicator

* Not used in asynchronous communications mode.
** Not standardized by EIA (Electronics industry Association).

Error Codes

100xxMultiprotocol Adapter/A
10002Multiprotocol Adapter/A any serial device
10006Multiprotocol Adapter/A any serial device
10007Communications cable Multiprotocol Adapter/A
10008Multiprotocol Adapter/A any serial device
10009Multiprotocol Adapter/A any serial device

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Louis F. Ohland, Peter H. Wendt, David L. Beem, William R. Walsh, Tatsuo Sunagawa, Tomáš Slavotínek, Jim Shorney, Tim N. Clarke, Kevin Bowling, and many others.

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