I/O Port Address Map
| Port | Bit | ||||
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | |
| &FEFE | Shift | Z | X | C | V |
| &FDFE | A | S | D | F | G |
| &FBFE | Q | W | E | R | T |
| &F7FE | 1 | 2 | 3 | 4 | 5 |
| &EFFE | 0 | 9 | 8 | 7 | 6 |
| &DFFE | P | O | I | U | Y |
| &BFFE | Enter | L | K | J | H |
| &7FFE | Space | Sym | M | N | B |
> Hover or click a key to inspect...
READY
The ZX Spectrum reads its keyboard via 8 I/O port addresses. Each port reads a half-row of 5 keys across bits 0–4 (active low). A bit reads 0 when its key is pressed, 1 when released.