The Miles Gordon Technology reference article from the English Wikipedia on 24-Apr-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Miles Gordon Technology

Cofounded by Alan Miles and Bruce Gordon, MGT was a small company, initially specialising in high-quality add-ons for the Sinclair ZX Spectrum home computer.

As the Spectrum became hugely popular, the lack of a mass-storage system became a problem, and Sinclair's response, the Interface 1 and Microdrive storage system, was, typically, very cheap and technologically innovative but also rather limited. Also used in the Sinclair QL, microdrives used tiny postage-stamp sized storage cartridges containing an endless tape loop. Each cartridge held around 85K, but they were slow, unreliable and the media were relatively expensive.

Many companies developed proprietary interfaces to connect industry-standard floppy disk drives to the Spectrum - one of the most successful being the Opus Discovery. However, these were all to some degree incompatible with Sinclair's system.

MGT's approach was different. It produced two different floppy-disk interfaces for the Spectrum, first the DISCiPLE and later the cut-down PlusD. Both, however, shared certain features:

• a Shugart-compatible port for connecting one or two floppy diskette drives (the de facto standard created by Shugart Associates)
• a parallel printer port
• a "magic button".

The latter generated a non-maskable interrupt, freezing any software running on the Spectrum and allowing it to be saved to disk. This made it simple to store tape-based games on disk, to take screenshots and to enter cheat codes. A duplicate expansion connector at the back allowed other peripherals to be daisy-chained, although the complexity of the DISCiPLE meant that many would not work correctly.

However, the real innovation was in the ROM. Unlike most of the competing systems, this was compatible with the Sinclair's extended ROM, meaning that the same BASIC commands used to operate Microdrives or the ZX Printer now could control floppy disk drives or a standard parallel printer. As well as being BASIC-compatible, though, it also mimicked the machine code entry points in the Interface 1 - the so-called "hook codes". This meant that any Microdrive-specific software could use floppy disk drives connected to MGT interfaces instead, without modification.

Sinclair's Microdrive command syntax was so complex that a selling point of many disk interfaces was that their commands were simpler. While loading from tape required a simple

LOAD "progname"

the equivalent Microdrive syntax was

LOAD *"m";1;"progname"

Given the complexity of entering punctuation on the Spectrum's tiny keyboard, this was cumbersome. In addition to supporting the Sinclair syntax, MGT's code reduced the command to

LOAD d1;"progname"

Later, MGT produced the Lifetime Drive, an external floppy drive designed to be compatible with all the leading makes of microcomputer available at the time.

The final product, which resulted in the company's failure, was the SAM Coupe.

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