| r/w | ADR | HEXADR | NAME | Description | Shadow | OS | 
|---|---|---|---|---|---|---|
| write | 53774 | $D20E | IRQEN | POKMSK | Interrupt Request Enable | all | 
| read | 53774 | $D20E | IRQST | POKMSK | Interrupt Request Status | all | 
Write#
| Bit | Function | 
|---|---|
| 0 | d | 
| 1 | d | 
| 2 | d | 
| 3 | d | 
| 4 | d | 
| 5 | d | 
| 6 | d | 
| 7 | d | 
Bit set to "0" (zero) turns interrupt off (disable) Bit set to "1" (one) turns interrupt on (enable)
Read#
| Bit | Value | Function | Vector | 
|---|---|---|---|
| 0 | $01 1 | Timer 1 (counted down to zero) | VTIMR1 (528; $0210) | 
| 1 | $02 2 | Timer 2 (counted down to zero) | VTIMR2 (530; $0212) | 
| 2 | $04 4 | Timer 4 (counted down to zero) | VTIMR4 (532; $0214 - OS "B" and later ROMs only) | 
| 3 | $08 8 | Serial output transmission down | VSEROC (526; $020E) | 
| 4 | $10 16 | Serial Output data needed | VSEROR (524; $020C) | 
| 5 | $20 32 | Serial input data ready | VESRIN (522; $020A) | 
| 6 | $40 64 | Other key pressed | VKEYBD (520; $0208) | 
| 7 | $80 128 | Break key pressed | BRKKY (566; $0236 - OS "B" and later ROMs only) | 
see also: Keyboard topics
