Programming Sound Cards

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Assembly Source File | 1995-01-01 | 16.9 KB | 440 lines

;══════════════════════════════════════════════════════════════════════════════ ; Play with Cxh/Bxh commands on SoundBlaster 16/16ASP (here 8/mono/signed) ; André Baresel (with some help from Craig Jackson) ;────────────────────────────────────────────────────────────────────────────── ; STATUS: DOES WORK ON SB16 ;────────────────────────────────────────────────────────────────────────────── ; Requirements: 80286, SoundBlaster 16/16ASP (see BASEADDR,DMA channel,IRQ number) ; Resolutions : 8-bit / 4..44khz ; Parameters : none ; Note : Before compiling this call first "VOC2RAW TEST1.VOC /I /S" ; to creat "TEST1.INC" in this case a file with 8bit mono signed data ; ; ■ DSP command 40h ... set sample rate ; ■ DSP command D0h ... Halt Autoinit 8 bit DMA operation ; ■ DSP command D4h ... Continue Autoinit 8 bit DMA operation ; ■ DSP command C6h 10h ... autoinit 8 bit mono data with sign ; .MODEL small .286 ; CONSTANTS ─────────────────────────────────────────────────────────────────── ; SoundBlaster SETUP BASEADDR EQU 0220h ;SoundBlaster base address IRQ7 EQU 15 ;SoundBlaster IRQ DMAchannel EQU 1 ;SoundBlaster DMA channel ; PIC MASKS FOR MASK/DEMASK IRQ PICANDMASK EQU 01111111b ;'AND' PIC mask for clear IRQ7 PICORMASK EQU 10000000b ;'OR' PIC mask for set IRQ7 ; DMA CONTROLLER REGISTERS : WRITEMASK EQU 00ah ;WRITE MASK REGISTER WRITEMODE EQU 00bh ;WRITE MODE REGISTER CLEARFLIPFLOP EQU 00ch PAGE_CHN EQU 083h ;PAGE REGISTER FOR DMAchannel 1 BASE_CHN EQU 002h ;BASEADDRESS REGISTER DMAchannel 1 COUNT_CHN EQU 003h ;COUNT REGISTER DMAchannel 1 ; SAMPLERATE : (if you change it pay attention to maximum samplerate) TIMECONST EQU 165 ; = 10989 Hz (256-1000000/11000) ; DMA WRITE MODE WANTEDMODE EQU 01011000b ; singlemode, autoinit, readmode ;────────────────────────────────────────────────────────────────────────────── ; MACRO DEFINITIONs ;────────────────────────────────────────────────────────────────────────────── STARTUP MACRO ; MASM 5.x COMPATIBILITY __start: mov ax,DGROUP mov ds,ax mov bx,ss sub bx,ax shl bx,004h mov ss,ax add sp,bx ENDM WAITWRITE MACRO LOCAL loopWait,endloop ; Arguments : DX = Status port (BASEADDR+0Ch) ; Returns : n/a ; Destroys : AL push cx xor cx,cx ; need that for slow SBs ! loopWait: dec cx jz endloop in al,dx ; AL = WRITE COMMAND STATUS or al,al js loopWait ; Jump if bit7=1 - writing not allowed endloop: pop cx ENDM WAITREAD MACRO LOCAL loopWait,endloop ; Arguments : DX = Status port (normaly BASEADDR+0Eh) ; Returns : n/a ; Destroys : AL push cx xor cx,cx ; need that for slow SBs ! loopWait: dec cx jz endloop in al,dx ; AL = DATA AVAILABLE STATUS or al,al jns loopWait ; Jump if bit7=0 - no data available endloop: pop cx ENDM RESET_DSP MACRO local SBthere ; Arguments : n/a ; Returns : n/a ; Destroys : DX,AL mov dx,BASEADDR+06h mov al,1 out dx,al ; start DSP reset in al,dx in al,dx in al,dx in al,dx ; wait 3 µsec xor al,al out dx,al ; end DSP Reset add dx,08h ; dx = DSP DATA AVAILABLE WAITREAD sub dx,4 ; dx = DSP Read Data in al,dx cmp al,0aah ; if there is a SB then it returns 0AAh je SBthere jmp RESET_ERROR ; No SB - exit program SBthere: ENDM ;─── End of Macrodefinitions ────────────────────────────────────────────────── .STACK 100h .DATA ;────────────────────────────────────────────────────────────────────────────── ; Creat TEST1.INC with calling "VOC2RAW TEST1.VOC /I /S" or creat your own ; textfile with sampledata -> signed_data_8bit = unsigned_data_8bit-128 SAMPLEBUFFER LABEL BYTE INCLUDE TEST1.INC SAMPLEBUFFEREND LABEL BYTE part db 1 information db 13,10,'DMASTEP8.EXE - play 8bit mono data with sign (that does only work on a' db 13,10,'SB16/SB16ASP) signed data : -128..127 (e.g. amiga samples)' db 13,10,'Pause playing with