IBM PS/2

The Personal System/2 or PS/2 is

The PS/2 line was created by IBM partly in an attempt to recapture control of the PC market by introducing the advanced yet proprietary Micro Channel architecture (MCA) on higher-end models. These models were in the strange position of being incompatible with the hardware standards previously established by IBM and adopted in the IBM PC compatible industry. IBM's initial PS/2 computers were popular with target market corporate buyers, and by September 1988, IBM reported that it had sold 3 million PS/2 machines. This was only 18 months after the new range had been introduced.

Most major PC manufacturers balked at IBM's licensing terms for MCA-compatible hardware, particularly the per-machine royalties. In 1992, Macworld stated that "IBM lost control of its own market and became a minor player with its own technology."^[5] IBM officially retired the PS/2 line in July 1995.^[6]

The

Technology

IBM's PS/2 was designed to remain software compatible with their PC/AT/XT line of computers upon which the large

With certain models to the IBM PS/2 line,

Bus mastering capability, bus arbitration, and a primitive form of plug-and-play management of hardware were all benefits of MCA. Gilbert Held in his 2000 book Server Management observes: "MCA used an early (and user-hostile) version of what we know now as 'Plug-N′-Play', requiring a special setup disk for each machine and each card."^[9] MCA never gained wide acceptance outside of the PS/2.

When setting up the card with its disk, all choices for interrupts and other changes were accomplished automatically by the PC reading the old configuration from the floppy disk. This made necessary changes, then recorded the new configuration to the floppy disk. This meant that the user must keep that same floppy disk matched to that particular PC. For a small organization with a few PCs, this was annoying, but less expensive and time-consuming than bringing in a PC technician to do installation. But for large organizations with hundreds or even thousands of PCs, permanently matching each PC with its own floppy disk was a logistical nightmare. Without the original, (and correctly updated) floppy disk, no changes could be made to the PC's cards.

In addition to the technical setup, legally, royalties were required for each MCA-compatible machine sold. There was nothing unique in IBM insisting on payment of royalties on the use of its patents applied to Micro Channel-based machines. Up until that time, some companies had failed to pay IBM for the use of its patents on the earlier generation of Personal Computer.^{[citation needed]}

Keyboard/mouse

Layout

The PS/2 IBM

PS/2 systems introduced a new specification for the

Additionally, the PS/2 introduced a new software data area known as the Extended BIOS Data Area (EBDA). Its primary use was to add a new buffer area for the dedicated mouse port. This also required making a change to the "traditional" BIOS Data Area (BDA) which was then required to point to the base address of the EBDA.

Another new PS/2 innovation was the introduction of bidirectional parallel ports which, in addition to their traditional use for connecting a printer, could now function as a high-speed data transfer interface. This allowed the use of new hardware such as parallel port scanners, CD-ROM drives, and also enhanced the capabilities of printers by allowing them to communicate with the host PC and send back signals instead of simply being a passive output device.

Graphics

Most of the initial range of PS/2 models were equipped with a new

Key monitors and their maximum resolutions:

• 8504: 12″, 640 × 480, 60 Hz
  non-interlaced
  , 1991, monochrome
• 8507: 19″, 1024 × 768, 43.5 Hz
  interlaced
  , 1988, monochrome
• 8511: 14″, 640 × 480, 60 Hz
  non-interlaced
  , 1987
• 8512: 14″, 640 × 480, 60 Hz
  non-interlaced
  , 1987
• 8513: 12″, 640 × 480, 60 Hz
  non-interlaced
  , 1987
• 8514: 16″, 1024 × 768, 43.5 Hz
  interlaced
  , 1987
• 8515: 14″, 1024 × 768, 43.5 Hz
  interlaced
  , 1991
• 8516: 14″, 1024 × 768, 43.5 Hz
  interlaced
  , 1991
• 8518: 14″, 640 × 480, 75 Hz
  non-interlaced
  , 1992
• 9515: 14″, 1024 × 768, 43.5 Hz
  interlaced
  , 1992
• 9517: 16″, 1280 × 1024, 53 Hz
  interlaced
  , 1991
• 9518: 14″, 640 × 480,
  non-interlaced
  , 1992
• 38F4737: 10", 640 × 480,
  non-interlaced
  , 1989, amber monochrome plasma screen; this display was exclusive to models P70 and P75

