The keyboard matrix of the KC compact supports all the keys of the CPC, but the following keys are not on the keyboard: F5, F6,F7,F8,F9
== KP580BB55 PIO (equivalent to 8255 PIO Port B Input ) == Used (almost) identically as the CPC's [[8255]]. PIO Port B is slightly different:
{|{{Prettytable|width: 700px; font-size: 2em;}}
|5||/EXP (identical to CPC)
|-
|4||1 (+5v) (would be LK4 screen refresh rate in CPC) (but isn't like so in KC Compact?)
|-
|3||1 (+5v) (would be LK3 manufacturer ID in CPC)
|-
|2||0 (0v) (would be LK2 manufacturer ID in CPC)
|-
|1||/TEST(would be LK1 manufacturer ID in CPC)
|-
|0||VSYNC (identical to CPC)
|-
|}
* Note: The KC System Handbook accidently calls the chip "KP580B55", however, the correct name is "KP580BB55" (with double "B").
== U82536 CIO (equivalent to Zilog Z8536 CIO) ==