An interface which is based on peripheral circuit 8255. In addition there is a RESET button and one Kempston joystick slot. Logic input and output pins are available on a connector FRB 30. Registers of 8255 are mapped as described in following table.
| Registr | Decimal address |
|---|---|
| A | 31 |
| B | 63 |
| C | 95 |
| CWR | 127 |
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