Editing Acorn System 2

{{Infobox computer
| name         = Acorn System 2
| image        = [[File:Acorn System 2.jpg|250px]]
| caption      = Acorn System 2 in a 19-inch card frame
| manufacturer = Acorn Computers Ltd
| type         = Modular microcomputer (Eurocard)
| release date = 1980
| price        = £320 (£480 with PSU); keyboard £136 (1982)
| cpu          = 6502 @ 1 MHz (6809 option)
| memory       = 4 KB RAM + 4 KB BASIC ROM (expandable)
| display      = 40×25 teletext VDU (MC6845 + SAA5050), 8 colours
| storage      = Cassette interface
| os           = Cassette Operating System; Acorn System BASIC
| predecessor  = [[Acorn System 1]]
| successor    = [[Acorn System 3]]
}}

The '''Acorn System 2''' (1980) was the rack-mounted successor to the [[Acorn System 1]]. It put the System 1's Eurocards onto a backplane and added a video card and a BASIC ROM, making the machine straightforward to expand.<ref name="wp">[https://en.wikipedia.org/wiki/Acorn_System "Acorn System"], Wikipedia. Source for the System 2 configuration (8-slot backplane, four cards, external keyboard), the VDU card (MC6845 + SAA5050), the memory card (4K RAM + 4K BASIC ROM, optional +4K RAM and +4K FP ROM), the 6809 CPU option, and the 1982 prices.</ref>

== Configuration ==

The System 2 mounts four Eurocards in a 19-inch sub-rack on an 8-slot backplane, with a separately-supplied external keyboard:<ref name="wp" /><ref name="chris2">Whytehead, Chris. [https://chrisacorns.computinghistory.org.uk/Computers/System2.html "Acorn System 2"], Chris's Acorns / The Centre for Computing History. Source for the typical card set (1 MHz 6502 CPU with 2K Cassette Operating System, 40×25 8-colour VDU, memory card with 4K RAM + 4K BASIC ROM, cassette interface) and the 8-slot card frame.</ref>

{| class="wikitable styled-table" style="width:70%; text-align:center;"
|+'''Acorn System 2 typical cards'''
! Card !! Function
|-
| CPU card || 1 MHz 6502, keyboard interface, 2 KB Cassette Operating System (6809 option)
|-
| VDU card || 40×25 teletext display (MC6845 CRTC + SAA5050 character generator), 8 colours
|-
| Cassette interface card || The System 1 I/O card, with its keypad and LED unused
|-
| Memory card || 4 KB RAM + 4 KB Acorn System BASIC ROM (optional +4 KB RAM and +4 KB floating-point ROM)
|}

The CPU and cassette cards are the same Eurocards as the [[Acorn System 1]]; any of Acorn's standard Eurocards can be added in the remaining slots.<ref name="wp" /> In 1982 the System 2 cost £320 (£480 with power supply), plus £136 for the optional keyboard.

== Maintenance and repair ==

* [[Acorn System 2 Maintenance Guide]]
* [[Acorn System 2 Troubleshooting Guide]]
* [[Acorn System 2 Capacitor Replacement Guide]]

== See also ==

* [[Acorn System 1]] · [[Acorn System 3]] · [[Acorn System 4]] · [[Acorn System 5]]
* [[Acorn System Catalogue]] &mdash; the Eurocard range

== References ==

<references />

{{Navbox-AcornComputers}}

[[Category:Acorn Computers]]