Acorn Cambridge Workstation
 | |
| Acorn Cambridge Workstation at The Centre for Computing History (photo: airsynth, CC BY 2.0) | |
| Specifications | |
|---|---|
| Manufacturer | Acorn Computers |
| Type | Scientific workstation |
| Released | 1985 |
| Intro price | £5,845 (1 MB, 1985) |
| CPU | National Semiconductor 32016 with 32081 FPU and 32201 TCU; 6512A I/O processor at 2 MHz |
| Memory | 4 MB (ACW 443); 64 KB for the I/O processor |
| Storage | 20 MB Winchester; 5.25-inch 80-track floppy drive |
| Display | Integral 12-inch Microvitec colour monitor |
| Sound | 4-channel sound generator, internal loudspeaker |
| OS / Firmware | Panos (32016); BBC MOS on the I/O processor |
| Model no. | ACW 100, ACW 121, ACW 143, ACW 443 |
The Acorn Cambridge Workstation (ACW) is a scientific workstation that Acorn Computers sold from 1985. It is the ABC 210 from the cancelled Acorn Business Computer range, relaunched in the same case with a larger hard disc: a National Semiconductor 32016 processor card with 4 MB of RAM running Acorn's Panos operating system, attached through the Tube to a BBC Model B+ derived I/O processor that handles the screen, keyboard, discs and network.[1][2] Acorn User reported it in August 1985 as Acorn's first product since the Olivetti rescue and the only machine of the business range "to see daylight".[3]
Models
[edit | edit source]Acorn's brochure lists four models. Chris Whytehead has only seen the ACW 443 and is not sure the others were built.[4][5]
| Model | Monitor | Floppy drives | Winchester | RAM | Maximum RAM |
|---|---|---|---|---|---|
| ACW 100 | 14-inch mono | none | none | 1 MB | 1 MB |
| ACW 121 | 12-inch mono | 2 x 640 KB | none | 1 MB | 4 MB |
| ACW 143 | 12-inch colour | 640 KB | 20 MB | 1 MB | 4 MB |
| ACW 443 | 12-inch colour | 640 KB | 20 MB | 4 MB | 4 MB |
The prices published differ. Acorn User gave £5,845 for the standard 1 MB machine, £1,000 for each further megabyte and about £8,000 for the full version.[3] Chris Whytehead gives £3,995 including VAT.[5]
Hardware
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The ACW 443 uses the National Semiconductor 32000 chip set: the NS32016 CPU, the NS32081 floating point unit and the NS32201 timing and control unit, with a 32-bit internal architecture and a 16-bit external data bus. A 6512A processor with its own 64 KB acts as the I/O processor and can also run on its own, in which case the machine behaves as a BBC Model B+. Production ACW 443s have 4 MB on the 32016 card, a 20 MB Winchester and an 80-track floppy drive, an integral 12-inch colour monitor and a separate keyboard.[2]
The chassis opens out for service. The upper case lifts off after two rear clips and their metal safety clips are released; each side tray is held by two quarter-turn screws and hinges down, and two more quarter-turn screws release the cradle carrying the monitor, which rises on a pair of scissor stays to expose the I/O processor board in the base. The right-hand tray (seen from the front) carries the 32016 board, and the left-hand tray the Winchester interface boards and the optional mouse adaptor.[2]
| Assembly | Acorn part | Notes |
|---|---|---|
| ABM control board (I/O processor) | 0133,400 on bare PCB 0233,000 | 6512A CPU (IC42) at 2 MHz, 64 KB of 4864 DRAM, WD1770 floppy controller (IC16), 6845 CRTC (IC78), video processor ULA (IC53), 16 MHz crystal X1 |
| Large 32016 PCB | 0118,100 on bare PCB 0218,100 | 32016 CPU, 32081 FPU, 32201 TCU, Tube ULA, 128 x 4256 (256K x 1) DRAM, Pandora high and low ROMs, 20 MHz crystal |
| Winchester host adaptor | 0127,000 on bare PCB 0227,000 | SCSI to 1 MHz bus interface |
| Adaptec PCB | 0837,000 | Adaptec ACB-4000/A ST-412 to SCSI controller |
| Power distribution PCB | 0120,005 | Plugs PL1 to PL10 and one 10 ohm 1 W resistor (R1) |
| Power supply | 0831,104 | 85 W switch-mode unit, field replacement only |
| Monitor kit | 0836,100 | 12-inch colour, Microvitec |
| Floppy drive / Winchester | 0831,500 / 0831,400 | Field replacement only |
Sources: Acorn's parts lists and chapter texts in the service manual.[2]
The I/O processor board is the BBC Model B+ board without a few parts, the most obvious being the UHF modulator. It has 64 KB with shadow screen memory, 12 KB of paged RAM, room for five 32 KB sideways ROMs, the Teletext mode 7 display, RS423, cassette, the analogue port, Econet and a Centronics printer port.[2] Its ROM set is the ACW OS ROM (IC71), DNFS (IC35), ADFS (IC62), the terminal emulator (IC57), ACW DFS (IC44) and BASIC (IC68).[2] See BBC Micro Model B+ for the board family.
