I/O Map
The following table lists the main I/O definitions of the RCA Studio III & Conic.
| Q | Sound on/off: frequency as defined by tone latch |
| EF1 | CDP 1864 display: display status |
| EF3 | Key pressed on selected port (key pad 1) |
| EF4 | Key pressed on selected port (key pad 2) |
| OUT 1 | CDP 1864 display: step background colour and display on |
| OUT 2 | Select key / port |
| OUT 4 | Tone latch, which sets tone frequency |
| INP 1 | CDP 1861 display: display on |