Compukit UK101

From Wikipedia, the free encyclopedia

The Compukit UK101 microcomputer (1979) was a kit clone of the Ohio Scientific Superboard II single-board computer, with a few enhancements for the UK market - notably replacing the 24x24 (add guardband kit to give 32x32) screen display with a more useful 48x16 layout working at UK video frequencies. The video output was black and white with 256 characters generated by a 2 KiB ROM. It had no bit-mapped graphics capability. The video was output through a UHF modulator, designed to connect to a TV set.

It was powered by a 6502 microprocessor CPU running at 1 MHz, and was equipped with up to 8 kibibytes of RAM using 2114 static RAM chips of 1024x4-bit. An additional memory-mapped 1 KiB of RAM was used for the video display. It had the 8K Microsoft BASIC interpreter stored in ROM. In addition to Basic, a 6502 machine code monitor (2Kb) was built into ROM. It allowed programmimg by entering sequences of 6502 operational codes. Later a two pass assembler was available which allowed the use of assembly language.

In common with other home computers of the time, software could be saved and loaded on standard cassette tapes. The UK101 uses the Kansas City standard tape format. I/O was managed by a Motorola 6850 ACIA. This allowed a full RS232 port to be implemented, with the addition of a few extra components and minor modifications to existing jumpers on the board.

The 40 pin expansion socket opened up the world to the UK101. One could attach a dual floppy disk controller (5.5") and a memory expansion card (40K max) to allow faster and reliable save/load of programs/data.

A sound card became available, built around the General Instruments AY-3-8910 , which together with a peripheral interface Adaptor (PIA) chip - 6521, gave the UK101 VOICE.

The UK101 design was published in Practical Electronics, a popular hobbyists magazine at the time.

Kits of parts for building the machine were available from Comp Shop Ltd of Station Road, New Barnet (North London).