The 32016 card carries the Pandora kernel in two ROMs; Panos uses it to reach the filing systems on the I/O processor. Its configuration links S1 and S2 tell the software that no FPU or no MMU is fitted. Acorn listed the memory manager as "not yet available".[2] Acorn User reported in 1985 that Logica's Xenix port was not supported because the memory management unit was not ready, and that a socket for it was left on the board.[3]
The clock speed is reported differently. Acorn's brochure and Acorn User give 8 MHz.[4][3] Chris Whytehead records 6 MHz for the 32016 in his ACW.[5] Acorn's parts list for the 4 MB board specifies a 20 MHz crystal and 10 MHz-rated CPU, FPU and TCU, and the service manual says the TCU's clocks run at half the crystal frequency.[2]
Discs
[edit | edit source]The Winchester is a half-height 20 MB drive to the left of the floppy drive, run through an Adaptec ACB-4000 ST-412 controller and Acorn's host adapter on the 1 MHz bus. Acorn's specification gives 612 cylinders, four heads, 33 sectors of 256 bytes and 3,600 rpm; the formatting appendix gives the parameters for an NEC 5126 drive as four heads, 615 cylinders, step rate code 2, reduced write current cylinder 128 and landing zone 49.[2] The floppy drive takes 5.25-inch double-sided 80-track discs: 640 KB under ADFS and 400 KB per disc under DFS, according to the formatting appendix, while the hardware overview calls it a 700 KB drive.[2]
The heads must be parked before the machine is switched off or moved. From Panos type Logoff ADFS: then .Quit; from the Pandora or BASIC prompt type *ADFS then *BYE.[2]
Power and monitor
[edit | edit source]The 85 W switch-mode supply is screwed to the VDU cradle with heat-conducting compound between them and feeds the boards through Faston connectors. Acorn gives +5 V as 4.9 to 5.2 V and +12 V as 11.4 to 12.6 V.[2] The monitor is a medium-resolution Microvitec unit with an EHT of about 24 kV; Acorn warns that its high voltages can remain for several hours after the mains is disconnected.[2]
Ports
[edit | edit source]
The rear panel has composite video on a BNC socket, RGB on a 6-pin DIN socket, RS423 on a 5-pin domino DIN (75 to 9,600 baud), cassette, a 15-way analogue input, Econet on a 5-pin DIN, the 25-way keyboard socket, a 24-way IDC Centronics printer connector, a 37-way 1 MHz bus connector and, with the optional mouse adaptor fitted, a 9-way mouse socket. Acorn warns that an Econet plug fits the cassette socket; it does no harm to either, but it stops the whole network until it is moved.[2] The keyboard has a reset button and a Tube on/off rocker switch, with an LED showing whether the 32016 is in use.[2][5]
Software
[edit | edit source]The ACW runs Panos on the 32016 and the BBC MOS on the I/O processor. Acorn's brochure lists Fortran 77, ISO Pascal, C and Cambridge LISP as bundled languages, with BBC BASIC and the 32000 assembler; terminal emulation for VT52, VT100 and Tektronix 4010 is in ROM.[4] With the Tube switched off the machine starts as a BBC B+ with the banner "Cambridge Workstation" and ADFS or, with CTRL and D held, ACW DFS.[2]
Chris Whytehead's ACW
[edit | edit source]Chris Whytehead's ACW 443, number 48, came from an ex-Cambridge University student in 1992 with Panos on the disc and the languages in their boxes, and works.[5]
| Item | Fitted |
|---|---|
| I/O processor board | 233,00 issue 1, Rockwell R6512AP at 2 MHz, 64 KB, 48 KB ROM fitted (192 KB maximum) |
| Disc controller | WD1770PH; ADFS and DFS |
| Hard disc | Acorn Winchester Disc Host Adaptor (227,000 issue 2) with an Adaptec ACB400 board (as recorded); 20 MB |
| Second processor | Board 218,100 issue 1, Large 32016, 6 MHz, 4 MB |
| Operating systems | OS 2.00 on the I/O processor; Panos 1.4 |
Maintenance and repair
[edit | edit source]Acorn's service manual covers disassembly, the monitor, component-level fault finding on the I/O board and the 32016 board, the Winchester system and the parts lists. The repair guides draw on it:
- Acorn Cambridge Workstation Maintenance Guide: opening the case, the power supply, fans, discs, head parking and the monitor.
