Acorn R140

The Acorn R140 is Acorn Computers' first Unix workstation, sold from early 1989. It runs RISC iX, Acorn's port of Berkeley 4.3 Unix with System V extensions and the X Window System, on the hardware of the Archimedes 440/1: an ARM2, 4 MB of RAM, a 60 MB ST506 hard disc and a 3.5-inch floppy drive. RISC OS 2 in ROM starts the machine and then loads RISC iX from the hard disc.

Acorn R140

An R140 running RISC OS, with its PC-style keyboard (photo: Chris Whytehead, CC BY-SA 3.0)
Specifications
Manufacturer	Acorn Computers
Type	Unix workstation
Released	1989
Intro price	£3,949 ex VAT with Ethernet; £3,500 ex VAT without (June 1989)
CPU	ARM2 (4/8 MHz)
Memory	4 MB (32 KB MEMC pages)
Storage	60 MB (unformatted) ST506 hard disc; 3.5-inch floppy drive, 800 KB formatted
Display	Up to 1152 × 900 monochrome; 640 × 480 in 16 colours from 4096
Sound	—
ROM	512 KB (RISC OS 2)
Power	198 to 264 V AC, 70 VA
OS / Firmware	RISC iX (4.3BSD Unix), booted from RISC OS 2
Successor	Acorn R260
Model no.	UNX01 (base system); UNX01/AKA25 (with Ethernet)

The R140 uses the main board, case and power supply of the Archimedes 400/1 series (the first R140s were built on a slightly adapted A440), and Acorn serviced both from one manual. The board-level procedures are in the Acorn Archimedes 400/1 Series Maintenance Guide, Acorn Archimedes 400/1 Series Troubleshooting Guide and Acorn Archimedes 400/1 Series Capacitor Guide; the sections below cover what is particular to the R140.

History

Acorn's January 1989 leaflet describes the R140 as "the first in a series of personal workstations running the UNIX operating system". By June 1989 Acorn listed the workstation with Ethernet (UNX01/AKA25) at £3,949 ex VAT and the base system without the Ethernet card (UNX01) at £3,500, with twelve months' on-site maintenance included. Chris Whytehead compares this with £2,299 ex VAT for the A440 at its launch, and records that the first R140s were built on a slightly adapted A440 and later ones on the A440/1.

Wikipedia records a 1990 offer bundling the R140 with Ethernet and a monitor at £2,999 ex VAT, an upgrade to RISC iX 1.2 for R140 owners from £349, and the ARM3-based Acorn R260 and Acorn R225 that followed in 1990. The Acorn A680 was the earlier, unreleased RISC iX development machine.

Specification

R140 specification (Acorn leaflets APP214 and APP221, service manual)

Item	Specification
Processor	ARM 32-bit RISC processor; the service manual gives 4/8 MHz and typically 4 MIPS for the 400/1 and R140
Memory	4 MB RAM, 32 KB pages; 512 KB ROM
Storage	60 MB (unformatted) ST506 hard disc; 1 MB (unformatted) 3.5-inch floppy drive; a second external Winchester can use the internal ST506 controller
Expansion	Four expansion card slots (three free on the Ethernet model); internal Econet module that does not use a slot
Keyboard and mouse	103-key "enhanced PC" style keyboard; three-button mouse
Interfaces	Serial, parallel; Ethernet and thin Ethernet (Cheapernet) on the AKA25 card
Display	1152 × 900 monochrome (144 × 45 or 96 × 32 characters); 640 × 480 colour, grey-scale or monochrome with 16 colours from 4096
Software	RISC iX (4.3BSD with SVID extensions, two-user licence), ANSI C compiler, X11 release 2 with awm, twm and uwm, X.desktop, NFS 3.2 and Yellow Pages, RISC OS, and MS-DOS through the PC Emulator

Sources: leaflets APP214 and APP221; processor figures from the service manual's technical specification.

R140 options (APP221, June 1989; prices ex VAT)

Code	Option	Price
AKA20	Floating point expansion card with a WE32206 co-processor	£599
AKA25	Ethernet expansion card, thick and thin (Cheapernet) Ethernet	£449
AKA30	SCSI adapter card, up to seven devices	£299
AKA42	PC Emulator	£99
ADF10	Econet module	£49

Hardware

An R140 with the top cover removed. This machine has been upgraded with an ARM3, an IDE card and an Atomwide Ethernet card (photo: Chris Whytehead, CC BY-SA 3.0)

The main board is the Acorn Universal Board used in the 400/1 series. Chris Whytehead's R140 carries board 283,000 issue 2 on the four-slot backplane 0283,040, the same backplane as the A410, A440 and A680. Acorn's service manual gives the R140's memory as 4 MB with a 32 KB page size, the same as the A440/1, and its functional test disc reports an R140 as an A440/1.

The differences from an A440/1 are in what Acorn fitted and supplied: the 60 MB hard disc, the 103-key PC-style keyboard, the three-button mouse, the Ethernet card on the UNX01/AKA25 model and the RISC iX software. Wikipedia notes that an A440/1 with 4 MB and a suitable hard disc can also run RISC iX.

Rear panel

Acorn's operations guide lists these connections on the back of the system unit:

• Mono and Sync sockets for a high-resolution monochrome monitor; with a low-resolution monitor the Mono socket carries the whole signal.
• Analogue RGB socket, not suitable for TTL RGB monitors.
• Serial port and parallel printer port.
• Headphone socket for a 3.5 mm stereo jack, mainly for RISC OS.
• An Econet socket, blanked off if the Econet module is not fitted.
• Four expansion card positions behind the blanking panel, for four single or two double cards, and the Ethernet card where fitted.
• Mains input, mains output for a monitor, and the rocker on/off switch.

The 400/1 manual rates the unswitched mains outlet at 3 A continuous and the inlet at 70 VA.

RISC iX

RISC OS 2 starts first. RISC iX can then be booted from the RISC OS desktop or set to start automatically; halt -RISCOS, typed as root, closes RISC iX down and returns to the RISC OS command line or desktop. Close RISC iX down properly before switching off. To stop the machine from RISC OS, use *Shutdown, which also parks the hard disc heads.

Acorn recommended a level zero dump backup of the filesystem as soon as the system was installed. RISC iX was supplied pre-installed or installed on site from tape by Granada Microcare, and the core system could be backed up to three floppy discs. Chris Whytehead restored a minimal RISC iX to his R140 from the three recovery floppies (one ADFS, two in the Unix UFS format), but a full installation also needs a tar archive of RISC iX 1.15 on media the machine can read.

Warning: Acorn's dealer test disc includes a hard disc formatter, verifier and soak test. Running these tests destroys the data on the disc, which on an R140 means the RISC iX installation. Back up the disc before running them.

Maintenance

The general procedures for the board, power supply, drives and expansion cards are in the Acorn Archimedes 400/1 Series Maintenance Guide. Acorn's operations guide adds these R140 user tasks.

Backup batteries

Two AA (LR6) alkaline cells in a battery nest power the clock and the configuration memory. Acorn's guide says to change them once a year. Old cells leak and corrode the holder and board; see Battery Explosion, Capacitor or Corrosion Damage and the battery section of the 400/1 maintenance guide.

1. Log in as root, close RISC iX down with halt -RISCOS, type *STATUS and write down the configuration, which will be lost.
2. Type *Shutdown to park the hard disc, then switch off and unplug.
3. Remove the three screws at the top of the back panel and the screws on each side, then slide the top cover back far enough to expose the front half of the machine.
4. The battery nest is at the front right-hand corner as seen from the back. Leave its flying lead to the main board connected. Fit the new cells the right way round; the nest will accept them reversed.
5. Refit the cover, hold down R while switching on to reset the configuration to factory settings, then use *STATUS and *CONFIGURE to restore the settings you noted. Reset the date and time.

Fan filter

The cooling fan has a filter beside the battery nest, held by a clamp and two M4 nuts. Acorn's guide says to change it about once a year; the replacement filter is Acorn part 0276,034. Make sure the nuts go back in the right positions and are tight.

Cleaning

Clean the case with a soft, slightly damp cloth. To clean the mouse, remove the ball retainer screw, clean the three rollers with a swab moistened with tape head cleaner, and wipe the ball with a dry, lint-free cloth.

The moulded mains plug takes a 5 A fuse.

Fault finding

Hardware faults are diagnosed as for the 400/1 series, using the Acorn Archimedes 400/1 Series Troubleshooting Guide and the hosted service manual. The operations guide covers what a user sees first:

R140 start-up problems (operations guide pp. 83 to 87)

Symptom	Probable cause	Action
Nothing happens at power on, no power or hard disc light	Mains supply or plug fuse; cables	Check the outlet and the 5 A plug fuse; reconnect each cable
Power and keyboard lights on, nothing on the screen	Monitor cable, adjustment or monitor; for a low-resolution text-only monitor, the internal links may not have been set	Check the cables and brightness; check the monitor type and the links
Fuzzy or jumpy picture	Monitor type configured wrongly; alignment; loose signal cable	Check the configured monitor type, then the monitor's own adjustments
Powers on, then nothing happens	Monitor, or corrupted CMOS RAM settings	Check that the H/DISC light flashes intermittently; see the RISC iX System Administrator's Manual for the CMOS settings
RISC iX starts to boot but stops before the login: prompt	A one-off error, or a corrupted filesystem if it happens again	Restart; if it persists, Acorn says the filesystem is likely to be corrupted
Shuts down without warning	Remote shutdown, a failed power supply or a blown plug fuse	Restart; if it will not start again, check the fuse and the supply

Documentation

• Acorn R140 Documentation: the R140 Operations Guide (0483,710) and Acorn's APP214 and APP221 leaflets.
• Acorn A400-1 and R140 Service Manual: part 0483,075, issue 1, July 1989, the dealer service manual for the 400/1 series and the R140.
• Personal Computer World reviewed the R140 in March 1989; Chris's Acorns has the scan.

Gallery

• 
  Main board: the Acorn Universal Board 283,000 issue 2, as in the 400/1 series

Related pages

• Acorn Archimedes A440, whose 400/1 version the R140 is built on
• Acorn Archimedes 400/1 Series Maintenance Guide
• Acorn Archimedes 400/1 Series Troubleshooting Guide
• Acorn Archimedes 400/1 Series Capacitor Guide
• Acorn R260 and Acorn R225, the ARM3 RISC iX workstations
• Acorn A680