DOSSEG LOCALS .MODEL SMALL .CODE .386 ASSUME cs:@code, ds:@code IDEAL INCLUDE "PROMOD.INC" ;To Initialize: ; DspReset ; TurnOnSpeaker ; SetSampleRate ; CalcForDMA => call whenever song speed changes ; ;To Start: ; StartTransferDma ; ;To End: ; mov [QuitDMA],1 ; TurnOffSpeaker BufferSeg dw 0 BufferOffset1 dw 0 BufferOffset2 dw 0 Buffer1Size dw 1000 Buffer2Size dw 1000 StereoOn db 0 ;0= stereo is OFF. LptAddress1 dw 3bch LptAddress2 dw 3bch BaseAddress dw 220h IntNumber db 7 DMANumber db 1 DMAPage dw 83h DMAStart dw 2 DmaChartPage dw 87h,83h,82h DMAStartChart db 0,2,6 WhichBuffer dw 4 QuitDma dw 0 ;MoreB db 0,0 ;IPage db 0,0,0,0 ;ILength dw 1,1,1,1 ;IOffset dw 0,0,0,0 STRUC DMAInfo Page dw ?,?,?,? Length dw ?,?,?,? Offset dw ?,?,?,? Next dw 4,4,0,0 ;change 1st to '2' for 2 buffers also 3rd to '6' WBuff dw 3,0,4,0 Current dw 0 ;0 to 3 ENDS DMAInfo DMA DMAInfo <> DmaRoutine dw offset TransferDmaMONO OldInt dd 0 DacBuffOff dw 0 DacBuffLen dw 0 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴 ;==- DMA Interrupt -== PROC DMAINT FAR pusha cli mov dx,[cs:BaseAddress] add dx,0eh in al,dx ;acknowledge interrupt cmp [cs:QuitDma],1 je @@TerminateDMA mov bx,[cs:DMA.Current] ;grab offset mov ax,[cs:bx + DMA.NEXT] ;set up for next buffer mov [cs:DMA.Current],ax mov ah,[BYTE LOW cs:bx + DMA.Page] mov cx,[cs:bx + DMA.Length] mov dx,[cs:bx + DMA.Offset] call [cs:DmaRoutine] mov bx,[cs:DMA.Current] ;grab offset mov ax,[cs:bx + DMA.WBuff] or ax,ax je @@DontSetBuffer mov [cs:WhichBuffer],ax @@DontSetBuffer: mov al,20h out 20h,al ;end of hardware interrupt popa sti iret @@TerminateDMA: mov [cs:QuitDma],0 call UnDoRealInt call HaltDMA jmp @@DontSetBuffer ENDP DMAINT ;====================== ;==- Start Transfer -== ;====================== PROC StartTransferDma NEAR pusha cmp [cs:StereoOn],0 je NoStereo mov ax,130eh ;turn stereo on call SetMixer mov ax,0ff22h ;set master volume = FF call SetMixer mov ax,0ff04h ;set VOC volume = FF call SetMixer mov [cs:DmaRoutine],offset TransferDMASTEREO NoStereo: mov al,[cs:IntNumber] add al,8 cbw shl al,2 mov bx,ax push es sub ax,ax mov es,ax mov ax,[es:bx] mov [WORD LOW cs:OldInt],ax ; Grab the current interrupt mov ax,[es:bx+2] mov [WORD HIGH cs:OldInt],ax ; so we can restore it later pop es mov ax,[cs:DMA.Page] mov ah,al mov cx,[cs:DMA.Length] mov dx,[cs:DMA.Offset] mov al,5 out 0ah,al ;Mask off channel 1 xor al,al out 0ch,al ;Clear byte pointer F/F to lowerbyte mov al,49h out 0bh,al ;Set transfer mode to DAC (ADC = 45h) mov al,dl ;LSB of BASE_ADDRESS out 2,al mov al,dh ;MSB of BASE_ADDRESS out 2,al mov al,ah out 83h,al ;Page Number mov al,cl out 3,al ;LSB of DATA_Length mov al,ch out 3,al ;MSB of DATA_Length mov al,1 out 0ah,al ;Enable Channel 1 mov ax,offset DMAInt call DoRealInt cmp [cs:StereoOn],0 jne @@StartStereo mov al,14h ;function 14h DMAmode 8-bit DAC call Sendcommand mov al,cl ;send LSB of DATALENGTH call SendCommand mov al,ch ;send MSB of DATALENGTH call SendCommand popa ret @@StartStereo: mov al,48h ;data length command call Sendcommand mov al,cl ;send LSB of DATALENGTH call SendCommand mov al,ch ;send MSB of DATALENGTH call SendCommand mov al,91h ;tell it to GO! call SendCommand popa ret ENDP StartTransferDma ;ah= page number ;dx= BASE_ADDRESS ;cx= DATA_LENGTH (-1) ; This function sets up for write only! PROC TransferDmaSTEREO NEAR mov al,5 out 0ah,al ;Mask off channel 1 xor al,al out 0ch,al ;Clear byte pointer F/F to lowerbyte mov al,49h out 0bh,al ;Set transfer mode to DAC (ADC = 45h)_ mov al,dl ;LSB of BASE_ADDRESS out 2,al mov al,dh ;MSB of BASE_ADDRESS out 2,al mov al,ah out 83h,al ;Page Number mov al,cl out 3,al ;LSB of