IBM was struggling in 1986 against Apple's Macintosh series, so IBM set out to create something that would defeat the Macintosh. IBM came up with a all-in-one similar to the Macintosh. However, the Model 25 & 30 were the low-end (budget) models of the PS/2 range.
The PS/2 Model 25 became quite popular with businesses, but never made it strong with the home market.
The PS/2 Model 25 & 30 were the only system using the MCGA (Multicolor Graphics Adapter) standard. They came with this video features built-in. MCGA offered all text and graphic modes of the CGA standard plus 640x480 monochrome and 320x200, 256 colors (out of a palette of 262,144). It announced the future VGA standard which will become much more popular.
Model 25 & 30 were also the only PS/2 systems using an 8-bit ISA bus (like PC ATs), as opposed to other PS/2 models which used a 16 or 32 bit MCA bus.
Thanks to Alex Rushing for info and picture
Further information from Brandon:
The model 25 came in two models, a monochrome model, and a color model. The monochrome model usually is called "Type 001", the color one being "Type 004".. There never was a type 002, or 003.
The motherboard for the color and black and white models are exactly the same, minus some revisions on the later years. They were always surface mounted though (most of the chips anyway).
They are a tough machine, though when you install one in a new room, it NEEDS to let sit in the room for a couple hours, otherwise the power supply/motherboard will die.
While the floppy drives were 720KB, they "could" use 1.44MB drives, as long as the interface was the same.
They contain TWO BIOS's in them. One called the CBIOS, and the other called the ABIOS.. CBIOS is "Compatible BIOS", and is used for DOS or Windows 3.0 and under... ABIOS, or "Advanced BIOS", is used when it runs OS/2.. OS/2 is the native OS to this unit. They also had an option for a hard drive.
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I bought one of these in 1988. Mine had two floppy drives and no hard disk. It came with a copy of Windows 1.1 that was on three floppy disks. I normally used DOS, but did get it running on Windows to test it out. Only Word Perfect wouldn’t run on Windows. Called Word Perfect Tech Support to see if I could run it under Windows and they told me not to bother. Windows would never go anywhere they said. Just use DOS. Hilarious. A couple of years before Microsoft Word replaced Word Perfect as the most popular word processor and they went out of business. Ran “Quattro” as a spreadsheet program. $90 knock off of Lotus 1-2-3, before Excel took over. This machine cost about $2,000 in 1988 dollars!
Thursday 21st January 2021
Peter Gaylord (USA)
I *suspect* we had a setup of these in the early 90s at my elementary school in the Chicago suburbs. I always wondered what the mainframe setup was. It seemed like the computers themselves were used more like ANSI terminals to the mainframe than actually running software locally.
Friday 21st August 2020
Chris S. (Illinois, USA)
To Anthony in MISSOURI, I meant! (Sorry, I was still thinking about the wild card game the Brewers should have won!)
Monday 21st October 2019
Bob (USA)
NAME
PS/2 Model 25
MANUFACTURER
IBM
TYPE
Professional Computer
ORIGIN
U.S.A.
YEAR
august 1987
END OF PRODUCTION
Unknown
KEYBOARD
Full stroke keyboard, PS/2 type
CPU
Intel 8086
SPEED
8 MHz
CO-PROCESSOR
optional Intel 8087 (math co-processor)
RAM
512 KB, upgradable to 640 KB
VRAM
Unknown
ROM
Unknown
TEXT MODES
Unknown
GRAPHIC MODES
MCGA graphics : 640 x 480 in monochrome, 320 x 200 in 256 colours
COLORS
262 144 colours palette
SOUND
Internal PC buzzer
SIZE / WEIGHT
Unknown
I/O PORTS
Parallel port, 9pin serial port, 2 x ps/2 ports, 2 x internal expansion slots (8-bit)