key "p" and continue it then with any key.' db 13,10,'Stop playing with <ESC>.','$' memerror db 13,10,'Not enough memory to creat the DMA buffer','$' txtpart0 db 13,10,'playing part 0','$' txtpart1 db 13,10,'playing part 1','$' sberror db 13,10,'No SoundBlaster at this BASEADDR ! PROGRAM HALTED.','$' OLDInterruptSEG dw ? OLDInterruptOFS dw ? DMAbufferOFS dw ? DMAbufferPage db ? SAMPLEBUFFERLENGTH = offset SAMPLEBUFFEREND - offset SAMPLEBUFFER ;────────────────────────────────────────────────────────────────────────────── .CODE STARTUP ; FIRST FREE NOT USED MEMORY : mov bx,ss mov ax,es sub bx,ax mov ax,sp add ax,15 shr ax,4 add bx,ax mov ah,04ah int 21h ; NOW ALLOCATE DMABUFFER mov bx,SAMPLEBufferlength+15 shr bx,3 ; cx = samplebufferlength*2/16 ; (count of 16byte blocks) mov ah,48h int 21h jnc enoughmem ; ok got the memory mov dx,offset memerror mov ah,9 int 21h ; WRITE MSG 2 SCRN THAT THERE'S NOT ENOUGH MEM jmp return2dos enoughmem: ; AX = segment of DMA buffer / offset = 0 ;────────────────────────────────────────────────────────────────────────────── ; calculate page and offset for DMAcontroller : ; ; segment*16+offset = 20bit memory location -> upper 4 bits = page ; lower 16 bits = offset ;────────────────────────────────────────────────────────────────────────────── rol ax,4 mov bl,al and bl,00fh and al,0f0h mov [DMABufferOFS],ax mov [DMAbufferPage],bl ;────────────────────────────────────────────────────────────────────────────── ; check for DMApage override : ; ... problem: DMA controller separates memory into 64KB pages, you can only ; transfer data is placed in one page - no page overrides are allowed ;────────────────────────────────────────────────────────────────────────────── ; To solve that : ; creat a DMA buffer with double size you want - if the first part is placed ; on a page border the second part is for sure not ;────────────────────────────────────────────────────────────────────────────── mov cx,SAMPLEBUFFERLENGTH neg ax ; ax = 65536 - ax (bytes left to DMA page border) cmp ax,cx ja nooverride ; USE SECOND PART : neg ax ; ax = offset first data add ax,cx ; use second part inc ax ; cx+1 bytes to next part ;) mov [DMABufferOFS],ax inc [DMABufferPage] ; 2nd part is on next page ! nooverride: ;────────────────────────────────────────────────────────────────────────────── ; Now move the sampledata into the DMAbuffer ; in a MODplayer you'll do that in the IRQ, ; but in our case we only repeat the same sound in the DMAbuffer ;────────────────────────────────────────────────────────────────────────────── ; FIRST CALCULATE THE DOS SEG/OFS FROM DMAPage/OFS mov al,byte ptr [DMABufferOFS] and al,0fh xor ah,ah mov di,ax ; di = offset of DMAbuffer mov ax,[DMABufferOFS] and al,0f0h or al,[DMABufferPage] ror ax,4 mov es,ax ; es = segment of DMABuffer mov si,offset samplebuffer ;NOW COPY IT : ; DS:SI - samples in dataseg ; ES:DI - DMABuffer ; rep movsb RESET_DSP ; WRITE INFOMRATION TO SCREEN : mov dx,offset information mov ah,9 int 21h ; write program information to screen ; ENABLE SB SPEAKERS (for all SBs <SB16) mov dx,BASEADDR+00Ch ;DX = DSP Write Data or Command WAITWRITE mov al,0D1h ; AL = Enable speaker out dx,al ; Output: DSP Write Data or Command ; SETUP IRQ : xor ax,ax mov es,ax ; es to page 0 (Interrupt table) mov si,IRQ7*4 ; si = position in interrupt table ; DISABLE IRQ (if it was enabled somehow) in al,021h and al,PICANDMASK ; SET MASK REGISTER BIT TO DISABLE INTERRUPT out 021h,al ; CHANGE POINTER IN INTERRUPT TABLE mov ax,es:[si] mov [OLDInterruptOFS],ax ; save offset of old interupt vector for restoring mov ax,OFFSET OWN_IRQ mov es:[si],ax ; set offset of new interrupt routine mov ax,es:[si+2] mov [OLDInterruptSEG],ax ; save segment of old interupt vector for restoring mov ax,cs mov es:[si+2],ax ; set segment of new interrupt routine ; CHANGE PIC MASK : in