|6||PRN.BUSY||Parallel/Printer port ready signal, "1" = not ready, "0" = Ready||Same as on CPC
|-
|5||/EXP||Expansion Port /EXP pin||Printer data bit7Same as on CPC
|-
|4||LK4||Screen Refresh Rate ("1"=50Hz, "0"=60Hz)||Purpose unknown (not same as on CPC?) (set to "1")
* LK1-4 are links on the mainboard ("0" bits are wired to GND). On CPC464,CPC664,CPC6128 and GX4000 they are labeled LK1-LK4, on the CPC464+ and CPC6128+ they are labeled LK101-LK103 (and LK104, presumably?).
* Bit5 bit is connected to (/EXP signal on the expansion port.** On the KC Compact this bit is used to define bit 7 of the printer data (see [[8bit Printer Ports]]).** On the CPC, it is possible to use this bit to define bit 7 of the printer data, so a 8-bit printer port is made, with a hardware modification,** On the CPC this can be used by a expansion device to report it's presence. "1" = device connected, "0" = device not connected. This is not always used by all expansion devices. ''is it used by any expansions?''
Table showing manufacturer name on power-up (CPC and CPC+ only):