Parallel Port Chipsets

Parallel Port Chipsets

As of 20251105, I'm bug hunting. Trust, but verify...

IBM PS/2 Micro Channel Parallel Port Chipsets and NVRAMs

8550   1 FBFF, 72X8299 A, 72X7377 D, MC146818 8550z 1 FBFF, 05F3994 A, 90X8134 D, MC146818 8555 T1 1 FBFF, What A? , 90X8134 D, DS1287 8555 T2 1F5FF, WhatA? , 90X8134 D, DS1287, 2K CMOS Ext 8556     1E6FE, 91F7490 A, 92F1495 S, DS1285Q/1210S 8560   1 F7FF, 72X8299 A, 72X7377 D, MC146818, 2Kx8 8565-SX 1 E3FF, What A? , 90X8134 D, DS1287, DS1220 [2Kx8] 8570 T1 1 DFFF, 72X8299 A, 90X8134 D, MC146818, 2Kx8 8570 T2 1 F3FF, 33F5838 A, 90X8134 D, MC146818, 8Kx8 8570 T3 1 F9FF, 72X8299 A, 63F7520 D, MC146818, 8Kx8 8573 70O 1 FFAF, 72X8299 A, 90X8134 D, MC146818, 8Kx8 8573 70N 1 F4FF, 33F5838 A, 90X8134 D, MC146818, 8Kx8 8573-P75 3 E0FF, What A? , 90X8134 D, MC146818, 8Kx88580 T1 1 FF6F, 72X8299A, 72X7377 D, MC146818, 2Kx8 8580 T2 1 FF6F, 72X8299A, 72X7377 D, MC146818, 2Kx8 8580 T3 2 FF6F, 72X8299A, 90X8134 D, MC146818, 8Kx8 8590 T1 3 FF6F, 64F0942 A, 90X8134 D, DS1285/1210, 8Kx8 8590 T2 3 FF6F, 64F0942 A, 92F1428 D, DS1285/1210, 8Kx8 8590 T3 3 FF6F, 64F0942 A, 10G7808 D, DS1285/1210, 8Kx8 8590 T4 3 FF6F, 64F0942 A, 50G8192 SSC, DS1285/1210, 8Kx8 9553     3E3FE, 10G4672 A, 96F7690 S, DS1387 [4Kx8]9556     3E1FE, 10G4672 A, 96F7690 S, DS1285/1210, 32Kx8[?] 9576 B   3 DFFE, 10G4672 A, 63F7520 D, DS1285/1210, 8Kx8 9576 L   3 EE79, 10G4672 A, 71G0438 S, DS1585 [8Kx8] 9585 X   3 FFDC, 10G4672 A, 10G7808 D, DS1485 [8Kx8] 9585 K   3 FEDF, 10G4672 A, 10G7808 D, DS1585 [8Kx8] 9595 A 4 E4FE, 10G4672 A, 92F2384 E, 50G8192 SSC, DS1285 [8Kx8]
A - ASIC, D - DMA, S - System, SSC - SynchroStream Controller, E - ExpressPrint
MC146818A has 64 Bytes of CMOS
DS1287 has 64 Bytes of battery backed CMOS
DS1387 has 64 Bytes of battery backed CMOS -AND- 4Kx8 NVRAM
DS1x85/1210 uses external NVRAM
NVRAM sizes in brackets means internal NVRAM

NOTE: Model 90 systems use either the 64F0942 -or- 33F5469 ASIC
NOTE: "H" complexes use the 92F1428 -or- 10G7808 DMA controller
NOTE: 95A use 92F2384 -or- 61G2800 ExpressPrint cntrlr -AND- 50G8192 SSC

Combinations of I/O and DMA/System Controllers

DMA is NOT Supported
72X8299 I/O and 63F7520 DMA
72X8299 I/O and 72X7377 DMA
33F5838 I/O and 90X8134 DMA

DMA Supported
72X8299 I/O and 90X8134 DMA
91F7490 I/O and 92F1495 System
64F0942 or 33F5469 I/O and 90X8314 or 10G7808 DMA -or- 50G8192 SSC
10G4672 I/O and 63F7520 or 10G7808 DMA -OR- 71G0438 System
92F2384 or 61G2800 and 50G8192 SSC [ExpressPrint]

At this time, it appears that an 8Kx8 NVRAM is needed for a DMA Parallel port. It is unclear if combinations where DMA is NOT supported would actually work IF there was 8Kx8 of NVRAM.

Type 1 DMA Parallel Port

"Parallel Port"
   The parallel port can be set as Parallel 1 through 3 or disabled.
     "PARALLEL 1"   io 03bch-03bfh
     "PARALLEL 2"   io 0378h-037fh
     "PARALLEL 3"   io 0278h-027fh
     "Disabled"

Type 2 DMA Parallel port
The 72X8299 I/O looks to be limited to the three Type 1 PARALLEL I/O ranges. PARALLEL_1 cannot switch from 03bch-03bfh to 1278h-127fh when you enter enhanced mode. The Type 2 ONLY supports Arbitration Level 6.