In truth, all XGA 1024 × 768 monitors are multimode, as XGA works as an add-on card to a built-in VGA and transparently passes the VGA signal through when not operating in a high-resolution mode. All of the listed 85xx displays can therefore sync 640×480 at 60 Hz (or 720 × 400 at 70 Hz) in addition to any higher mode they may also be capable of. This however is not true of the 95xx models (and some unlisted 85xx's), which are specialist workstation displays designed for use with the XGA-2 or Image Adapter/A cards, and whose fixed frequencies all exceed that of basic VGA – the lowest of their commonly available modes instead being 640 × 480 at 75 Hz, if not something much higher still. It is also worth noting that these were still merely dual- or "multiple-frequency" monitors, not variable-frequency (also known as multisync); in particular, despite running happily at 640 × 480, 720 × 400 and 1024 × 768, an (e.g.) 8514 cannot sync the otherwise common intermediate 800 × 600 SVGA resolution, even at the relatively low 50 to 56 Hz refresh rates initially used.

Although the design of these adapters did not become an industry standard as VGA did, their 1024 × 768 pixel resolution was subsequently widely adopted as a standard by other manufacturers, and XGA became a synonym for this screen resolution. The only exceptions were the bottom-rung 8086-based Model 25 and 30, which had a cut-down version of VGA referred to as MCGA; the 286 models came with VGA. This supported CGA graphics modes, VGA 320 × 200 256 color and 640 × 480 monochrome mode, but not EGA or color 640 × 480.

VGA video connector

All of the new PS/2 graphics systems (whether MCGA, VGA, 8514, or later XGA) used a 15-pin

The VGA connector became the de facto standard for connecting monitors and projectors on both PC and non-PC hardware over the course of the early 1990s, replacing a variety of earlier connectors.

Storage

Apple had first popularized the 3.5" floppy on the Macintosh line and IBM brought them to the PC in 1986 with the

In the initial lineup, IBM used 720 KB double density (DD) capacity drives on the 8086-based models and 1440 KB high density (HD) on the 80286-based and higher models. By the end of the PS/2 line they had moved to a somewhat standardized capacity of 2880 KB.

The PS/2 floppy drives lacked a capacity detector. 1440 KB floppies had a hole so that drives could identify them from 720 KB floppies, preventing users from formatting the smaller capacity disks to the higher capacity (doing so would work, but with a higher tendency of data loss). Clone manufacturers implemented the hole detection, but IBM did not. As a result of this a 720 KB floppy could be formatted to 1440 KB in a PS/2, but the resulting floppy would only be readable by a PS/2 machine.^[11]

PS/2s primarily used Mitsubishi floppy drives and did not use a separate Molex power connector; the data cable also contained the power supply lines. As the hardware aged the drives often malfunctioned due to bad quality capacitors.^{[citation needed]}

The PS/2 used several different types of internal hard drives. Early models used

Many PS/2 models also used proprietary IBM SIMMs and could not be fitted with commonly available types. However industry standard SIMMs could be modified to work in PS/2 machines if the SIMM-presence and SIMM-type detection bridges, or associated contacts, were correctly rewired.^[citation needed]

Models

At launch, the PS/2 family comprised the Model 30, 50, 60 and 80;^[7] the Model 25 was launched a few months later.

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 MHz, 512 KB of RAM, and 720 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 MHz or 20 MHz 386 CPU, up to 12 MB of memory, IDE hard drive, VGA Monitor and 16 bit ISA slots making it the highest available model 25 available denoted by model number 8525-L41.

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 MB of RAM.

Later ISA PS/2 models comprised the

386SLC

processors.

The higher-numbered models (above 50) were equipped with the Micro Channel bus and mostly

Intel 486

processors, in a complex called the Power Platform.

The PS/2 Models 90 (IBM 8590/9590) and 95 (IBM 8595/9595/9595A) used Processor Complex

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 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

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

servers supporting asymmetric multiprocessing, designed by 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/PCI slots.

