|''Bit 3''||''Bit 2''||''Bit 1''||''Manufacturer Name''
|-
|0||0||0||[[Isp]]
|-
|0||0||1||[[Triumph]]
|-
|0||1||0||[[Saisho]]
|-
|0||1||1||[[Solavox]]
|-
|1||0||0||[[Awa]]
|-
|1||0||1||[[Schneider]]
|-
|1||1||0||[[Orion]]
|-
|1||1||1||[[Amstrad]]
|-
|}
* upper: I/O Mode 0, lower: I/O mode 0,
* upper: output, lower: output
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''Bit''||''Description''||''Usage''
|-
|7||PSG BDIR||PSG function selection
|-
|6||PSG BC1||
|-
|5||Cassette Write data
|-
|4||Cassette Motor Control||set bit to "1" for motor on, or "0" for motor off
|-
|3||Keyboard line||Select keyboard line to be scanned (0-15)
|-
|2||
|-
|1||
|-
|0||
|-
|}
== Programming Examples ==