r/wADRHEXADRNAMEDescriptionShadowOS
write53774$D20EIRQENPOKMSKInterrupt Request Enableall
read53774$D20EIRQSTPOKMSKInterrupt Request Statusall

Write#

BitFunction
0d
1d
2d
3d
4d
5d
6d
7d

Bit set to "0" (zero) turns interrupt off (disable) Bit set to "1" (one) turns interrupt on (enable)

Read#

BitValueFunctionVector
0$01 1Timer 1 (counted down to zero)VTIMR1 (528; $0210)
1$02 2Timer 2 (counted down to zero)VTIMR2 (530; $0212)
2$04 4Timer 4 (counted down to zero)VTIMR4 (532; $0214 - OS "B" and later ROMs only)
3$08 8Serial output transmission downVSEROC (526; $020E)
4$10 16Serial Output data neededVSEROR (524; $020C)
5$20 32Serial input data readyVESRIN (522; $020A)
6$40 64Other key pressedVKEYBD (520; $0208)
7$80 128Break key pressedBRKKY (566; $0236 - OS "B" and later ROMs only)

see also: Keyboard topics