al,021h and al,PICANDMASK ; CLEAR MASK REGISTER BIT TO ENABLE INTERRUPT out 021h,al mov cx,SAMPLEBUFFERLENGTH-1 ;────────────────────────────────────────────────────────────────────────────── ; Setup DMA-controller : ; ; 1st MASK DMA CHANNEL ; mov al,DMAchannel add al,4 out WRITEMASK,al ;────────────────────────────────────────────────────────────────────────────── ; 2nd CLEAR FLIPFLOP ; out CLEARFLIPFLOP,al ;────────────────────────────────────────────────────────────────────────────── ; 3rd WRITE TRANSFER MODE ; mov al,WANTEDMODE add al,DMAchannel out WRITEMODE,al ;────────────────────────────────────────────────────────────────────────────── ; 4th WRITE PAGE NUMBER ; mov al,[DMAbufferPage] out PAGE_CHN,al ;────────────────────────────────────────────────────────────────────────────── ; 5th WRITE DMA BASEADDRESS ; mov ax,[DMABufferOFS] out BASE_CHN,al mov al,ah out BASE_CHN,al ;────────────────────────────────────────────────────────────────────────────── ; 6th WRITE BASECOUNTER = SAMPLELENGTH-1 ; mov al,cl out COUNT_CHN,al mov al,ch out COUNT_CHN,al ;────────────────────────────────────────────────────────────────────────────── ; 7th DEMASK CHANNEL ; mov al,DMAchannel out WRITEMASK,al ;────────────────────────────────────────────────────────────────────────────── ; Setup SoundBlaster : ; ; 1st SET TIMECONSTANT ; mov dx,BASEADDR+00Ch ;DX = DSP Write Data or Command WAITWRITE mov al,040h ;AL = Set timeconstant out dx,al WAITWRITE mov al,TIMECONST out dx,al ;────────────────────────────────────────────────────────────────────────────── ; 2nd USE 8bit MONO UNSIGNED MODE (DSPC C6h 10h XX XXh) ; WAITWRITE mov al,0C6h ;AL = DMA DAC 8bit autoinit out dx,al WAITWRITE mov al,010h ;AL = mono signed data out dx,al mov cx,SAMPLEBUFFERLENGTH shr cx,1 ; generate IRQ every half buffer dec cx WAITWRITE mov al,cl ;AL = LOWER PART SAMPLELENGTH out dx,al WAITWRITE mov al,ch ;AL = HIGHER PART SAMPLELENGTH out dx,al ; TRANSFER STARTs.....NOW..... :) waitloop: mov ah,01 ;AH = Check for character function int 016h ; Interrupt: Keyboard jz waitloop ; wait for a key (sound in background) xor ah,ah ;Read character, flush keypress int 016h ; Interrupt: Keyboard cmp al,'p' ; check for pause key je pause ; ok pause playing cmp al,27 jne waitloop jmp exit pause: ; NOW HALT PLAYING : mov dx,BASEADDR+00Ch ;DX = DSP Write Data or Command WAITWRITE mov al,0D0h out dx,al ; WAIT FOR ANY KEY xor ah,ah ;Read character, flush keypress int 016h ; Interrupt: Keyboard ; NOW CONTINUE PLAYING mov dx,BASEADDR+00Ch ;DX = DSP Write Data or Command WAITWRITE mov al,0d4h out dx,al jmp waitloop exit: RESET_DSP ; RESTORE PIC MASK in al,021h or al,PICORMASK ;<-- SET REGISTER MASK BITS TO DISABLE out 021h,al ; RESTORE IRQ : xor ax,ax mov es,ax ; es to page 0 (Interrupt table) mov si,IRQ7*4 mov ax,[OLDInterruptOFS] mov es:[si],ax ; set old interrupt routine mov ax,[OLDInterruptSEG] mov es:[si+2],ax ; CLEAR KEYBUFFER mov ah,01 int 16h jz return2dos xor ah,ah ;Read character, flush keypress int 016h ; Interrupt: Keyboard ; TERMINATE EXE: return2dos: mov ax,04c00h int 21h ; display information if Soundblaster is not on this baseaddress RESET_ERROR: mov dx,offset sberror mov ah,9 int 21h ; text output jmp return2dos ;────────────────────────────────────────────────────────────────────────────── ; Our own IRQ for detecting buffer half SB currently plays ; It's generated by the SoundBlaster hardware ;────────────────────────────────────────────────────────────────────────────── OWN_IRQ: pusha mov dx,BASEADDR+00Eh ;DX = DSP DATA AVAILABLE (IRQ ACKNOWLEDGE) in al,dx mov ax,@data mov ds,ax mov dx,offset txtpart0 cmp [part],0 je notpart1 mov dx,offset txtpart1 notpart1: mov ah,9 int 21h ; text output neg [part] inc [part] ; part = 1-part result : 0,1,0,1,0,.... mov al,020h out 020h,al ;ACKNOWLEDGE HARDWARE INTERRUPT popa IRET END __start