IBM PS/2 Model 35 SX

IBM Personal System/2 (PS/2)

Company type	Product line
Industry	Computer hardware
Predecessor	IBM PC
Founded	1987 (1987)
Products	Personal computers (desktop, tower, all-in-one, portable, laptop, notebook)
Owner	International Business Machines Corporation (IBM)
Website	www.ibm.com

The Personal System/2 (PS/2) represented a series of personal computers created by International Business Machines Corporation (IBM). Launched in 1987, the PS/2 marked IBM's second generation of personal computing devices, succeeding the original IBM PC lineup, which was discontinued following the PS/2 introduction in April 1987. The majority of PS/2 units incorporated IBM's proprietary Micro Channel architecture bus—a strategic move to reassert influence over the PC industry. Nevertheless, certain entry-level PS/2 variants continued to employ the commonly replicated ISA bus found in earlier models. The PS/2 family encompassed a range of configurations including desktop systems, tower units, integrated all-in-one computers, portable models, laptops, and notebooks.

Notes

Legend

Clarifications

• Submodels identified by IBM part numbers (P/N) for sales outside North America are not included.
• Unless specified otherwise, built-in or optional displays are CRT monitors.
• The Space Saving Keyboard is a compact 87-key version of the Model M, omitting the numeric keypad.
• The Model 25 Collegiate was designed for university students, featuring dual 720 KB floppy drives, maximum RAM capacity of 640 KB, and bundled with the official PS/2 Mouse, Windows 2.0, plus four blank floppy disks.
• Financial workstation variants incorporated a specialized 50-key function keypad tailored for banking tasks.
• LS ("LAN Station") models functioned as diskless workstations without local floppy or hard drives, connecting through Ethernet or Token Ring network adapters.
• Ultimedia editions were equipped with microphones and included SCSI CD-ROM drives, M-Audio sound cards, volume control knobs, along with front-facing headphone and microphone ports.
• Array models served as PS/2 Servers featuring support for RAID configurations.

Primary Series

IBM PS/2 model lineup

Model	IBM P/N	Processor	Clock speed (MHz)	Bus	Expansion slots	Drive bays	FDD	HDD	Standard RAM	Maximum RAM	Video adapter	Monitor	Form factor	Release date	Notes	Ref(s).
25	8525-001	Intel 8086	8 (0 w)	ISA, 8-bit	2	2	one 720 KB	none	512 KB	640 KB	MCGA	12-inch monochrome	All-in-one	Template:Date table sorting	Space Saving Keyboard included
25	8525-004	Intel 8086	8 (0 w)	ISA, 8-bit	2	2	one 720 KB	none	512 KB	640 KB	MCGA	12-inch color display	All-in-one	Template:Date table sorting	Space Saving Keyboard included

PS/2 Server

IBM PS/2 Server variants

Model	IBM P/N	CPU	Clock rate (MHz)	Bus type	Expansion slots	Drive bays	FDD	HDD	Base RAM	Max RAM	Graphics adapter	Display	Chassis type	Release date	Remarks
Server 85	9585-0X6	Intel 486SX	33	MCA, 32-bit	8	7	one 2.88 MB	104 MB (SCSI)	8 MB	64 MB	SVGA	optional	Tower	Template:Date table sorting
Server 85	9585-0X9	Intel 486SX	33	MCA, 32-bit	8	7	one 2.88 MB	160 MB (SCSI)	8 MB	64 MB	SVGA	optional	Tower	Template:Date table sorting
Server 85	9585-0XA	Intel 486SX	33	MCA, 32-bit	8	7	one 2.88 MB	208 MB/212 MB (SCSI)	8 MB	64 MB	SVGA	optional	Tower	Template:Date table sorting
Server 85	9585-0XD	Intel 486SX	33	MCA, 32-bit	8	7	one 2.88 MB	320 MB (SCSI)	8 MB	64 MB	SVGA	optional	Tower	Template:Date table sorting

Model	IBM P/N	CPU	Clock speed (MHz)	Bus type	Slots available	Drive bays count	Floppy drives	Hard drives	Default RAM size	Maximum RAM capacity	Video card	Display option	Case design	Launch date	Additional details
Further PS/2 Server configurations share similar features, including models with expanded hard disk storage up to one gigabyte (SCSI), enhanced RAM options reaching up to 256 megabytes, and processors spanning from Intel i486SX to Pentium. All utilize the Micro Channel architecture bus and support SVGA graphics adapters. The tower form factor is standard, with monitors offered optionally.
High-end and array models such as the Server 195 and Server 295 incorporate dual CPUs, RAID-5 support, hot-swappable drives totaling up to twenty-eight gigabytes, and increased expansion slots up to twelve. Certain premium versions came preloaded with operating systems like IBM LAN Server or Novell NetWare.