It is only found on the Model 8580-Axx FFF9 with 72X8299 I/O -AND- 90X8314 DMA w/ 8Kx8 NVRAM

"Parallel Port"
   Parallel port can be assigned as Parallel 1 through Parallel 3 or disabled.
     "PARALLEL_2 (DMA)" io 0378h-037fh int 7 arb 6
     "PARALLEL_3 (DMA)" io 0278h-027fh int 7 arb 6
     "PARALLEL_1"    io 03bch-03bfh int 7
     "PARALLEL_2"   io 0378h-037fh int 7
     "PARALLEL_3"   io 0278h-027fh int 7
     "Disabled"

Type 3 DMA Printer Port
   The Type 3 DMA Parallel port supports "PARALLEL_1" with a second I/O range of 1278h-127fh. This second I/O range is used when using an Arbitration Level.
The Type 3 supports Dedicated or Shared Arb levels for all PARALLEL.

Parallel ports with 64F0942 or 33F5469 I/O -AND- 90X8314 or 10G7808 DMA -OR- 50G8192 SSC supports Dedicated or Shared Arb levels on three PARALLEL

"Parallel Port"
   The parallel port can be set as Parallel 1 through 3 or disabled.
     "PARALLEL 1"   io 03bch-03bfh 1278h-127fh int 7
     "PARALLEL 2"   io 0378h-037fh int 7
     "PARALLEL 3"   io 0278h-027fh int 7
     "Disabled"

"Parallel Port Arbitration Level"
   The parallel port can be set to any available arbitration level. If shared, other devices can be set at the same level. If dedicated, only this device can be set to that level. Select <Disabled> to use the port in compatibility mode.
    <"Shared 7">, 6, 5, 4, 3, 1, 0
     "Dedicated 7", 6, 5, 4, 3, 1, 0
     "Disabled"

8573-P75 "Type 3-ish" DMA Parallel port

The P75 E0FF has an unknown I/O and 90X8134 DMA. It supports Dedicated or Shared Arb levels on four PARALLEL.

NOTE: P75 "Type 3-ish" DMA Parallel adds "PARALLEL_4" io 1378h-137fh int 7 . The I/O ranges resemble those of the 10G4672 I/O, -BUT- the Arbitration levels can only be dedicated, NEVER Shared. Perhaps the unknown I/O controller is the precursor to the 10G4672 ?

"Parallel Port"
   The parallel port can be assigned as Parallel 1 through Parallel 4 or disabled.
      "PARALLEL_1" io 03bch-03bfh 1278h-127fh int 7
      "PARALLEL_2" io 0378h-037fh int 7
      "PARALLEL_3" io 0278h-027fh int 7
      "PARALLEL_4" io 1378h-137fh int 7
      "Disabled"

"Parallel Port Arbitration Level"
   The parallel port can use arb levels 0 through 7 or Disabled [compatibility mode]
      "Level 6", 5, 4, 3, 1, 0, Disabled, 7

10G4672 I/O Based Type 3 DMA Parallel Port

The 10G4672 I/O with the 63F7520 or 10G7808 DMA -OR- 96F7690 or 71G0438 "System Controller" supports Dedicated or Shared Arb levels with four PARALLEL. Note that the 91F7490 I/O and 92F1495 System controller [8556] seems to duplicate the 10G4672 I/O.

NOTE: The 10G4672 or 91F7490 I/O add "PARALLEL 4" io 1378h-137bh int 7. Why IBM added PARALLEL_4 is unknown to me.

"Parallel Port"
   The parallel port can be set as Parallel 1 through 4 or disabled.
      "PARALLEL 1" io 03bch-03bfh 1278h-127bh int 7
      "PARALLEL 2" io 0378h-037bh int 7
      "PARALLEL 3" io 0278h-027bh int 7
      "PARALLEL 4" io 1378h-137bh int 7
      "Disabled"

"Parallel Port Arbitration Level"
   You can use any available arbitration level. Shared - other devices can use same level. Dedicated, only this device can use that level. <Disabled> to use port in compatibility mode.
    <"Shared 7">, 6, 5, 4, 3, 1, 0
     "Dedicated 7", 6, 5, 4, 3, 1, 0
     "Disabled"

Type 4 High Speed or Express Print Parallel Port

92F2384 or 61G2800 and 50G8192 SynchroStream [ONLY in a Model 95A] supports Dedicated or Shared Arb levels with four PARALLEL -AND- SCB Mode.
Note the addition of SCB Mode, this puppy is a true Busmaster. At this time, it is unclear how much of IEEE 1284 the ExpressPrint incorporates since it predates the IEEE 1284 spec.

"High Speed Parallel Port A"
   The high speed parallel port A can be set as Parallel 1 through 4 or disabled.
      "Parallel 1" io 03bch-03bfh 1278h-127fh int 7
      "Parallel 2" io 0378h-037fh int 7
      "Parallel 3" io 0278h-027fh int 7
      "Parallel 4" io 1378h-137fh int 7
      "Disabled"

"Parallel Port A DMA Arbitration Level"
   The high speed parallel can use any DMA arb level. Shared - other devices can use same level. Dedicated - only this device can use that level. <Disabled> to use compatibility mode.
      "Shared level 7", 6, 5, 4, 3, 1, 0
       Dedicated "Level 7", 6, 5, 4, 3, 1, 0
      "Disabled"

"Parallel Port A SCB I/O Address"
   The high speed parallel port can be set to any available SCB I/O address. Under normal circumstances this address range does not need to be changed.
      "8100-8102", 8900-8902, 9100-9102, 9500-9502, A100-A102, A900-A902, B100-B102, B900-B902, C100-C102, C900-C902, D100-D102, D900-D902, E100-E102, E900-E902, F100-F102, Disabled