PS/2 portables, laptops and notebooks

See also:

IBM PS/2 Note

See also: IBM ROMP and IBM RT PC

The 6152 Academic System was a

BSD UNIX for the ROMP that was only available to select colleges and universities.^[13]

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 coprocessor, and up to 8 MB of memory for use by the ROMP.^[14] The 6152 was the first computer to use the ROMP-C, which would later be introduced in new RT PC models.^[15]

Marketing

During the 1980s, IBM's advertising of the original PC and its other product lines had frequently used the likeness of Charlie Chaplin. For the PS/2, however, IBM augmented this character with the following jingle:

How ya gonna do it?
PS/2 it!
It's as easy as IBM. (Or, "The solution is IBM.")

Another campaign featured actors from the television show M*A*S*H playing the staff of a contemporary (i.e. late-1980s) business in roles reminiscent of their characters' roles from the series. Harry Morgan, Larry Linville, William Christopher, Wayne Rogers, Gary Burghoff, Jamie Farr, and Loretta Swit were in from the beginning, whereas Alan Alda joined the campaign later.^[16]

The profound lack of success of these advertising campaigns led, in part, to IBM's termination of its relationships with its global advertising agencies; these accounts were reported by Wired magazine to have been worth over $500 million a year, and the largest such account review in the history of business.^[17]

Overall, the PS/2 line was largely unsuccessful with the consumer market, even though the PC-based Models 30 and 25 were an attempt to address that. With what was widely seen as a technically competent but cynical attempt to gain undisputed control of the market, IBM unleashed an industry backlash, which went on to standardize VESA, EISA and PCI. In large part, IBM failed to establish a link in the consumer's mind between the PS/2 MicroChannel architecture and the immature OS/2 1.x operating system; the more capable OS/2 version 2.0 did not release until 1992.^[18]

The firm suffered massive financial losses for the remainder of the 1980s, forfeiting its previously unquestioned position as the industry leader, and eventually lost its status as the largest manufacturer of personal computers, first to

Dell. From a high of 10,000 employees in Boca Raton before the PS/2 came out, only seven years later, IBM had $600 million in unsold inventory and was laying off staff by the thousands.^[19][20]

After the failure of the PS/2 line to establish a new standard, IBM was forced to revert to building ISA PCs—following the industry it had once led—with the low-end PS/1 line and later with the more compatible Aptiva and PS/ValuePoint lines.

Still, the PS/2 platform experienced some success in the corporate sector where the reliability, ease of maintenance and strong corporate support from IBM offset the rather daunting cost of the machines. Also, many people still lived with the motto "

Nobody ever got fired for buying an IBM". In the mid-range desktop market, the models 55SX and later 56SX were the leading sellers for almost their entire lifetimes.^{[citation needed}

] Later PS/2 models saw a production life span that took them into the late 1990s, within a few years of IBM selling off the division.

Timeline

Timeline of the IBM Personal Computer v t e
Asterisk (*) denotes a model released in Japan only