- Acorn Cambridge Workstation Troubleshooting Guide: Acorn's start-up symptoms, rail and current checks, the 32016 checks and memory test, and Winchester faults.
- Acorn Cambridge Workstation Capacitor Guide: the polarised capacitors from Acorn's parts lists.
Warning: the monitor holds high voltages for hours after the mains is removed. Discharge it before working near the cradle; see CRT Discharge Procedure.
Documentation
[edit | edit source]- Acorn Cambridge Workstation Documentation: the ACW 443 Service Manual (0420,001, issue 1, January 1987) and Acorn's Cambridge Workstation brochure.
- Acorn Business Computer Documentation: the ABC range brochure.
- Acorn 32016 Second Processor Documentation: the 32016 second processor for the BBC Micro.
Gallery
[edit | edit source]-
An ACW showing the Panos 1.42 start-up line (photo: Tiziano Garuti, CC0) -
Rear panel -
4 MB 32016 processor board
Related pages
[edit | edit source]- Acorn ABC210, the 1984 design the ACW was built from
- Acorn ABC200, Acorn ABC300 and Acorn ABC310
- Acorn 32016 Second Processor
- BBC Micro Model B+
References
[edit | edit source]- ↑ Whytehead, Chris. "Acorn Business Computer", Chris's Acorns, The Centre for Computing History (retrieved 2026-10-02). The ABC 210 was the only model of the range to reach public sale, relaunched as the Acorn Cambridge Workstation; most other ABC models are said to have been rebuilt as ACWs; the ACW is the ABC 210 with a 20 MB disc.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 Acorn Computers, ACW 443 Service Manual, reference 0420,001, issue 1, 7 January 1987. Hosted on this wiki: File:Acorn ACW 443 Service Manual.pdf; described on Acorn Cambridge Workstation Documentation. Printed page numbers are cited.
- ↑ 3.0 3.1 3.2 3.3 "Workstation puts power on desks", Acorn User, August 1985, pp. 7 and 11. Scan via Chris's Acorns. First product since the Olivetti rescue; 32016 at 8 MHz with 4 MB, Winchester, floppy, bundled Fortran 77, C, ISO Pascal and Lisp, BBC BASIC and assembler; the full version about £8,000; standard 1 MB version £5,845, upgrades £1,000 per MB; Xenix not supported because the memory management unit was not ready, socket left on the board; Econet built in.
- ↑ 4.0 4.1 4.2 Acorn Computers Limited, Scientific Division, brochure Acorn Cambridge Workstation, undated, product range page (PDF page 9). Hosted on this wiki: File:Acorn Cambridge Workstation brochure.pdf.
- ↑ 5.0 5.1 5.2 5.3 5.4 Whytehead, Chris. "Acorn Cambridge Workstation", Chris's Acorns (retrieved 2026-10-02). Four models listed, only the ACW 443 seen; priced at £3,995 including VAT; ACW number 48 with its specification and software; photographs.