|}
=== U82536 CIO (equivalent to Zilog Z8536 CIO ) ===
The Z8536 CIO chip is a counter and I/O chip. In the KC compact system it is used to generate interrupts, access to the parallel printer port, and possibly video control.
When b12 A12 of the I/O address is "0", the Z8536 CIO is selected. Bit b9 A9 and b8 A8 of the I/O address select the registers of the CIO,to avoid conflict with other peripherals the Z8536should be access using:
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''b9Port''||''b8A9''||''A8''||''Register''
|-
|&ECxx||0||0||Port B data register
|-
|&EDxx||0||1||Port C data register
|-
|&EExx||1||0||Control register
|-
|&EFxx||1||1||Port A data register)
|-
|}
(note: b8 A8 is passed through an inverter and this describes the order of the registers in the table compared to the order of the registers in the z8536 CIO datasheet) To avoid conflict with other peripherals the Z8536 should be access using: {|{{Prettytable|width: 700px; font-size: 2em;}}|''Port address''||''Register''|-|&ECxx||Port B data register|-|&EDxx||Port C data register|-|&EExx||control registers|-|&EFxx||Port A data register|-|}
In the KC Compact: