A305/310 and A410/440

Specifications

Processor
ARM (Acorn Risc Machine)
Clock Frequency 4 / 8Mhz

RAM
A305 - 0.5Mb
A310 - 1.0 Mb
A410 - 1.0Mb
A440 - 4.0Mb

Seperate CMOS battery backed RAM : 240 bytes, plus 16 for battery backed real time clock.

ROM
512 Kbytes
Contents:
Machine Operating System (ARTHUR)
(Followed by Risc OS 2 and)
(Later Upgradable to Risc OS 3)
BBC BASIC V
Advanced Disc Filing System (ADFS)
Advanced Net Filing System (ANFS)
Basic Editor
Desk Top Manager
Character Sets: ISO 8859, Latin 1-4, Greek.

Display
European Standard Rate (15.625Khz/50Hz non-interlaced)
18 Screen Modes;
Text----Graphics Res.-----Colours
20x32---160x256----------4,16,256
40x32---320x256--------2,4,16,256
80x32---640x256--------2,4,16,256
132x32--text only----------------16
40x25---text only-----------------2
40x25---Teletext------------------6
80x25---text only------------2,4,16
132x25--text only----------------16

High Scan Rate: for use with monitors such as the NEC Multisync;

3 Screen Modes;
Text----Graphics Res.-----Colours
80x64---640x512--------------2,4,16

Outputs: Analogue RGB + sync; 9-pin D type socket; monochrome composite video; phono socket.

Sound
2 channel Stereo with 7 Stereo positions and 8 voices; 1 internal loud speaker, 3.5mm stereo jack for use with 32ohm stereo headphones or amplifier.

Disc Drives
All machines fitted with one 1 Mbyte (unformatted) 3.5" drive. An additional 3.5" disc or 20 Mbyte hard disc may be added internally. The 300 series also requires a hard disc controller podule and back plane when fitting a hard disc.

Serial Interface
75-19200 baud software selectable; independant Rx/Tx baud rate selectable; 9 pin D-type plug.

Parallel Printer Interface
8 bit Centronics compatible; 25 pin D-type socket.

Keyboard and Mouse
103 key 'enhanced PC' style; two-key roll-over with programmable auot-repeat rate; detachable via 6-pin minature circular connector; Mouse input, 3 button mouse included, via 9-pin minature circular connector; adjustable function key card holder.

Software on Welcome Disc
Welcome Suite - Painting Program, Font Designer, Music Program, tutorials, utilities, 6502 Emulator, Floating Point Emulator, range of Fonts.
Documentation; Welcome Guide, User Guide.

Expansion Port
300 Series;
64 way DIN 41612 connector on main PCB; designed to accept 2 socket optional back plane card.

400 Series;
fitted with back plane card; three 64 way and one 96 way DIN 41612 connectors; provision for co-processor podules e.g. FPU (Floating Point Unit).

Econet
All machines may be upgraded to work with the ECONET Local Area Network by the addition of an internal plug-in module.

Power Input
198 to 264V AC (50Hz)

Dimensions
Computer Unit: width: 362mm; depth: 406mm; height: 97mm (excluding feet)

Keyboard Unit: width: 485mm; depth: 205mm; height: 46mm (excluding feet)

Podules
I/O *
(Input Output Interface to support many existing BBC applications).
Double Width. Provides User Port, 1Mhz Bus and A-D Port, similar to those provided on the Master 128 including the connector types. Previous Master 128 Operating System calls are genreally supported.

ROM *
Single Width. Provides five 32 pin sockets for a range of ROM/EPROM types. The unit can be upgraded to take RAM as an alternative to ROM/EPROM, with an additional two S RAM sockets. This can be battery backed.

MIDI * (Musical Instrument Digital Interface)
This is an upgrade to the I/O podule, contained within the podules double width; The MIDI standard interface is supported. An EPROM upgrade to the I/O podule is provided to enable operating system level control of the MIDI ports.

* (Where Purchased)

Upgrades
RAM
Two kits will be available to upgrade the model 305 0.5 Mbyte RAM to 1.0 Mbyte, and the model 410 1.0 Mbyte RAM to 4.0 Mbytes.

Floppy Disc
A second internal floppy disc drive complete with cable and replacement front panel. *

Hard Disc
An internal 20 Mbyte hard disc as an alternative to a second floppy drive. The upgrade for the 300 Series will also include a hard disc controller podule (single width). *

* (Dealer Fitting Only)

Source of information: Official Acorn Product Brochure.

Related Images

Rear view of an Archimedes A310 with full-width User, Analogue, 1Mhz Bus and Midi Podule.
Also Acorn Hard Disc Podule.

a3xx_2.jpg - 18Kb
Front view of an Archimedes A310. This machine has a hard disc and hence the hard disc activity
light on the front panel. A non hard disc machine has this light omitted.
The design in my opinion is flawed, as to upgrade a non-hard disc machine to hard disc or to add a
second floppy drive involves fitting a new front panel moulding. A better option would have been a
removable panel for the second floppy drive and the hard disc activity light pre-installed.

a3xx_3.jpg - 46Kb
A view inside this machine. The Hard Disc in center front is a SCSI device, popular at the time.

a3xx_4.jpg - 65Kb
This is the Acorn SCSI Hard Disc controller podule.

a3xx_5.jpg - 89Kb
A view of the User, Analogue, 1Mhz Bus, Midi podule. This is an excellent upgrade as it gives the
A310 nearly all the ports required for backward compatability with the BBC Micro range of machines.

a3xx_6.jpg - 35Kb
A view of the Watford Electronics 4-Slot backplane.

a3xx_7.jpg - 27Kb
A view of the front panel. Note the Hard Disc activity light.
Also, note the small square panel to the left of the Archimedes Logo.
I believe this was originally designed for a front mounted power on/off switch.

a3xx_8.jpg - 35Kb
A rear view of the same panel showing possible fixing points for a on/off switch.

a3xx_9.jpg - 69Kb
A view of the A310 mainboard. This machine also has an Econet Module fitted.

a3xx_10.jpg - 70Kb
A closeup view of the mainboard.
Note, the apparent possible upgrades ie vacant positions for Winchester Disc Upgrade.
Did this ever become a production option? I believe the A540 had SCSI as standard.

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