An IBM PS/2 model 30 entered the collection, exactly the 8530-021 model, which I bought on eBay. The computer didn't work well, so it was sold to me at a good price.
The IBM PS/2 Model 30 is an entry-level desktop, manufactured by International Business Machines Corporation (IBM) since 1987.
There are several versions of IBM PS/2 model 30. Mine, the 8530-021, is equipped with an Intel 8086 processor at 8MHz.
The standard operating system is IBM PC DOS version 3.30. For data storage media, the IBM PS/2 model 30 is equipped with one (or two) internal floppy disk drives, 3.5", 720KB. Instead of the second floppy you can install the hard disk.
Upon arrival, the computer was in good cosmetic condition. It had no hard drive, keyboard, mouse and monitor. In addition, the RAM was damaged: the diagnostic test at power on counted only 128KB of RAM instead of the correct 640KB.
I did some simple work on the computer. First I cleaned it well. Despite the cleaning... a bit of a moldy smell remained, which cannot be removed. I purchased and replaced the 30-pin, 256KB SIMMs. In this way, the RAM works correctly and, also counting the 128KB already soldered on the motherboard, the count is now correct: 640KB. I purchased a 20MB IBM WDI-325Q hard disk to complete the computer. The hard disk connector is proprietary and it is not possible to install other hard disks with IDE or similar connectors.
I also replaced the batteries, which were starting to leak acid, with a 3V lithium flat.
Startup screen
The computer starts with diagnostic tests. Many tests are not visible on the monitor, which only shows the progress of the RAM test.
After the initial self-test, the computer searches for a startup disk (floppy floppy disk or hard disk). If there is no boot disk, it prompts you to insert it and press the F1 key.
If the floppy disk is not inserted, the computer boots with the IBM Personal Computer Basic, version C1.10, present in ROM.
After installing the new hard disk and the correct operating system, the computer now starts with the IBM PC DOS operating system version 3.30.
There is a system diskette that contains diagnostic software, as well as programs to set the system date and time.
IBM PS/2 model 30, 8530-021 specifications
CPU: Intel 8086, 16-bit, 8 MHz
Coprocessor: optional, Intel 8087, 8MHz
RAM: 640 KB (128 KB soldered to motherboard + 2 x 256 KB 30-pin SIMM with parity)
ROM: 64 KB (contains POST = Power On Self Test, BIOS = Basic Input-Output System, BASIC and graphical character map)
Graphics: Integrated MCGA graphics, 64KB RAM, DB15 output for VGA monitor
Text mode: 80 columns x 25 rows or 40 columns x 25 rows (16 colors)
Graphics mode: 640 x 200 pixels (2 colors) or 320 x 200 pixels (256 colors)
Audio: beep
Keyboard: external PS/2, such as the IBM Model M space saver or enhanced mechanical keyboard
Software supplied: IBM PC DOS version 3.30
Storage media: n. 1 internal floppy disk drive, 3.5", 720 KB (the computer supports up to n. 2 internal floppy disk drives and also a 20MB hard disk)
With regard to the hard disk, the one I installed is 20MB, as required by the specifications of the computer. I also tried to install a 30 MB one, obviously with the same connector, and it works.
Expansion ports, internal:
- N. 3 8-bit ISA expansion slots on riser card
- 34-pin floppy disk drive connector (non-standard, because it also carries power)
- Connector for hard disk 44 poles (the format is proprietary and also carries the power supply)
Expansion ports, external:
- PS/2 keyboard
- Mouse PS/2
- Centronics
- Serial (DB25)
- Monitor (DB15)
Dimensions and weight: 41 x 40 x 10 cm, 8 Kg
Emulation
The IBM PS/2 model 30 computer starts with the IBM PC DOS operating system. It is possible to emulate the MS-DOS environment with DOSBox (although DOSBox is an emulator for x86-based systems).
Power supply
The power supply on the IBM PS/2 model 30 home computer is internal. Behind the computer, there is the IEC C14 power connector, where the mains power cable is connected. My model is powered by 230 V in alternating current 50 Hz and absorbs 70 W.
The voltages generated, in direct current, are:
- 5V, 9A
- 12V, 1.8A
- -5V, 0.1A
- -12V, 0.3A
The front power switch mechanically connects to the switch on the power supply using a metal rod.
Papers
1. IBM PS/2 Model 30 brochure
2. IBM PS2 Model 30 schematics
3. IBM PS/2 Model 30 technical reference
Collection entry date: 27/04/2023