Source Code 1992 March

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Assembly Source File | 1986-05-09 | 9.1 KB | 354 lines

COMMENT ~ SOUND.ASM -- Sound Generation Routines From `BLUEBOOK of ASSEMBLY ROUTINES for the IBM PC & XT' by Christopher L. Morgan Copyright (C) 1984 by The Waite Group, Inc. SOUND.ASM contains a collection of assembly language routines for producing sound in MS/PCDOS 8088 assembly language, using MASM. These routines are FAR PROCEDURES. Contents: --------- DELAY -- Delay for a specified time interval FREQ -- Convert from frequency to period GLISSNDO -- Make a glissando (sliding tone) LINSCALE -- Provide linear scaling PITCH -- Convert from pitch number PLAY -- Play music from a table TONE -- Make a tone TONE_INIT -- Initialize speaker timer TONE_OFF -- Turn off tone TONE_ON -- Turn on tone TONE_SET -- Set the tone on the speaker >>>>> See SOUND.DOC for complete descriptions of these routines <<<<< _____________________________ SOUND ROUTINES_________________________________ It is best to include this data in the source code calling these routines, and then commenting out this next section. ~ DATAS SEGMENT PUBLIC NOTES DW 4186 ;C DW 4435 ;C#/D- DW 4699 ;D DW 4978 ;D#/E- DW 5274 ;E DW 5588 ;F DW 5920 ;F#/G- DW 6272 ;G DW 6645 ;G#/A- DW 7040 ;A DW 7459 ;A#/B- DW 7902 ;B WHOLE DW 0 F_START DW 0 F_END DW 0 DATAS ENDS ;------------------------------------------------------------------------------ CODES SEGMENT PUBLIC DELAY,FREQ,GLISSANDO,LINSCALE,PITCH,PLAY PUBLIC TONE,TONE_INIT,TONE_OFF,TONE_ON,TONE_SET ASSUME CS:CODES,DS:DATAS ;------------------------------------------------------------------------------ ;Routine to set tone ; TONE_INIT PROC FAR PUSH AX ;Save register ; ;Define control bit field parameters for the timer chip SC = 2 ;Use counter 2 RL = 3 ;Mode load period 1 byte/time MODE = 3 ;Square wave generator BCD = 0 ;Not BCD, use binary values ; ;Form control word CNWORD = SC * 40H + RL * 10H + MODE * 2 + BCD ; ;Send control word to 8253 timer chip MOV AL,CNWORD ;Select the above control word OUT 43H,AL ;Send it to the control port POP AX ;Restore register RET TONE_INIT ENDP ;------------------------------------------------------------------------------ ;Routine to select tone ; TONE_SET PROC FAR PUSH AX ;Save register ; ;Load the time period into the timer MOV AL,CL ;Lower byte OUT 42H,AL ;Out to timer MOV AL,CH ;Upper byte OUT 42H,AL ;Out to timer POP AX ;Restore register RET TONE_SET ENDP ;------------------------------------------------------------------------------ ;Routine to turn on tone ; TONE_ON PROC FAR PUSH AX ;Save register ; ;Turn speaker and timer on IN AL,61H ;Get contents of system port B OR AL,3 ;Turn speaker and timer on OUT 61H,AL ;Send out new values to port B POP AX ;Restore register RET TONE_ON ENDP ;------------------------------------------------------------------------------ ;Routine to turn Tone off ; TONE_OFF PROC FAR PUSH AX ;Save register ; ;Turn off timer 2 and speaker IN AL,61H ;Get port B again AND AL,11111100B ;Turn off timer & speaker OUT 61H,AL ;Now do it POP AX ;Restore register RET TONE_OFF ENDP ;------------------------------------------------------------------------------ ;Routine to delay a specified number of milliseconds ; DELAY PROC FAR PUSH CX ;Save register DELAY1: PUSH CX ;Save counter MOV CX,260 ;Timing constant DELAY2: LOOP DELAY2 ;Small loop POP CX ;Restore counter LOOP DELAY1 ;Loop to count milliseconds POP CX ;Restore register RET DELAY ENDP ;------------------------------------------------------------------------------ ;Routine to convert from frequency to period ; FREQ PROC FAR PUSH DX ;Save registers PUSH AX MOV DX,12H ;Upper part of numerator MOV AX,34DEH ;Lower part of numerator DIV CX ;Divide by frequency MOV CX,AX ;The quotient is the output POP AX ;Restore registers POP DX RET FREQ ENDP ;------------------------------------------------------------------------------ ;Routine to make a tone ; TONE PROC FAR PUSH DX ;Save registers PUSH CX PUSH AX ; ;Compute the frequency and set up the tone CALL FREQ ;Convert the frequency CALL TONE_SET ;Set up the tone ; ;Turn on the tone CALL TONE_ON ;Turn it on ; ;Wait for proper delay MOV CX,DX ;Get delay length CALL DELAY ; ;Turn off the tone CALL TONE_OFF ;Turn it off POP AX ;Restore registers POP CX POP DX RET TONE ENDP ;------------------------------------------------------------------------------ ;Routine to scale linearly ; LINSCALE PROC FAR PUSH DX ;Save registers PUSH AX ; ;Compute width MOV AX,F_END ;Get F_END SUB AX,F_START ;Subtract F_START ; ;Multiply width by input parameter MUL CX ;Multiply MOV CX,DX ;Move top part of quotient ; ; into CX ;Add lower limit ADD CX,F_START ;Add F_START POP AX ;Restore registers POP DX RET LINSCALE ENDP ;------------------------------------------------------------------------------ ;Routine to determine pitch ; PITCH PROC FAR PUSH CX ;Save registers PUSH BX PUSH AX MOV AH,0 ;Extend pitch no. to 16 bits MOV CL,12 ;Divisor of 12 DIV CL ;Divide MOV DL,AL ;Quotient determines the octave MOV AL,AH ;Remainder is the pitch within CBW ; 16-bit needed for look up SAL AX,1 ; 2 bytes/item MOV BX,AX ; into BX MOV CX,NOTES[BX] ;Look it up CALL FREQ ;Convert the frequency XCHG CX,DX ;Octave in CL, period in DX NEG CL ;8 - octave = shift count ADD CL,8 SAL DX,CL POP AX ;Restore registers POP BX POP CX RET PITCH ENDP ;------------------------------------------------------------------------------ ;Routine to make glissando ; GLISSANDO PROC FAR PUSH SI ;Save registers PUSH DX PUSH CX PUSH BX PUSH AX MOV F_START,BX ;FROM limit of frequencies MOV F_END,CX ; TO limit of frequencies CALL TONE_ON ;Turn on tone ; ;Set up the loop parameters MOV SI,1 ;Increment for loop CMP BX,CX ;Up or down? JLE GLISS1 ;Skip if up NEG SI ;Decrement freq in the loop GLISS1: MOV CX,BX ;Get the frequency CALL FREQ ;Convert to clock cycles CALL TONE_SET ;Set the tone MOV CX,DX ;Delay parameter > slows slide GLISS2: LOOP GLISS2 CMP BX,F_END ;Check if done JE GLISS3 ;If so, go ADD BX,SI ;Else update the frequency JMP GLISS1 ; ;Turn off the tone GLISS3: CALL TONE_OFF ;Turn it off POP AX ;Restore registers POP BX POP CX POP DX POP SI RET GLISSANDO ENDP ;------------------------------------------------------------------------------ ;Routine to play music ; PLAY PROC FAR PUSH DS ;Save registers PUSH SI PUSH DX PUSH CX PUSH BX PUSH AX ; ;Command pointer is in SI MOV WHOLE,2000 ;Whole note = 2000 milliseconds CLD ;Forward direction ; ;Main loop starts here CHEK_END: ;Get command code and go ; through the cases LODSB ;Get the byte ; ;End command CMP AL,'X' ;Is it End command? JNE CHEK_TEMPO JMP PLAY_XIT ; ;Tempo command CHEK_TEMPO: CMP AL,'T' ;Is it Tempo command? JNE CHEK_NOTE LODSB ;Get the tempo MOV CL,AL ;Set in CX MOV CH,0 MOV AX,60000 ;No. of milliseconds/minute MOV DX,0 ;Clear upper part DIV CX ;Divide into time MOV WHOLE,AX ;No. of milliseconds/whole note JMP CHEK_END ;Back for more ; ;Note command CHEK_NOTE: CMP AL,'N' ;Is it Note command? JNE CHEK_REST LODSB ;Get the pitch CALL PITCH ;Convert MOV CX,DX ; and move result into CX CALL TONE_SET ;Set the frequency CALL TONE_ON ;Turn on the tone MOV CX,WHOLE ;No. of milliseconds/whole note LODSB ;Get the duration MOV AH,AL ;Set up duration as multiplier MOV AL,0 SAL CX,1 ;Scale factor 1 MUL CX ;Multiply MOV CX,DX ;Total count for the note LODSB ;Get style MOV AH,AL ;Set up style as multiplier MOV AL,0 MUL CX ;Multiply by style MOV F_START,DX ;Store count for note SUB CX,DX ;Count for rest MOV F_END,CX ;Store count for rest MOV CX,F_START ;Audible part of note CALL DELAY ;Delay CALL TONE_OFF ;Turn off the tone MOV CX,F_END ;Inaudible part of tone CALL DELAY ;Delay JMP CHEK_END ;Back for more ; ;Rest command CHEK_REST: CMP AL,'R' ;Is it Rest command? JNE PLAY_XIT MOV CX,WHOLE ;No. of milliseconds/whole note LODSB ;Get the duration MOV AH,AL ;Set up duration as multiplier MOV AL,0 SAL CX,1 ;Scale factor of 1 MUL CX ;Multiply MOV CX,DX ;Total count CALL DELAY ;Delay JMP CHEK_END ;Back for more ; ;Anything else end it PLAY_XIT: POP AX ;Restore registers POP BX POP CX POP DX POP SI POP DS RET PLAY ENDP ;----------------------------------------------------------------------------- CODES ENDS ; END ;_____________________________________________________________________________ ;>>>>>Physical EOF SOUND.ASM<<<<<