* upper: I/O Mode 0, lower: I/O mode 0,
* upper: output, lower: output
{|{{Prettytable|width: 700px; font-size: 2em;}}
|-
|0||
|-
|}
PSG function selection:
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''Bit 7''||''Bit 6''||''Function''
|-
|0||0||Inactive
|-
|0||1||Read from selected PSG register
|-
|1||0||Write to selected PSG register
|-
|1||1||Select PSG register
|-
|}