IBM PS/2 Model 25 explained

Personal System/2 Model 25
Developer:International Business Machines Corporation (IBM)
Manufacturer:IBM
Family:Personal System/2
Type:Personal computer
Power:120/240 VAC
Related:List of IBM PS/2 models

The Personal System/2 Model 25 and its later submodels the 25 286 and 25 SX are IBM's lowest-end entries in the Personal System/2 (PS/2) family of personal computers. Like its sibling the Model 30, the Model 25 features an Industry Standard Architecture bus, allowing it to use expansion cards from its direct predecessors, the PC/XT and the PC/AT—but not from higher entries in the PS/2 line, which use Micro Channel. Unlike all other entries in the PS/2 line, the Model 25 and its submodels are built into an all-in-one form factor, with its cathode-ray tube (CRT) monitor and system board occupying the same enclosure. IBM oriented the Model 25 at home office workers and students.

Development and release

IBM unveiled the Model 25 on August 4, 1987. It is the fifth entry of the Personal System/2 range. The first Model 25 is powered by an Intel 8086 running at 8 MHz, roughly twice the speed of the original IBM Personal Computer.[1] A college student-oriented version of the Model 25, the Collegiate, has two 720 KB floppy drives, with a maximum RAM capacity of 640 KB, and was packaged with the official PS/2 Mouse, Windows 2.0, and four blank floppy disks.

In 1990, IBM released the Model 25 286, which upgrades the original to an Intel 80286 running at 10 MHz.[2] In late 1991, IBM's Boca Raton facility, led by José García, developed the Model 25 SX, which features an Intel 80386SX clocked at 20 MHz. This version of the Model 25 was sold only to K–12 schools.[3] The Model 25 series was never officially sold outside of the United States.[4]

IBM neither included nor supported hard disk drives in the original Model 25, although several aftermarket kits were available by late 1987.[5] The later 25 286 and 25 SX were sold with a hard drive as an option.

Reception

Multiple contemporary reviewers compared the Model 25 to Apple's original Macintosh.[6] [7] [8] Stephen Satchell of InfoWorld wrote when he first saw the Model 25 on its announcement: "[M]y immediate impression was that I was looking at a deformed Macintosh. When the stage lights came up, the illusion was shattered and I saw the similarity to the rest of the PS/2 line."[9]

David E. Sanger of The New York Times called the computer perhaps "the most attractive computer" that IBM had ever designed for people who only used their computer for up to a couple hours a day and while a "touch overpriced," it was "relatively inexpensive for an IBM." Sangler and Gus Venditto of PC Magazine were frustrated by the Model 25's lack of a built-in hard disk drive. Venditto wrote that, on launch, contemporary aftermarket hard drives were too large to be installed in either of the computer's two floppy drive bays—with no announcements for a hard drive solution for the Model 25 on the horizon. He also observed that the space for the top ISA slot on the riser is partially obstructed by the CRT monitor, preventing full-height cards from fitting into that slot. On the whole, he appreciated the sturdily built chassis and concluded that the Model 25 was a "well-crafted, fast computer for places where real estate is at a premium."

Submodels

See also: List of IBM PS/2 models.

