Glossary of Terms


6845 CRT

A Cathode Ray Tube Controller IC from Motorola, designed to generate the signals necessary to interface with a raster display. Used in the Amstrad CPC, Acorn BBC, and IBM PC MDA and CGA cards. See also the related MOS Technology 6545.


(see Intel 8255)


(see AY-3-8912)


Ad Lib

The Ad Lib used Yamahas YM3812 sound chip which produces sound via FM synthesis. Digital audio (PCM) was not supported, a key feature supported by later competition (such as the Creative Labs Sound Blaster).

AMSDOS (Amstrad Disk Operating System)

AMSDOS is a disk operating system for the 8-bit Amstrad CPC Computer (and various clones). It first appeared in 1984 on the CPC464, with added 3-inch disk drive, and then on the CPC664 and CPC 6128. AMSDOS was provided built-in to ROM (either supplied with the external disk drive or in the machine ROM, depending on model) and was accessible through the built-in Locomotive BASIC as well as through firmware routines. Its main function was to map the cassette access routines (which were built-in to every CPC model) through to a disk drive. This enabled the majority of cassette-based programs to work with a disk drive with no modification. AMSDOS was able to support up to two connected disk drives.AMSDOS (Amstrad Disk Operating System)


The codename of the Amstrad CPC range of computers during development. Arnold = CPC464, Arnold 2 = CPC664, Arnold 3 = CPC6128, Arnold 4 = Cost-reduced CPC464 and CPC6128, Arnold 5 = CPC464+ and CPC6128+


The PC/AT (Advanced Technology) was IBM's second generation of Personal Computer (PC), launched in 1984 with the brand new Intel 80286 CPU running at 6 MHz.


A 3-voice Programmable Sound Generator chip developed by General Instrument in the early 1980s. It was used in the Intellivision and Vectrex video game consoles and the MSX, Atari ST, Amstrad CPC, Oric 1, Colour Genie, Elektor TV Games Computer and Sinclair ZX Spectrum 128/+2/+3 home computers as well as the Mockingboard sound card for the Apple II family.



CGA (Colour Graphics Adapter)

IBMs first colour graphics card, and the first colour computer display standard for the IBM PC. A CGA card featured several graphics and text modes. The highest resolution of any mode was 640×200, and the highest colour depth supported was 4-bit (16 colours) with the most commonly used combination of 320x200 with 4 colours.


A parallel data interface named after the U.S. company that developed it. The Centronics parallel port began life as a 36-pin ribbon cable connector, but was later changed to the more common 25-pin connector when IBM used them on their PC range, resulting in the now familiar parallel cable with a DB25M at one end and a 36-pin micro ribbon connector at the other.

CP/M (Control Program for Microcomputers)

An operating system originally created for Intel 8080/85-based microcomputers by Gary Kildall of Digital Research, Inc. Initially confined to single tasking on 8-bit processors and no more than 64K of memory, later versions of CP/M added multi-user variations, and were migrated to 16-bit processors. CP/M would also run on systems based on the Zilog Z80 processor since the