Acorn ABC300
The Acorn ABC 300 is the twin floppy disc 80286 model of the Acorn Business Computer (ABC) range: an IBM PC compatible business machine with an Intel 80286 second processor attached through the Tube to the range's BBC Model B+ derived I/O board, running Digital Research's Concurrent operating system with a graphical desktop manager.[1][2] It is the ABC 310 without the hard disc and colour screen.[3] Acorn cancelled the ABC range in 1985 and the ABC 300 was not sold; Chris Whytehead lists it as wanted.[1]
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| Acorn's brochure photograph of the ABC range; all models share this case and keyboard | |
| Specifications | |
|---|---|
| Manufacturer | Acorn Computers |
| Type | Business computer (announced 1984, not released) |
| Intro price | £2,599 + VAT (announced 1985) |
| CPU | Intel 80286 second processor; 6502-family I/O processor |
| Memory | 256 KB standard, up to 1 MB (Acorn User, 1984) |
| Storage | Two 5.25-inch 720 KB floppy drives |
| Display | Built-in monochrome (green) monitor |
| Sound | — |
| OS / Firmware | Digital Research Concurrent DOS with a desktop manager (GEM) |
| Model no. | ABC 300 |
Specification as announced
edit| Item | Details | Source |
|---|---|---|
| Processor | Intel 80286 second processor; 6502 for input and output | Brochure; Acorn User Nov 1984 |
| Memory | 256 KB standard, upgradable to 1 MB | Acorn User Oct 1984 |
| Discs | Two 720 KB 5.25-inch floppy drives | Brochure; Acorn User Nov 1984 |
| Screen | Green (monochrome) | Acorn User Oct and Nov 1984 |
| Software | Concurrent operating system and Desk Top Manager; CP/M, MS-DOS and PC-DOS applications | Brochure; Acorn User Nov 1984 |
| Price | £2,599 plus VAT | Acorn User Mar 1985 |
Sources: the brochure,[2] Acorn User's report of October 1984,[4] its November 1984 range table[5] and its March 1985 price list.[6] Wikipedia gives the ABC 300 1,024 KB;[7] Personal Computer World's review machine, a 310, had 1 MB fitted while its specification box gave 512 KB.[3]
History
editThe ABC range was first shown in public at the 1984 PCW Show, where the 80286 machines ran an icon-driven desktop manager.[5] Acorn's sales director told Acorn User that the company was aiming at vertical markets such as research and communications, not at IBM directly.[5] In April 1985 Acorn User reported that Acorn's London office still planned to have the Personal Assistant and the 300 series on display at the end of March, but that Acorn could not name a dealer stocking the machines, that production of the ABCs was reported to have stopped, and that Olivetti was expected to hold the range back.[8] The range was cancelled; only the 32016 ABC 210 reached sale, as the Acorn Cambridge Workstation.[1]
Hardware
editApart from the drives and screen, the ABC 300 is described in the same terms as the ABC 310 reviewed by Personal Computer World: a minimal 80286 co-processor board carrying the processor, TTL, RAM, 32 KB of ROM and a Ferranti Tube ULA, and a BBC-derived I/O board redesigned with eight sideways ROM sockets and support for double-density discs.[3] The details of that review are on Acorn ABC310. The keyboard has a reset button and a rocker switch that turns the 80286 off, leaving a BBC B+.[3][1]
Construction and service
editThe ABC 300 uses the common ABC case, described on Acorn ABC110#Construction. No Acorn service manual for the 80286 models is known. The case, power supply wiring, Microvitec monitor and I/O processor board of the 32016 production machine are covered by Acorn's ACW 443 Service Manual; see Acorn Cambridge Workstation Documentation and the Acorn Cambridge Workstation Maintenance Guide.[9]
Warning: the monitor electronics are uncased and some hold a high voltage for some time after switch-off.[3] See CRT Discharge Procedure.
Related pages
editReferences
edit- ↑ 1.0 1.1 1.2 1.3 Whytehead, Chris. "Acorn Business Computer", Chris's Acorns, The Centre for Computing History (retrieved 2026-10-02). ABC 300: twin 5.25-inch floppy drives, Intel 80286 second processor (never offered for the BBC Micro; the BBC Master 512 used an 80186), Digital Research Concurrent DOS with a desktop manager; listed as wanted. With the Tube off, the ABC machines work as BBC B+ computers.
- ↑ 2.0 2.1 Acorn Computers, brochure "The Acorn Business Computer", APP01. Hosted on this wiki: File:Acorn Business Computer brochure (APP01).pdf. Page 3: the ABC 300 is based on the 80286 running the Digital Research Concurrent operating system with a Desk Top Manager, running CP/M, PC DOS, MS DOS or Concurrent applications. Page 4: 80286 main processor, twin 720 KB drives, Concurrent operating system, Desk Top Manager.
- ↑ 3.0 3.1 3.2 3.3 3.4 Bright, Peter. "Acorn ABC 310", Personal Computer World, vol. 8 no. 4, April 1985, pp. 120-126. Scan via Chris's Acorns. The main difference between the 300 and the 310 is that the 300 has two floppy drives and the 310 a hard disc; both ship with Concurrent DOS 286 and GEM.
- ↑ "New Acorn micro", Acorn User, October 1984, pp. 7 and 9. Scan via Chris's Acorns. The 80286 "executive workstations": the 300 with two 700 KB drives and a monochrome monitor, the 310 with one drive, a Winchester and a colour screen; 256 KB standard, upgradable to 1 MB; a mouse to follow for the 300 machines.
- ↑ 5.0 5.1 5.2 Quinn, Tony and van Someren, Alex. "Vertical tack of the ABC", Acorn User, November 1984, pp. 30-31. Scan via Chris's Acorns. The 300 series uses the Intel 80286 and is compatible with the IBM PC, with Concurrent OS and Desktop Manager; Table 1 gives the ABC 300 as 80286, 2 x 720 KB, no hard disc, green screen, CP/M, MS-DOS and PC-DOS.
- ↑ "ABC goes for special sectors", Acorn User, March 1985, p. 7. Scan on archive.org. ABC 300 £2,599 and ABC 310 £3,999, plus VAT.
- ↑ "Acorn Business Computer", Wikipedia (retrieved 2026-10-02). ABC 300 listed with 1,024 KB, twin 720 KB drives, Concurrent DOS 286 and a monochrome monitor.
- ↑ Acorn User, April 1985: "Beeb safe, but ABCs under review", p. 7, and "Business computers miss release dates", p. 129. Scan on archive.org.
- ↑ Acorn Computers, ACW 443 Service Manual, reference 0420,001, issue 1, January 1987. Hosted on this wiki: File:Acorn ACW 443 Service Manual.pdf.