Editing IBM PS/2 (section)

==Models==
{{Main|List of IBM PS/2 models}}
At launch, the PS/2 family comprised the [[IBM PS/2 Model 30|Model 30]], [[IBM PS/2 Model 50|50]], [[IBM PS/2 Model 60|60]] and [[IBM PS/2 Model 80|80]];{{r|byte198706}} the [[IBM PS/2 Model 25|Model 25]] was launched a few months later.
[[File:IBM Personal System2 Intel 286 computer.ogg|thumb|IBM Personal System/2 [[IBM PS/2 Model 30 286|Model 30 286]]. [[Power-on self-test]], [[bootstrapping (computing)|bootstrapping]], power-off]]
The PS/2 Models 25 and 30 (IBM 8525 and 8530, respectively) were the lowest-end models in the lineup and meant to replace the IBM PC and XT. Model 25s came with either an 8086 CPU running at 8&nbsp;MHz, 512&nbsp;KB of RAM, and 720&nbsp;KB floppy disks, or 80286 CPU. The 8086s had ISA expansion slots and a built-in MCGA monitor, which could be either color or monochrome, while the 80286 models came with VGA monitor and ISA expansion slots. A cut-down Model M keyboard with no numeric keypad was standard, with the normal keyboard being an extra-cost option. There was a very rare later model called the PS/2 Model 25-SX which sported either a 16&nbsp;MHz or 20&nbsp;MHz 386 CPU, up to 12&nbsp;MB of memory, IDE hard drive, VGA Monitor and 16&nbsp;bit ISA slots making it the highest available model 25 available denoted by model number 8525-L41.

[[File:25-sx.jpg|thumb|Case badge on a [[IBM PS/2 Model 25|Model 25 SX]] (8525-L41)]] The Model 30 had either an 8086 or 286 CPU and sported the full 101-key keyboard and standalone monitor along with three 8-bit ISA expansion slots. 8086 models had 720&nbsp;KB floppies while 286 models had 1440&nbsp;KB ones. Both the Model 25 and 30 could have an optional 20&nbsp;MB [[ST-506]] hard disk (which in the Model 25 took the place of the second floppy drive if so equipped and used a proprietary 3.5" form factor). 286-based Model 30s are otherwise a full AT-class machine and support up to 4&nbsp;MB of RAM.

[[File:Personal System 2 Model 25.png|thumb|upright|IBM Personal System/2 [[IBM PS/2 Model 25|Model 25]]]]
Later ISA PS/2 models comprised the [[IBM PS/2 Model 30|Model 30 286]] (a Model 30 with an [[Intel 286]] CPU), ''Model 35'' (IBM 8535) and ''Model 40'' (IBM 8540) with [[Intel 80386|Intel 386SX]] or IBM [[386SLC]] processors.

The higher-numbered models (above 50) were equipped with the Micro Channel bus and mostly [[Enhanced Small Disk Interface|ESDI]] or [[SCSI]] [[hard drive]]s (models 60-041 and 80-041 had [[Modified Frequency Modulation|MFM]] hard drives). PS/2 ''Models 50'' (IBM 8550) and ''60'' (IBM 8560) used the [[Intel 80286|Intel 286]] processor, the PS/2 ''[[IBM PS/2 Model 70|Models 70 386]]'' (IBM 8570) and ''80'' used the [[Intel 80386|386DX]], while the mid-range PS/2 ''[[IBM PS/2 Model 55 SX|Model 55 SX]]'' (IBM 8555–081) and used the 16/32-bit 386SX processor. The ''Model 50'' was revised to the ''[[IBM PS/2 Model 50 Z|Model 50 Z]]'' still with 10&nbsp;MHz 80286 processor, but with memory run at zero wait state, and a switch to ESDI hard drives. Later [[IBM PS/2 Model 70 486|Model 70 486]] and 80 variants (B-xx) also used 25&nbsp;MHz [[Intel 80486|Intel 486]] processors, in a complex called the Power Platform.

