| r/w | ADR | HEXADR | NAME | Description | OS |
|---|---|---|---|---|---|
| write/read | 53774 | $D20E | IRQEN, IRQST | Interrupt Request Enable | all |
Write#
| Bit | Function | Vector |
|---|---|---|
| 0 | Timer 1 (counted down to zero) | VTIMR1 (528; $0210) |
| 1 | Timer 2 (counted down to zero) | VTIMR2 (530; $0212) |
| 2 | Timer 4 (counted down to zero) | VTIMR4 (532; $214 - OS "B" ROMs only) |
| 3 | Serial output transmission down | VSEROC (526; 020E) |
| 4 | Serial Output data needed | VSEROR (524; $020C) |
| 5 | Serial input data ready | VESRIN (522; $020A) |
| 6 | Other key pressed | VKEYBD (520; $0208) |
| 7 | Break key pressed |
Bit set to "0" (zero) turns interrupt off (disable) Bit set to "1" (one) turns interrupt on (enable)
Read#
| Bit | Function |
|---|---|
| 0 | d |
| 1 | d |
| 2 | d |
| 3 | d |
| 4 | d |
| 5 | d |
| 6 | d |
| 7 | d |
see also: Keyboard topics