Portables

IBM PS/2 portable computer models

Model	IBM P/N	Processor type	Frequency (MHz)	Bus architecture	Expansion slots count	Drive bays count	FDD	HDD	Standard RAM	Maximum RAM	Graphics adapter	Display type	Form factor	Introduction date	Remarks
P70	8573-031	Intel 386	16	MCA, 32-bit	2 (one 16-bit, one 32-bit)	0	one 1.44 MB	30 MB (ESDI)	2 MB	8 MB	VGA	Monochrome gas plasma	Portable	Template:Date table sorting	Slot available for optional i387 coprocessor
P70	8573-061	i386	20	MCA, 32-bit	2 (one each of 16-bit and 32-bit)	0	one 1.44 MB	60 MB (ESDI)	2 MB	8 MB	VGA	Monochrome gas plasma	Portable	Template:Date table sorting	Optional slot for i387 coprocessor included
IBM PS/2 P70	8573-121	i386	20	style="background:#CCF" MCA,32-bit	2 (one16-bit, one32-bit)	0	one1.44MB	120MB (ESDI)	2MB	8MB	VGA	Monochrome gas plasma	Portable	\{\{date table sorting\} \}1989,05	\ Slot for optional i387 co-processor
\[[IBM PS/2 P75\|\ P75\]\]	\8573-161	\[[i486\|\ Intel\ i486\]\]	\33	\style="background:#CCF"\ MCA,\32-bit	\4 (two16-bit, two32-bit)	\0	\one1.44MB	\160MB (SCSI)	\4MB	\16MB	\VGA	\Monochrome gas plasma	\Portable	\{\{date table sorting\}\}1990,11	"SCSI controller integrated on planar board"
\[[IBM PS/2 P75\]\]	\8573-401	\[[i486\]\ Intel\ i486\]\]	\33	\style="background:#CCF"\ MCA,\32-bit	\4 (two16-bit, two32-bit)	\0	\one1.44MB	\400MB (SCSI)	\4MB	\16MB	\VGA	\Monochrome gas plasma	\Portable	\{\{date table sorting\}\}1990,11	"SCSI controller integrated on planar board"
\[[IBM PS/2 Model L40 SX\]\]	\8543-A44	\[[i386SX\]\ Intel386SX\]\]	\20	\style="background:#CFC"\ ISA,\16-bit	\0 (1 with AT bus expansion port)	\0	\one1.44MB	\60MB (IDE)	\2MB	\18MB	\VGA	\Monochrome LCD	\Laptop	\{\{date table sorting\}\}1991,03
\[[IBM PS/2 N51SX\]\]	\8551-033	\[[i386SX\]\]	\16	\style="background:#FFC"\ Proprietary	\2 (PC Card)	\unknown	\one1.44MB	\40MB (IDE)	\2MB	\10MB	\VGA	\Monochrome LCD	\Notebook	\unknown
\[[IBM PS/2 N51SLC\]\]	\8551-025	\[[IBM386SLC\]\]	\16	\style="background:#FFC"\ Proprietary

Related systems

IBM PS/2-associated models

Model	IBM P/N	CPU	Operating frequency (MHz)	Bus type	Number of slots	Number of drive bays	FDD	HDD	Base RAM	Maximum RAM	Graphics adapter	Display	Chassis type	Release date	Remarks
Academic System	6152-022	Intel 80286 ROMP 032	10 (286)	MCA, 16-bit	8	4	single 1.44 MB	20 MB (ST-506)	2 MB	8 MB	VGA	optional	Tower	Template:Date table sorting	Includes ROMP processor on daughterboard; cannot operate simultaneously with 286
Academic System	6152-024	Intel 80286 ROMP 032	10 (286)	MCA, 16-bit	8	4	single 1.44 MB	20 MB (ST-506)	4 MB	8 MB	VGA	optional	Tower	Template:Date table sorting	Equipped with ROMP processor on daughterboard; cannot run concurrently with 286
Academic System	6152-044	Intel 80286 ROMP 032	10 (286)	MCA, 16-bit	8	4	single 1.44 MB	44 MB (ST-506)	4 MB	8 MB	VGA	optional	Tower	Template:Date table sorting	Features ROMP processor on daughterboard; operation not parallel with 286 processor
Academic System	6152-048	Intel 80286 ROMP 032	10 (286)	MCA, 16-bit	8	4	single 1.44 MB	44 MB (ST-506)	8 MB	8 MB	VGA	optional	Tower	Template:Date table sorting	Contains ROMP processor on daughterboard; cannot be used simultaneously with the 286 CPU

... [Table continues similarly for EduQuest series, Industrial Computers, Personal Typing Systems, and others, trimmed proportionally for brevity]

Model	IBM P/N	CPU	Frequency (MHz)	Bus type	Slots count	Drive bays count	FDD type	HDD type	Default RAM size	Maximum RAM size	Video adapter type	Display option	Case style	Launch date	Comments
Academic System	6152-074	Intel 80286 ROMP 032	10 (286)	style="background:#CEF"|Micro Channel architecture,16-bit	8	4	one1.44MB	70MB (ESDI)	4MB	8MB	Video Graphics Array	optional	Tower		ROMP processor on daughterboard; incompatible with simultaneous operation alongside the286 CPU
Academic System	6152-078	Intel80286 ROMP032	10 (286)	style="background:#CEF"|Micro Channel architecture,16-bit	8	4	one1.44MB	70MB (ESDI)	8MB	8MB	Video Graphics Array	optional	Tower		Incorporates ROMP processor on daughterboard; does not support concurrent functionality with the286 processor
Clinical Workstation	7690	Intel8086	8 (0 wait states)	style="background:#FCC"|Industry Standard Architecture,8-bit	4	0	one1.44MB	none	640KB	8MB	Multi-Color Graphics Array (MCGA)	Monochrome LCD	Mobile workstation		Designed specifically for healthcare applications; pairs with IBM7496 Executive Workstation.

See also

• List of third-party Micro Channel computers
• List of IBM Personal Computer models