''Note: Much of this article was originally written by [[CPCLER]], and so any references in the first person ("I", "me", ''etc.'') are probably by him.
[[Image:Kcc top.jpg|right|thumb|250px|The East German KC Compact Computer]]
== UA880 CPU (equivalent to Zilog Z80) ==
The KC compact uses a UA880 CPU , which is a Russian clone of the [[Z80]]. Are It is not confirmed whether there are any actual differences compared to a real Z80?* The . In terms of documentation, the KC Compact System Handbook lists "the opcodes SLL" as documented opcode , INF [a.k.a. IN F,(which is undocumented on Z80C)* The Handbook also lists INF and OUTF opcodes], and describes them to input/output the FLAG register OUTF [a.k.a. OUT (as far as I knowC), the Z80 does NOT work like thatF], instead it'd output ZERO, or input NOTHING, wouldn't it?)whereas these have remained undocumented by Zilog.
== Video ==
* The [[CRTC]] should be more or less same as those used in CPCs. The handbook and schematic say the CRTC is a CM 607. The , but the CRTC used on a real KC Compact is a in CPCLER's an HD6845P.
* The clocks for each mode (0,1 and 2) are derived from the main 16Mhz clock, these then drive the shift registers to output pixels to the display.
* Mode 3 is hardwired to 5V, so it doesn't have a clock. The shift registers are stopped and output the last colour they clocked in. Even if this mode was activated in way of connecting up the clock for Mode 0 it is not decoded the same as on the CPC.: 8 Colours colours are chosen from the 16 colour palette, instead of 4.
* There may be a bug whereby if the border colour is changed rapidly there could be 1 pixel of another colour output. When loading a game which changes the colour of the border, I have seen moving "snow" on the screen. I have seen this effect, but I need to confirm how it is generated.
* The video output doesn't generate luminance, so the KC Compact can't be used with a GT64 or MM14.