ADRHEXADRNAMEDescriptionOS
54018$D302PACTLPort A Controlall

BitFunctionDescription
7PA7read only: Interrup status of PROCEED, 1=Interrups
6PA6always 0
5PA5always 1
4PA4always 1
3PA3Cassette player motor control, 0=on, 1=off
2PA21=use Port A for data input/output, 0=define data direction, see below
1PA1always 0
0PA0Interrupt of PROCEED line on/off, set to 0 by OS

To define the data direction of PORT A, set Bit 2 of PACTL to 0. Then write a byte to PORTA, where Bits set to 1 indicate WRITE and Bits set to 0 indicate READ. Normally set to %00000000 (=input).


see also: Controller topics