Compukit UK101

  • 6502 CPU 1MHz
  • 8k bytes of memory
  • 1k bytes of Memory mapped Video Ram
  • BASIC interpreter in 8k of ROM
  • Monitor (OS) in 2k of ROM

The Compukit UK101 microcomputer (1979) was a kit clone of the Ohio Scientific Superboard single-board computer, with a few enhancements for the UK market - notably replacing the 24x30 screen display with a more useful 48x16 layout working at UK video frequencies.

Practical Electronics published four articles describing the machine. These articles were written by Dr A.A.Berk and appeared in the August, September, October and November 1979 issues of the magazine.


BBC Model B+

  • 6502A CPU 2MHz
  • 64kB Ram
  • 32kB Rom

Acorn introduced the Model B+ in mid 1985, the Model B+ was little different to its predecessors, adding only more memory (now 64k) and having a higher price :-) The extra RAM in the Model B+ BBC Micro was assigned as two blocks, a block of 20 kB dedicated solely for screen display (so-called "Shadow" RAM) and a block of 12 kB of 'special' Sideways RAM

Large numbers of games were written for the Beeb, including the original version of the classic Elite. A range of hardware add-ons and expansions was available, and the machine had provisions for floppy disk drives and networking hardware. There were also sockets for the addition of extra ROM chips. The built-in ROM had aresident BBC BASIC programming language interpreter on it.


Commodore 64SX

  • 6510 CPU 1MHz
  • 64kB Ram
  • 20kB Rom
    • 9 KB BASIC 2.0;
    • 7 KB KERNAL;
    • 4 KB character generator

The C64 used an 8-bit MOS Technology 6510 microprocessor (a close derivative of the 6502 with an added 6-bit internal I/O port that in the C64 is used for two purposes: to bank-switch the machine's ROM in and out of the processor's address space, and to operate the datasette tape recorder) and had 64 kilobytes of RAM, of which 38 kB were available to built-in Commodore BASIC 2.0.

In 1984 Commodore released the SX-64, a portable version of the C64. The SX-64 has the distinction of being the first full-color portable computer. The base unit featured a 5 inch (127 mm) CRT and an integral 1541 floppy disk drive.


Atari 520ST

  • Motorola 68000 CPU 8MHz
  • 512kB Ram
  • Atari TOS/GEM

The Atari 520ST was introduced at the Winter CES in January of 1985, 6 months before the Commodore Amiga. Atari did take some shortcuts, though, as the Operating System did not yet exist in ROM, and had to be loaded from floppy-disk when powered on (but then again, so did the Amiga). The 520ST also had no internal floppy drive, but later versions included it.

The 520ST are based on the Motorola 68000 CPU, which has a 16-bit external bus, and 32-bit internal, thus the 520'ST' means 'sixteen / thirty two'. The Operating System is 'TOS', or 'Tramiel Operating System'.