Atari XL

Sound and Music
ADVANCED TECHNIQUES
95
The effects you can acheive using the SOUND
command can be quite spectacular, but it is
possible to do more, since this single BASIC
command doesn't offer control over all of the
functions of the POKEY chip. With more
understanding of how the chip operates you can
have a greater influence on the noises it creates
SOUND REGISTERS
Like other chips in the XL, the POKEY chip is
controlled by a number of registers, whose
addresses and functions are shown here.
REGISTER
FUNCTION
53760 ChannelO Frequency
53761
Channel 0 Control
53762
Channel 1 Frequency
53763 Channell Control
53764 Channel 2 Frequency
53765 Channel 2 Control
53766 Channel 3 Frequency
53767 Channel 3 Control
53768 POKEY Control
POKEY Chip Registers