IBM PS/2 Model 25 SX
| Company type | Product line |
|---|---|
| Industry | Computer hardware |
| Predecessor | IBM Personal Computer XT, IBM Personal Computer AT (compatibility) |
| Founded | August 4, 1987 |
| Founder | International Business Machines Corporation (IBM) |
| Fate | Discontinued |
| Successor | Later PS/2 models with Micro Channel architecture |
| Headquarters | Boca Raton , United States |
Area served | United States |
Key people | José García (Boca Raton plant) |
| Products | Personal computers (Model 25, 25 286, 25 SX) |
| Owner | IBM |
| Parent | IBM Personal System/2 series |
The Personal System/2 Model 25 and its variants—the 25 286 and 25 SX—serve as IBM's budget-friendly options within the Personal System/2 series. Similar to the Model 30, the Model 25 employs an Industry Standard Architecture bus, allowing compatibility with expansion cards from earlier IBM PC models (IBM Personal Computer XT and IBM Personal Computer AT), but it is not compatible with the advanced PS/2 models utilizing Micro Channel architecture. Distinctive among PS/2 computers, the Model 25 lineup incorporates an all-in-one configuration that combines the CRT display and system components into a single unit. IBM primarily designed this series for home office environments and student users.
Development and release
Introduced on August 4, 1987, the Model 25 was the fifth addition to IBM’s PS/2 family. It features an Intel 8086 processor clocked at 8 MHz, effectively doubling the speed of the original IBM PC. The Collegiate edition, aimed at students, came equipped with dual 720 KB floppy drives, up to 640 KB of RAM, the official PS/2 Mouse, Windows 1.04, and four blank floppy disks.
In 1990, IBM refreshed the lineup by releasing the Model 25 286, which upgraded the processor to an Intel 80286 running at 10 MHz. Later, by late 1991, IBM’s Boca Raton plant under José García introduced the Model 25 SX featuring a more advanced Intel 80386SX processor operating at 20 MHz. This iteration was specifically intended for K–12 educational institutions. The Model 25 series was marketed exclusively within the United States.
At launch, IBM did not offer or support hard disk drives for the original Model 25; however, third-party hard drive solutions became available by late 1987. Subsequent versions—the 25 286 and 25 SX—provided optional hard drive upgrades.
Reception
Several reviewers from the period drew comparisons between the Model 25 and Apple's original Compact Macintosh. Stephen Satchell of InfoWorld observed that while its initial design resembled a distorted Macintosh, it eventually aligned more closely with other PS/2 models’ aesthetics. David E. Sanger from The New York Times regarded it as "perhaps the most attractive computer" IBM created for casual users, though he considered it "somewhat overpriced," yet still "relatively affordable for an IBM product." Both Sanger and Gus Venditto of PC Magazine criticized the absence of an integrated hard disk drive. Venditto pointed out that aftermarket hard drives were physically too large to fit within the Model 25’s two floppy drive bays and noted that IBM had not announced any official hard drive options. He also mentioned that one ISA slot was partially blocked by the CRT monitor, restricting expansion card size. Despite these drawbacks, Venditto commended the robust chassis construction and described it as a "well-built, fast computer ideal for environments where space is limited."
Submodels
| Model | IBM Part Number | Processor | Clock Speed |
Bus Type | Number of slots |
Number of Drive Bays |
Floppy Drives | Hard Drive | Base RAM | Maximum RAM | Video Adapter | Display | Form Factor | Launch Date | Additional Features | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 25 | 8525-001 | Intel 8086 | 8 MHz | ISA, 8-bit | 2 | 2 | one 720 KB | none | 512 KB | 640 KB | MCGA | 12-inch monochrome | All-in-one | Space Saving Keyboard | ||
| 25 | 8525-004 | Intel 8086 | 8 MHz | ISA, 8-bit | 2 | 2 | one 720 KB | none | 512 KB | 640 KB | MCGA | 12-inch color | All-in-one | Space Saving Keyboard | ||
| 25 Collegiate | 8525-C02 | Intel 8086 | 8 MHz | ISA, 8-bit | 2 | 2 | two 720 KB | none | 640 KB | 640 KB | MCGA | 12-inch monochrome | All-in-one | Space Saving Keyboard | ||
| 25 Collegiate | 8525-C05 | Intel 8086 | 8 MHz | ISA, 8-bit | 2 | 2 | two 720 KB | none | 640 KB | 640 KB | MCGA | 12-inch color | All-in-one | Space Saving Keyboard | ||
| 25 LS | 8525-L01 | Intel 8086 | 8 MHz | ISA,8-bit | 2 | 2 | one 720 KB | none | 512 KB | 640 KB | MCGA | 12-inch monochrome | All-in-one | Token Ring | ||
| 25 LS | 8525-L04 | Intel 8086 | 8 MHz | ISA,8-bit | 2 | 2 | one720 KB | none | 512 KB | 640 KB | MCGA | 12-inch color | All-in-one | Token Ring | ||
| 25 286 | 8525-006 | Intel80286 | 10 MHz | Industry Standard Architecture ISA,16-bit | 2 | 2 | one1.44 MB | none | 1 MB | 4 MB | Video Graphics Array VGA | 12-inch color | All-in-one |
Space Saving Keyboard |
||
| 25 SX | 8525-K00 | Intel386SX | 20 MHz | Industry Standard Architecture ISA,16-bit | 3 | 2 | one1.44 MB | none | 1 MB | 16 MB | Video Graphics Array VGA | 12-inch color | All-in-one |