Listing of file='AYSND.MAC;01' on disk='vmedia/joystick_sound-sector.ccvf'
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; ; ROUTINES FOR THE AY-3-8910 SOUND CHIP ; ; VALUES ON ENTRY: ; A - AMPLITUDE (1-15) ; HL - DEFAULT PITCH (1-4095) ; THE PUBLIC VARIABLES PITCH AND AMP CAN BE ALTERED ; BEFORE EACH CALL TO SND, WHICH CHANGES THE TONE. ; ; RETURNS: ; NOTHING ; ; DESTROYS: ; ALL REGISTERS ; SNDADR EQU 0B0H ;ADDRESS REGISTER ON AY-3-8910, ; AND READ FROM CHIP SNDDAT EQU 0B1H ;LOAD (WRITE) DATA INTO AY-3-8910 ; ; SNDSET - SET UP SOUND CHIP FOR CHANNEL "A" ; ; NOTE: THIS ROUTINE DISABLES EVERYTHING EXCEPT PURE ; TONE ON CHANNEL "A" ; ENTRY SNDSET PUBLIC PITCH,AMP SNDSET: SHLD PITCH STA AMP MVI B,14 CLRREG: MOV A,B ;CLEAR ALL REGISTERS IN SOUND CHIP DCR A OUT SNDADR XRA A OUT SNDDAT DCR B JNZ CLRREG MVI A,7 OUT SNDADR MVI A,3EH ;ENABLE TONE ON "A" ONLY OUT SNDDAT RET PITCH: DW 50 AMP: DB 15 ; ; SNDOFF - TURN SOUND OFF ON CHANNEL "A" ; ENTRY SNDOFF SNDOFF: MVI A,8 OUT SNDADR XRA A OUT SNDDAT RET END