[[File:DeuxPS2.jpg|thumb|upright|The externally very similar [[IBM PS/2 Model 60|Models 60]] and [[IBM PS/2 Model 80|80]] next to each other]]
[[File:IBM Model70 80386.JPG|thumb|IBM Model 70 (case open over case closed)]]
The PS/2 ''Models 90'' (IBM 8590/9590) and ''95'' (IBM 8595/9595/9595A) used Processor Complex [[daughterboard]]s holding the [[Central processing unit|CPU]], memory controller, MCA interface, and other system components.  The available Processor Complex options ranged from the 20&nbsp;MHz [[Intel 80486|Intel 486]] to the 90&nbsp;MHz [[Intel P5|Pentium]] and were fully interchangeable. The IBM ''PC Server 500'', which has a motherboard identical to the 9595A, also uses Processor Complexes.

Other later Micro Channel PS/2 models included the Model ''65SX'' with a 16&nbsp;MHz 386SX; various ''Model 53'' (IBM 9553), ''56'' (IBM 8556) and ''57'' (IBM 8557) variants with 386SX, 386SLC or 486SLC2 processors; the ''Models 76'' and ''77'' (IBM 9576/9577) with 486SX or 486DX2 processors respectively; and the 486-based ''Model 85'' (IBM 9585).

The IBM ''[[PS/2E]]'' (IBM 9533) was the first [[Energy Star]] compliant personal computer. It had a 50&nbsp;MHz [[IBM 486SLC]] processor, an [[Industry Standard Architecture|ISA]] bus, four [[PC card]] slots, and an [[Advanced Technology Attachment|IDE]] hard drive interface.  The environmentally friendly PC borrowed many components from the [[ThinkPad]] line and was composed of recycled plastics, designed to be easily recycled at the end of its life, and used very little power.

The IBM PS/2 '''''Server''' 195'' and ''295'' (IBM 8600) were 486-based dual-bus MCA network [[server computer|server]]s supporting [[asymmetric multiprocessing]], designed by [[Parallan Computer|Parallan Computer Inc]].

The IBM ''PC Server 720'' (IBM 8642) was the largest MCA-based server made by IBM, although it was not, strictly speaking, a PS/2 model. It could be fitted with up to six Intel Pentium processors interconnected by the [[Corollary C-bus]] and up to eighteen SCSI hard disks. This model was equipped with seven combination MCA/[[Peripheral Component Interconnect|PCI]] slots.

=== PS/2 portables, laptops and notebooks ===
{{Main|IBM PS/2 portable computers|IBM PS/2 Note and PS/note}}[[File:IBM PS2 N33.jpg|thumb|PS/2 N33SX laptop (1992)]]
IBM also produced several '''portable and [[laptop]] PS/2s''', including the ''[[IBM PS/2 Model L40 SX|Model L40]]'' (ISA-bus 386SX), ''N33'' (IBM's first notebook-format computer from year 1991, Model 8533, 386SX), ''N51'' (386SX/SLC), ''P70'' (386DX) and ''P75'' (486DX2).

The IBM ''ThinkPad 700C'', aside from being labeled "700C PS/2" on the case, featured MCA and a 486SLC CPU.

===6152 Academic System===
{{See also|IBM ROMP|IBM RT PC}}
The 6152 Academic System was a [[Workstation|workstation computer]] developed by IBM's Academic Information Systems (ACIS) division for the university market introduced in February 1988. The 6152 was based on the PS/2 Model 60, adding a RISC Adapter Card on the [[Micro Channel]] bus. This card was a co-processor that enabled the 6152 to run [[IBM ROMP|ROMP]] software compiled for IBM's [[Academic Operating System]] (AOS), a version of [[BSD UNIX]] for the ROMP that was only available to select colleges and universities.<ref>{{cite magazine |last=LaPlante |first=Alice |date=1988-02-08 |title=Workstation Merges PS/2, RT Technology |magazine=InfoWorld |volume=10 |issue=6 |pages=1, 81}}</ref>

The RISC Adapter Card contained the ROMP-C microprocessor (an enhanced version of the ROMP that first appeared in the [[IBM RT PC]] workstations), a [[memory management unit]] (the ROMP had [[virtual memory]]), a [[Floating-point unit|floating-point]] [[coprocessor]], and up to 8{{nbsp}}MB of memory for use by the ROMP.<ref>{{cite book |author=<!--Staff writer(s)--> |title=IBM Academic System 6152: Quick Reference and Reference Diskette |date=January 1988 |page=2}}</ref> The 6152 was the first computer to use the ROMP-C, which would later be introduced in new RT PC models.<ref>{{cite magazine |author=The University of Michigan Computing Center |year=c. 1988 |title=UNIX Notes |magazine=U-M Computing News |volume=3 |page=19}}</ref>