Notes

1. PS/2E
   on top of a Model 56 and a Model 30 286

References

1. ISBN 9780080938271. Archived
   from the original on 2023-04-25. Retrieved 2023-03-21 – via Google Books.
2. ^ Clancy, Heather (June 2, 1988). "IBM adds to second generation of personal computers". UPI. p. 219. Archived from the original on February 21, 2022. Retrieved February 21, 2022.
3. ^ IBM Personal System/2 Hardware Interface Technical Reference (PDF). IBM. May 1988. 68X2330. Archived from the original (PDF) on 2020-10-29. Retrieved 2016-11-26.
4. ^ "PS/2 Reference Manuals". MCA Mafia. 2006-03-04. Archived from the original on 2016-11-03. Retrieved 2016-11-26.
5. ^ Borrell, Jerry (May 1992). "Opening Pandora's Box". Macworld. pp. 21–22.
6. ^ Singh, Jai (April 10, 1995). "MCA, PS/2 bite the dust; OS/2 to follow?". InfoWorld. 17 (15): 3. Archived from the original on November 9, 2023. Retrieved August 17, 2021.
7. ^ ^{a b c d e} BYTE editorial staff (June 1987). "The IBM PS/2 Computers". BYTE. p. 100. Retrieved 5 November 2013.
8. ^ "Hardware Maintenance Manual" (PDF). mcamafia.de. March 1996. Archived (PDF) from the original on 25 April 2023. Retrieved 30 April 2023.
9. ISBN 978-1-4200-3106-5
   .
10. ^ Jim Porter (1998-12-14). "100th Anniversary Conference: Magnetic Recording and Information Storage" (PDF). disktrend.com. Archived from the original (PDF) on 2012-03-28. Retrieved 2014-03-24.
11. ^ Ohland, Louis. "floppy". ohlandl.ipv7.net. Archived from the original on 2011-07-23. Retrieved 2011-02-19.
12. ^ "The IBM PS/2: 25 Years of PC History". PCWorld. Archived from the original on 2018-10-04. Retrieved 2018-08-28.
13. ^ LaPlante, Alice (1988-02-08). "Workstation Merges PS/2, RT Technology". InfoWorld. Vol. 10, no. 6. pp. 1, 81.
14. ^ IBM Academic System 6152: Quick Reference and Reference Diskette. January 1988. p. 2.
15. ^ The University of Michigan Computing Center (c. 1988). "UNIX Notes". U-M Computing News. Vol. 3. p. 19.
16. ^ "M*A*S*H Cast Commercials - IMB PS/2". YouTube. Archived from the original on 2015-05-28. Retrieved 13 April 2014.
17. ^ Wired, Issue 3.08, August 1995
18. ^ McCracken, Harry (2 April 2012). "25 Years of IBM's OS/2: The Strange Days and Surprising Afterlife of a Legendary Operating System". Time. Archived from the original on 30 September 2015. Retrieved 29 September 2015 – via techland.time.com.
19. ^ "IBM in Boca Raton | First Personal Computer | Companies in Boca Raton". Archived from the original on 2017-11-07. Retrieved 2017-11-03.
20. ^ Vijayan, Jaikumar (August 1, 1994). "IBM cuts PC force, kills Ambra Corp". Computerworld. Vol. 28, no. 31. p. 4. Archived from the original on November 9, 2023. Retrieved August 7, 2022.

Further reading

• Burton, Greg. IBM PC and PS/2 pocket reference. NDD (the old dealer channel), 1991.
• Byers, T.J. IBM PS/2: A Reference Guide. Intertext Publications, 1989.
  ISBN 0-07-009525-6
  .
• Dalton, Richard and Mueller, Scott. IBM PS/2 Handbook . Que Publications, 1989.
  ISBN 0-88022-334-0
  .
• Held, Gilbert. IBM PS/2: User's Reference Manual. John Wiley & Sons Inc., 1989.
  ISBN 0-471-62150-1
  .
• Hoskins, Jim. IBM PS/2. John Wiley & Sons Inc., fifth revised edition, 1992.
  ISBN 0-471-55195-3
  .
• Leghart, Paul M. The IBM PS/2 in-depth report. Pachogue, NY: Computer Technology Research Corporation, 1988.
• Newcom, Kerry. A Closer Look at IBM PS/2 Microchannel Architecture. New York: McGraw-Hill, 1988.
• Norton, Peter. Inside the IBM PC and PS/2. Brady Publishing, fourth edition 1991.
  ISBN 0-13-465634-2
  .
• Outside the IBM PC and PS/2: Access to New Technology. Brady Publishing, 1992.
  ISBN 0-13-643586-6
  .
• Shanley, Tom. IBM PS/2 from the Inside Out. Addison-Wesley, 1991.
  ISBN 0-201-57056-4
  .

External links

Wikimedia Commons has media related to IBM Personal System/2.

• IBM Type 8530
• IBM PS/2 Personal Systems Reference Guide 1992 - 1995
• Computercraft - The PS/2 Resource Center
• Ardent Tool of Capitalism - covers all PS/2 models and adapters
• PS/2 keyboard pinout
• PS/2 Mouse/Keyboard Interfacing at the Wayback Machine (archived August 10, 2015)
• Computer Chronicles episode on the PS/2
• IBM PS/2 L40 SX (8543)