It is therefore possible to simulate split screen, by setting the soft scroll at the time correct time, then setting it back to 0 immediately after.
===8255===
* When switching port A to input, FF is present on the outputs.
This will cause FF to be output and an invalid PSG register to be selected:
[code]
ld bc,&f400
out (c),c
ld bc,&f6c0
out (c),c
ld bc,&f792
out (c),c
;; At this point FF appears in PPI port A. This selects an invalid PSG register, FF is returned when attempting to read this register.
[/code]
Therefore use this:
[code]
ld bc,&f400
out (c),c
ld bc,&f6c0
out (c),c
ld bc,&f600 ;;; << use inactive
out (c),c
ld bc,&f792
out (c),c
[/code]
===Automatic feeding of sound generator===