+ IBM PS/2 Model 25 submodelsModel IBM Processor Clock speed
Bus No. of
drive bays 		Stock
Maximum
Video adapter Monitor Form factor Date introduced Notes
258525-001Intel 80868 (0)ISA, 8-bit22one 720 KBnone512 KB640 KBMCGA12-in. monochromeAll-in-oneSpace Saving Keyboard[10]
258525-004Intel 80868 (0)ISA, 8-bit22one 720 KBnone512 KB640 KBMCGA12-in. colorAll-in-oneSpace Saving Keyboard
258525-G01Intel 80868 (0)ISA, 8-bit22one 720 KBnone512 KB640 KBMCGA12-in. monochromeAll-in-one[11]
258525-G04Intel 80868 (0)ISA, 8-bit22one 720 KBnone512 KB640 KBMCGA12-in. colorAll-in-one
25 Collegiate8525-C02Intel 80868 (0)ISA, 8-bit22two 720 KBnone640 KB640 KBMCGA12-in. monochromeAll-in-oneSpace Saving Keyboard[12]
25 Collegiate8525-C05Intel 80868 (0)ISA, 8-bit22two 720 KBnone640 KB640 KBMCGA12-in. colorAll-in-oneSpace Saving Keyboard
25 Collegiate8525-K02Intel 80868 (0)ISA, 8-bit22two 720 KBnone640 KB640 KBMCGA12-in. monochromeAll-in-one
25 Collegiate8525-K05Intel 80868 (0)ISA, 8-bit22two 720 KBnone640 KB640 KBMCGA12-in. colorAll-in-one
25 LS8525-L01Intel 80868 (0)ISA, 8-bit22one 720 KBnone512 KB640 KBMCGA12-in. monochromeAll-in-oneToken Ring
25 LS8525-L04Intel 80868 (0)ISA, 8-bit22one 720 KBnone512 KB640 KBMCGA12-in. colorAll-in-oneToken Ring
25 2868525-006Intel 8028610 (1)ISA, 16-bit22one 1.44 MBnone1 MB4 MBVGA12-in. colorAll-in-oneSpace Saving Keyboard[13]
25 2868525-036Intel 8028610 (1)ISA, 16-bit22one 1.44 MB30 MB 1 MB4 MBVGA12-in. colorAll-in-one
25 2868525-G06Intel 8028610 (1)ISA, 16-bit22one 1.44 MBnone1 MB4 MBVGA12-in. colorAll-in-oneSpace Saving Keyboard
25 2868525-G36Intel 8028610 (1)ISA, 16-bit22one 1.44 MB30 MB 1 MB4 MBVGA12-in. colorAll-in-one
25 SX8525-K00Intel 386SX20ISA, 16-bit32one 1.44 MBnone1 MB16 MBVGA12-in. colorAll-in-one[14]
25 SX8525-K01Intel 386SX20ISA, 16-bit32one 1.44 MBnone1 MB16 MBVGA12-in. colorAll-in-oneEthernet
25 SX8525-L02Intel 386SX20ISA, 16-bit32one 1.44 MBnone1 MB16 MBVGA12-in. colorAll-in-oneToken Ring

Notes and References

  1. Hillkirk . John . Mark Lewyn . August 4, 1987 . Tandy, IBM target school, home market . USA Today . Gannett Company . 1B . ProQuest.
  2. Marburg . Robert . December 24, 1990 . IBM debates AT-bus PS/2 plans for '91 . PC Week . Ziff-Davis . 7 . 51 . 6 . Gale.
  3. News: Lunan. Charles. January 1992. IBM Goes After School Computer Market. Sun Sentinel. Tribune Publishing Company. D3. ProQuest. On Tuesday, IBM released the first product developed by [Jose] Garcia's team: the Model 25 SX. The new model uses the same Intel 386SX microprocessor ... to run the graphics-rich software popular with teachers. It will be able to display up to 256 different colors and come standard with connections for overhead projection systems and computer networks. IBM said the new models would become available in April at $1,249 to $1,899..
  4. Staff writer . May 11, 1990 . IBM adds pricey 80286-based PS/2 model 25 in US . . GlobalData . 1423 . Gale.
  5. Willmott . Donald P. . December 8, 1987. Hard Disk Power for the Model 25 . PC Magazine . Ziff-Davis . 6 . 21 . 328 . Google Books.
  6. Sanger . David E. . August 9, 1987 . I.B.M. Learns from the Macintosh . The New York Times . A12 . ProQuest.
  7. Freiberger . Paul . John Markoff . October 13, 1987 . Apple's Mac emerges as most influential PC . Montreal Gazette . G1 . ProQuest.
  8. Venditto . Gus . September 29, 1987 . PS/2 Model 25 Looks Like a Mac, Runs Like a Model 30 . PC Magazine . Ziff-Davis . 6 . 16 . 33–34 . Google Books.
  9. Satchell . Stephen . August 17, 1987 . Short Looks: IBM PS/2 Model 25 . InfoWorld . IDG Publications . 9 . 33 . 44 . Google Books.
  10. Web site: IBM PS/2 (Model 25) – Technical Specifications. International Business Machines Corporation. Ardent Tool. 2000. September 28, 2021.
  11. Web site: IBM Personal System/2 and IBM Personal Computer Product Reference, Version 4.0. September 1988. International Business Machines Corporation. September 29, 2021. 44. Bitsavers.
  12. Web site: IBM Personal System/2 and IBM Personal Computer Product Reference, Version 4.0. September 1988. International Business Machines Corporation. September 29, 2021. 43. Bitsavers.
  13. Web site: IBM PS/2 (Model 25-286) – Technical Specifications. International Business Machines Corporation. Ardent Tool. 2000. September 28, 2021.
  14. Web site: Walsh. William. June 15, 2005. IBM PS/2 Model 25SX. Walsh Computer Technology. September 29, 2021.

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