The following list gives the chronological history of PS/2 models as they were introduced. Microchannel (MCA) models are printed bold.

1987 Apr 2

IBM 8530, PS/2 Model 30. 8-bit ISA bus (PC), Intel 8086 processor.

1987 Apr 2 to 1991 July 23

IBM 8550-021, PS/2 Model 50. 16-bit MCA bus at 10 MHz, Intel 80286 CPU.

1987 Apr 2 to 1990 Oct 31

IBM 8560-041 and 8560-071, PS/2 Model 60. 16-bit MCA bus at 10 MHz, Intel 80286 CPU. Model 8560-041 came with the ST-506/412 HD controller, while 8560-071 had an ESDI HD controller.

1987 Apr 2

IBM 8580-041 and 8580-071, PS/2 Model 80 386. 32-bit MCA bus at 16 MHz, Intel 80386 DX CPU. Model 8580-041 came with the ST-506/412 HD controller, while 8580-071 had an ESDI HD controller.

1987 Aug 11

IBM 8525, PS/2 Model 25. 8-bit ISA bus (PC), Intel 8086 CPU. Integrated monitor made this computer look like a Mac.

1988 Jun 2

IBM 8525-L01, 8585-L04, PS/2 Model 25 Lan Station. Like 8525, but with LAN adapter. L01 contains a monochrome, L04 a color monitor.

1988 Jun 2 to 1991 July 23

IBM 8550-031 and 8550-061, PS/2 Model 50 Z. 16-bit MCA bus at 10 MHz, Intel 80286 CPU.

1988 Jun 2

IBM PS/2 Model 70 386. 32-bit MCA bus at 16 MHz (Exx), 20 MHz (0xx, 1xx), or 25 MHz (Axx), Intel 80386 DX CPU.

1988 Jun 2 to 1991 Nov 9

IBM PS/2 Model 70 486. 32-bit MCA bus at 25 MHz, Intel 80486 DX CPU.

1988 Jun 2

IBM 8580, PS/2 Model 80 386. 32-bit MCA bus at 20 MHz (111, 311), Intel 80386 DX CPU.

1988 Sep 13 to May 1992

IBM 8530-E01 and 8530-E21, PS/2 Model 30 286. 16-bit ISA bus (AT), Intel 80286 CPU. 8530-E01 came with 2 floppy disk drives, 8530-E21 with one floppy drive and one harddisk.

1989 May 9

IBM PS/2 Model 55 SX. 16-bit MCA bus at 16 MHz, Intel 80386 SX CPU.

1989 May 9 to 1991 Jul 23 (models 031 and 061)

IBM PS/2 Model P70 386. 16-bit MCA bus at 16 MHz (model 031) or 20 MHz (models 061 and 121), Intel 80386 CPU. Portable, weight 9.5 kg.

1990 Mar 20 to 1991 Jul 23

IBM 8565, PS/2 Model 65 SX. 16-bit MCA at 16 MHz, Intel 80386 SX CPU. Came as model 8565-061 with a 60 MByte HD and model 8565-121 with 120 MByte HD.

1990 May 10

IBM 8525, PS/2 Model 25 286. 16-bit ISA bus (AT), Intel 80286 CPU.

1990 Nov 12

IBM PS/2 model P75 486. 32-bit MCA bus at 33 MHz, Intel 80486 DX CPU. Portable of weight 10kg.

1991 Mar 26

IBM 8040, PS/2 Model L40 SX. 16-bit ISA bus (AT), Intel 80386 SX CPU. Portable of weight 3.5 kg.

1991 June 11

IBM 8535, PS/2 Model 35 SX. 16-bit ISA bus (AT), Intel 80386 SX CPU. Also available as Model 35 LS as a diskless workstation, in model 35 LS-24X for token ring, and 35 LS-14X for ethernet LAN.

1991 June 11

IBM 8040-043 and 8040-045, PS/2 Model 40 SX. 16-bit ISA bus (AT), Intel 80386 SX CPU. 8040-043 had a 40 MByte HD, 8040-45 an 80-MByte HD. These computers were optionally usable as desktop or tower PCs.

1991 June 11

IBM PS/2 Model 57 SX. 16-bit MCA bus at 20 MHz, Intel 80386 SX (04x) or 80386 SLC (05x) CPU.

1992 Feb 25

IBM PS/2 Model 56 SX, SLC, LS, LS SLC. 16-bit MCA bus at 20 MHz, Intel 80386 SX (04x) or 80386 SLC (05x) CPU. Comes with SCSI adapter.

IBM 9533, PS/2 E.

IBM 9553, PS/2 Model 53 486 SLC2. 16-bit MCA bus at 25 MHz, 486 SLC2 CPU. Models 0B7 and 0BB come with 120 and 250 MB HD, respectively.

IBM 9553, PS/2 Model 53 LX 486 SLC2. 16-bit MCA bus at 25 MHz, 486 SLC2 CPU. Diskless. Models 1BX has an Ethernet card, 2BX a Token Ring card.

IBM 9556, PS/2 Model 56 486 SLC3.

IBM 9556, PS/2 Model 56 LS 486 SLC3.

IBM 9557, PS/2 Model 57 486 SLC3.

IBM 9576, PS/2 Model 76.

IBM 9577, PS/2 Model 77.

IBM 9577, PS/2 Ultimedia Model 77.

IBM 9585, PS/2 Server 85.

IBM 9595, PS/2 Server 95.

IBM 9595, PS/2 Server 95 Array.

IBM 8600, PS/2 Server 195.

IBM 8600, PS/2 Server 295.

.. more to come soon ..

References

• Upgrading and Repairing PCs, by Scott Mueller. Addison-Wesley, 3rd edition 1994. ISBN 1-56529-467-X. German translation: Hardware Praxis. 3rd edition 1994.
• IBM Personal Systems: A Business Perspective. By Jim Hoskins. John Wiley and Sons, 7th edition 1994. ISBN 0-471-59930-1.