The Acorn System 3 was the second in a series of 'proper' computers with screen & keyboard, they comprised Eurocard sized boards housed in 19" Vero Card Frame. The System 3 added Floppy Disk storage, it came in two versions: a bare bones System 3 and full spec System 3A.
Both systems comprised the same basic set of 4 Eurocards: a 6502 CPU Board, 40x25 VDU (Teletext) Interface Board, 8K RAM + 8K ROM Board and a Floppy Disk Controller Board all in a 3U Vero Card Frame. The basic System 3 was aimed at the DIYer and came as a kit (£710) or assembled and tested (£774), the System 3A was more complete with fully populated cards an enclosed card frame and front panels but was only available assembled and tested (£1075). An ASCII keyboard (£96) and monitor were required but not included.
"The System 3 in its basic form is a system driving a
single disk. The hardware consists of a card frame, backplane with 4 sockets,
6502 CPU, VDU interface, 8K RAM, floppy disk module, DOS and resident 4K BASIC.
The mini-floppy disk drive is mounted in a 5¼"
module together with its controller card and provides approximately 100K bytes
of storage. A DOS ROM on the CPU card controls the drive and handles files and
input/output devices i.e. the parallel ASCII keyboard and memory mapped VDU.
Supplied with each system is a utilities disk with a formatting program for soft
sectored disks. Acorn software e.g. BASIC, LISP, an Assembler and other
compilers and interpreters may be loaded from disk or contained in ROM.
All the Acorn Eurocards are compatible with this
configuration, allowing enormous variations on a modular basis. The illustration
above shows the addition of a further 3 RAM cards (giving 32K bytes of memory in
total) and a Versatile Interface Board all contained in a stylish casing.