IBM PS/2 Model 25

IBM Personal System/2 Model 25
Personal System 2 Model 25.png
An original PS/2 Model 25
DeveloperInternational Business Machines
ManufacturerIBM
Product familyPersonal System/2
TypePersonal computer
Release dateAugust 4, 1987; 35 years ago (1987-08-04)
Media
  • 720 KB 3.5-in floppy disks (Model 25)
  • 1.44 MB 3.5-in floppy disks (Models 25 286 and 25 SX
CPU
Graphics
Power120/240 VAC ~

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.[2]

Development and release[]

Case badge on a Model 25 SX

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.[3] 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.[4]

In 1990, IBM released the Model 25 286, which upgrades the original to an Intel 80286 running at 10 MHz.[5] 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.[6] The Model 25 series was never officially sold outside of the United States.[7]

IBM neither included nor supported hard disk drives in the original Model 25, although several aftermarket kits were available by late 1987.[8] The later 25 286 and 25 SX were sold with a hard drive as an option.[7][9]

Reception[]

Multiple contemporary reviewers compared the Model 25 to Apple's original Macintosh.[2][10][11] 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."[4]

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."[2] Sangler and Gus Venditto of PC Magazine were frustrated by the Model 25's lack of a built-in hard disk drive.[2][11] 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."[11]

Submodels[]

IBM PS/2 Model 25 submodels
Model IBM P/N Processor Clock speed
(MHz)
Bus L2 cache
(KB)
No. of
slots
No. of
drive bays
FDD HDD Stock
memory
Monitor Form factor Date introduced Notes Ref(s).
25 8525-001 Intel 8086 8 (0 w) ISA, 8-bit 0 2 2 one 720 KB none 512 KB 12-in. monochrome All-in-one August 1987 Space Saving Keyboard [12]
25 8525-004 Intel 8086 8 (0 w) ISA, 8-bit 0 2 2 one 720 KB none 512 KB 12-in. color All-in-one August 1987 Space Saving Keyboard [12]
25 8525-G01 Intel 8086 8 (0 w) ISA, 8-bit 0 2 2 one 720 KB none 512 KB 12-in. monochrome All-in-one August 1987 [13]
25 8525-G04 Intel 8086 8 (0 w) ISA, 8-bit 0 2 2 one 720 KB none 512 KB 12-in. color All-in-one August 1987 [13]
25 LS 8525-L01 Intel 8086 8 (0 w) ISA, 8-bit 0 2 2 one 720 KB none 512 KB 12-in. monochrome All-in-one August 1987 Token Ring [13]
25 LS 8525-L04 Intel 8086 8 (0 w) ISA, 8-bit 0 2 2 one 720 KB none 512 KB 12-in. color All-in-one August 1987 Token Ring [13]
25 Collegiate 8525-C02 Intel 8086 8 (0 w) ISA, 8-bit 0 2 2 two 720 KB none 640 KB 12-in. monochrome All-in-one August 1987 Space Saving Keyboard [14]
25 Collegiate 8525-K02 Intel 8086 8 (0 w) ISA, 8-bit 0 2 2 two 720 KB none 640 KB 12-in. monochrome All-in-one August 1987 [14]
25 Collegiate 8525-C05 Intel 8086 8 (0 w) ISA, 8-bit 0 2 2 two 720 KB none 640 KB 12-in. color All-in-one August 1987 Space Saving Keyboard [14]
25 Collegiate 8525-K05 Intel 8086 8 (0 w) ISA, 8-bit 0 2 2 two 720 KB none 640 KB 12-in. color All-in-one August 1987 [14]
25 286 8525-006 Intel 80286 10 (1 w) ISA, 16-bit 0 2 2 one 1.44 MB none 1 MB 12-in. color All-in-one October 1990 Space Saving Keyboard [15]
25 286 8525-036 Intel 80286 10 (1 w) ISA, 16-bit 0 2 2 one 1.44 MB 30 MB 1 MB 12-in. color All-in-one October 1990 [15]
25 286 8525-G06 Intel 80286 10 (1 w) ISA, 16-bit 0 2 2 one 1.44 MB none 1 MB 12-in. color All-in-one October 1990 Space Saving Keyboard [15]
25 286 8525-G36 Intel 80286 10 (1 w) ISA, 16-bit 0 2 2 one 1.44 MB 30 MB 1 MB 12-in. color All-in-one October 1990
25 SX 8525-K00 Intel 80386SX 20 ISA, 16-bit 0 3 2 one 1.44 MB 1 MB 12-in. color All-in-one April 1992 [6][9]
25 SX 8525-K01 Intel 80386SX 20 ISA, 16-bit 0 3 2 one 1.44 MB 1 MB 12-in. color All-in-one April 1992 Ethernet [6][9]
25 SX 8525-L02 Intel 80386SX 20 ISA, 16-bit 0 3 2 one 1.44 MB 1 MB 12-in. color All-in-one April 1992 Token Ring [6][9]

References[]

  1. ^ Sandler, Corey; Donald Kennedy (1989). Insider's Guide to the IBM PS/2. Scott Foresman. p. 66. ISBN 9780673381712 – via Google Books.
  2. ^ a b c d Sanger, David E. (August 9, 1987). "I.B.M. Learns from the Macintosh". The New York Times: A12 – via ProQuest.
  3. ^ Hillkirk, John; Mark Lewyn (August 4, 1987). "Tandy, IBM target school, home market". USA Today. Gannett Company: 1B – via ProQuest.
  4. ^ a b Satchell, Stephen (August 17, 1987). "Short Looks: IBM PS/2 Model 25". InfoWorld. IDG Publications. 9 (33): 44 – via Google Books.
  5. ^ Marburg, Robert (December 24, 1990). "IBM debates AT-bus PS/2 plans for '91". PC Week. Ziff-Davis. 7 (51): 6 – via Gale.
  6. ^ a b c d Lunan, Charles (January 1992). "IBM Goes After School Computer Market". Sun Sentinel. Tribune Publishing Company. p. D3 – via 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.
  7. ^ a b Staff writer (May 11, 1990). "IBM adds pricey 80286-based PS/2 model 25 in US". Computergram International. GlobalData (1423) – via Gale.
  8. ^ Willmott, Donald P. (December 8, 1987). "Hard Disk Power for the Model 25". PC Magazine. Ziff-Davis. 6 (21): 328 – via Google Books.
  9. ^ a b c d Walsh, William (June 15, 2005). "IBM PS/2 Model 25SX". Walsh Computer Technology. Retrieved September 29, 2021.
  10. ^ Freiberger, Paul; John Markoff (October 13, 1987). "Apple's Mac emerges as most influential PC". Montreal Gazette: G1 – via ProQuest.
  11. ^ a b c 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 – via Google Books.
  12. ^ a b "IBM PS/2 (Model 25) – Technical Specifications". International Business Machines. 2000. Retrieved September 28, 2021 – via Ardent Tool.
  13. ^ a b c d "IBM Personal System/2 and IBM Personal Computer Product Reference, Version 4.0" (PDF). International Business Machines. September 1988. p. 44. Retrieved September 29, 2021 – via Bitsavers.
  14. ^ a b c d "IBM Personal System/2 and IBM Personal Computer Product Reference, Version 4.0" (PDF). International Business Machines. September 1988. p. 43. Retrieved September 29, 2021 – via Bitsavers.
  15. ^ a b c "IBM PS/2 (Model 25-286) – Technical Specifications". International Business Machines. 2000. Retrieved September 28, 2021 – via Ardent Tool.