Listing of file='SND.MAC;01' on disk='vmedia/joystick_sound-sector.ccvf'
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; ; SND - SOUND ROUTINE FOR THE AY-3-8910 ; ; VALUES ON ENTRY: ; THE EXTERNAL VARIABLES PITCH AND AMP MUST BE ; SET BEFORE A CALL TO THIS ROUTINE. ; ; NOTE: SNDSET MUST BE CALLED PRIOR TO THIS ROUTINE ; IN ORDER TO SET UP THE CHIP. TO STOP THE ; SOUND OUTPUT, CALL SNDOFF. ; SNDADR EQU 0B0H ;ADDRESS REGISTER ON AY-3-8910, ; AND READ FROM CHIP SNDDAT EQU 0B1H ;LOAD (WRITE) DATA INTO AY-3-8910 EXTRN PITCH,AMP ENTRY SND SND: DI LHLD PITCH MVI A,1 ;OUTPUT COARSE TONE PERIOD FIRST FOR OUT SNDADR ; SMOOTHER CHANGE MOV A,H OUT SNDDAT XRA A OUT SNDADR MOV A,L OUT SNDDAT MVI A,8 ;LOAD AMPLITUDE REGISTER OUT SNDADR LDA AMP OUT SNDDAT EI RET END