Microcolour terminal

Has anyone ever come across a 'Microcolour' terminal? It was made in the UK by Microvitec, who were better known for monitors (often BBC micros were used iwth Microvitec Cub monitors). I have a couple of the Microcolour base units here, no monitors or keyboards. Here's what I've discovered so far... On the rear are connectors for 'Host' (DB25 plug), 'Printer 1' (DB25 socket), 'Printer 2' (DB25 socket), Monitor (DB25 plug), Keyboard (DE9 socket), mains in/out (mormal IEC connectors, a couple of fuses and the on/off switch. The only feature on the front is a green power-on LED. Insdie is a PSU (the 2 units I have differ in the PSU design, but that's not vert important at the momnet0 nd a crdcage containg 3 PCBs (with aslot for a 4th). These plug into a backplane at the front fo the machine using 64 pin A+B DIN41612 connectors. The loweremost PCB carries the Host, Printer 1 and Keyboard connectors. On this board are the processor (6809), EPROMs, RAM (some of which is battery-backed -- I have removed the leaking NiCdsm there is no other damage), 4 6551 serial chips (for the printer 1 port, which is RS232 DTE, even though it's on a socket :-(), the keyboard port (TTL level), and the host port (it uses 2 6551s for this so yuo can have split baud rates I guess), a 6821 (used at least for the Printer 2 port which is thus a parallel interface, a cable rund from a SIL header on the PCB to the DB25 socket o nthe chassis), etc. One of the EPROMs has a label 'Regis' which seems to suggest what protocol it may use. The other 2 boards are video-relates. One seems to be text video (6845, several 6116 RAMs in a row on one edge, another couple of 6116s which may well be programmable character generator, there's no EPROM on this board), and lots of TTL. There's a 10 pin header which is linked ot part of the monitor connector. The last PCB seems to be graphics related. It contains 128K of DRAM, some 74S189 SRAMs for a oolour palette and again lots of TTL. There's a 15 pin header that links to the montior conecetor. Now for the monitor connector. It's a DB25 plug. One pin is not fitted, one is wired to chassis ground. 9 of the remainder go to the text PCB (one pin on the header is not used), the remaining 14 go to the graphics board (again one pin on the header is not used). Now fo the odd thing. All those signals are TTL level. The output of the graphics board (12 pins on the header) are the outputs of those palette RAMs. In other words 12 bits digital (I asusme 4 bits each for R,G,B). The otuput fo the text board is similarly a 4 bit value (I think). And of course there are 2 sync signals, which I could identify. Vsync is 50Hz (not too suprising), HSync is 21.8kHz. In other words, EGA rates .Sothis thing used a specail EGA-like monitor with many more input bits. I suspect I am goign to start by hooking up a normal EGA monitor (assuming I can find one, I think I have a 5154 around here) to see if I can get some output, albiet with fewer colours than I should have and then try modifying such a montiro t oincrease the numebr of bits on the DACs. As for the keyhoard, at least it's synchronous serial (of the pins on the DE9, there's TTL level TxD and RxD, ground, +5V, +12V, -12V). I have no idea of the baud rate, etc, but if necesary I cna use a logic analyser to see how it initialises the appropriate 6551. -tony