Bit of an odd machine, this, but held in massive regard by Sinclair collectors. Not a Sinclair at all, it was released round 1987 by Amstrad and is simply a black version of the PC20 that they released in the US.
8086 based with space for an 8087 coprocessor (which this one has), it has 512K RAM, runs MS-DOS 3.3 and Digital Research's GEM desktop if you're connected to one of the optional monitors - the S14-CM colour (from the massively popular PC1640) or the S12-MM green screen (itself identical to the MM12 mono monitor for the Schneider Euro-PC!). If you were a masochist you could also connect the PC200 to a TV though you're restricted to 40 column mode only.
Expansion was by way of 2 half ISA slots allowing connection to a load of 8-bit cards, as long as you didn't mind them poking out the top of the case! Peripherals were limited to the usual Amstrad mouse (black of course), a funky analogue joystick. the ubiquitous dot-matrix printer which I'd gather was the same as the Amstrad DMP-200 and a centronics-style interface and external power connector that was designed to connect a 2nd external diskdrive, again I'd guess Amstrad's own 5 1/4 external unit. Never seen one though.
Bundled software included GEM 3.01, 4 games including Bedlam and Trantos and the 'Sinclair Organiser' which was the usual calendar/planner type thing. I think an Amstrad mouse driver was also included but not necessary if you were running GEM which had its own rodent driver.