Way back in 1979, Cambridge company Tangerine had a successful run of producing one of the world's first microcomputer kits based around the then pretty new MOS 6502 CPU. Designed by Dr Paul Johnstone, The Microtan65 sold as either a standalone kit with a hex keypad for data entry to its 1K monitor, or as a bigger system in a pleasing 3U rackmount-style case with a multi-slot backplane and decent metal-cased separate ASCII keyboard, allowing BASIC to be run amongst a plethora of other things including floppy drives.

By 1982 Paul Lancaster was designing a followup machine which internally was called the Tigress, or Microtan 2. Instead of the 6502 of the Microtan, the Tigress was run by 3 separate CPUs. The main processing was via a Z80 so the machine could run CP/M with its 64K RAM, then there was a Motorola 6809 for IO (which included GPIB) and an NEC D7220 graphics processor that had its OWN 96K RAM to power the high resolution graphics screen of 512x512 pixels. Costs to produce the machine were too much however, and Tangerine had been pushed down the home micro route after their financial consultant, John Tullis, came up with the idea of producing one. Thus the design of the Tigress was sold to another local company, HH Electronics in Bar Hill. HH who were better known for their audio amplifiers, had the manufacturing capability to make the Tiger in house and by 1983 prototypes were produced.

The base machine is an attractive design with its separate keypad and multicolour function keys that doubled as colour selection keys for Prestel mode. Inside you can see the 3 parts that make up the whole machine - Z80 + ROM + RAM at the bottom of the motherboard, 6809 with its ROM and RAM to the right and at the top were the 3 monstrous 32K RAM boards that made up the video RAM for the D7220 graphics chip. Also present on a separate tray was the PSU and the high-speed modem, which was the cause of most of the Tiger's woes with regard to regulatory approval for connecting to British Telecom's phonelines - it was too fast.

This base unit slid under the monstrous box that held the colour CRT, twin 5.25" floppy drives plus the controller cards for both. These were connected to the Tiger by a set of 50-pin flat cables that plugged in under the front of the machine, BBC Micro-like.

Reviewers praised the graphics capability but were puzzled at the need for production of a new CP/M machine in 1983. In the Personal Computer News review (November 1983) Susan Curran said it could be classed as "a superb upmarket executive machine, The Rover of the micro world perhaps" but also said that "when you're not in graphics mode it's a pretty standard CP/M machine." Quite damning for something that cost close to ukp3000! See my Reviews page for this 4-page review.

This machine came from Pete Todd in Aberystwyth, thanks Pete for helping me achieve a little dream. It's complete and could originally boot to the welcome screen, though whether it still can is unknown. Obviously beyond that we can't do a lot else with it because you need the floppy controller and drives which are in the external box. Only one or two of these are known to exist. Pete tells me he had the chance to show Paul Lancaster pictures of the machine he designed but never saw in production. Excellent! Also it's the 'next one up' to the example that's on display in the cafe at the Centre For Computing History in Cambridge UK. That one is serial 20501 and this one is 20502.

For now, enjoy the pics. I'll update this page with more info as I remember it.

Youtube link to the TIGERDEM graphics demo disks so you can see what the Tiger was capable of.