DATA_Length mov al,ch out 3,al ;MSB of DATA_Length mov al,1 out 0ah,al ;Enable Channel 1 mov al,48h ;data length command call Sendcommand mov al,cl ;send LSB of DATALENGTH call SendCommand mov al,ch ;send MSB of DATALENGTH call SendCommand mov al,91h ;tell it to GO! call SendCommand ret ENDP TransferDMASTEREO ;ah= page number ;dx= BASE_ADDRESS ;cx= DATA_LENGTH (-1) ; This function sets up for write only! PROC TransferDmaMONO NEAR mov al,5 out 0ah,al ;Mask off channel 1 xor al,al out 0ch,al ;Clear byte pointer F/F to lowerbyte mov al,49h out 0bh,al ;Set transfer mode to DAC (ADC = 45h)_ mov al,dl ;LSB of BASE_ADDRESS out 2,al mov al,dh ;MSB of BASE_ADDRESS out 2,al mov al,ah out 83h,al ;Page Number mov al,cl out 3,al ;LSB of DATA_Length mov al,ch out 3,al ;MSB of DATA_Length mov al,1 out 0ah,al ;Enable Channel 1 mov al,14h ;function 14h DMAmode 8-bit DAC call Sendcommand mov al,cl ;send LSB of DATALENGTH call SendCommand mov al,ch ;send MSB of DATALENGTH call SendCommand ret ENDP TransferDMAMONO ;ah= SR (Time Constant = 256 - 1,000,000/HZ) PROC SetSampleRate NEAR mov al,40h call SendCommand mov al,ah call SendCommand ret ENDP SetSampleRate PROC TurnOffSpeaker NEAR mov al,0d3h ;turn off speaker call Sendcommand ret ENDP TurnOffSpeaker PROC HaltDMA NEAR mov al,0d0h ;Halt DMA call SendCommand ret ENDP HaltDma ;al = command PROC SendCommand NEAR push dx push ax mov dx,[cs:BaseAddress] add dx,0ch sendcommandloop: in al,dx test al,10000000b jnz sendcommandloop pop ax out dx,al pop dx ret ENDP SendCommand PROC TurnOnSpeaker NEAR mov al,0d1h call SendCommand ret ENDP TurnOnSpeaker ;input- none ;output al=0 successful ; al=1 unsuccessful ;DESTROYED: ax,dx,cx PROC DspReset NEAR mov dx,[cs:baseaddress] add dx,06h mov al,1 out dx,al mov cx,1000 push di rep lodsb ;wait for at least 3�S pop di xor al,al out dx,al add dx,8 ;check WhichBuffer (22eh) mov cx,12000 waitforstat: in al,dx dec cx je errorstat test al,10000000b jz waitforstat mov cx,10000 sub dx,4 ;(22ah) waitforstat2: in al,dx dec cx je errorstat cmp al,0aah jne waitforstat2 mov al,0 ret errorstat: mov al,1 ret ENDP DspReset ;======================== ;==- Start Interrupts -== ;======================== ;cs:ax=location of interrupt PROC DoRealint NEAR pushf ; Push flags push bx push cx push dx mov dx,ax mov al,[cs:IntNumber] add al,8 cbw ; Convrt byte to word shl ax,2 ; Shift w/zeros fill mov bx,ax push es sub ax,ax mov es,ax mov [es:bx],dx mov [es:bx+2],cs pop es mov cl,[cs:IntNumber] mov ah,1 shl ah,cl ; Shift w/zeros fill not ah in al,21h ; port 21h, 8259-1 int IMR and al,ah out 21h,al ; port 21h, 8259-1 int comands pop dx pop cx pop bx popf ; Pop flags ret ENDP DoRealint PROC UnDoREALint NEAR pushf pusha mov al,[cs:IntNumber] add al,8 cbw shl ax,2 mov di,ax push es sub ax,ax mov es,ax mov ax,[WORD LOW cs:OldInt] mov [es:di],ax mov ax,[WORD HIGH cs:OldInt] mov [es:di+2],ax pop es mov cl,[cs:IntNumber] ; (=7) mov ah,1 shl ah,cl ; Shift w/zeros fill in al,21h ; port 21h, 8259-1 int IMR or al,ah out 21h,al ; port 21h, 8259-1 int comands popa popf ; Pop flags ret ENDP UnDoREALint ;STRUC DMAInfo ; Page dw ?,?,?,? ; Length dw ?,?,?,? ; Offset dw ?,?,?,? ; Next dw 4,4,0,0 ;change 1st to '2' for 2 buffers also 3rd to '6' ; Current dw 0 ;0 to 3 ;ENDS DMAInfo PROC CalcForDMA NEAR pushad push ds mov ax,cs mov ds,ax mov [DMA.Next],4 movzx eax,[BufferSeg] movzx edx,[BufferOffset1] ;offset for part1 call MakePage cmp cx,[buffer1size] ;is max less than needed? jb skiplengthset mov cx,[buffer1size] jmp nomoreb1 skiplengthset: mov bx,[buffer1size] sub bx,cx mov [DMA.Next],2 dec bx mov [2 + DMA.Length],bx mov [2 + DMA.Offset],0 mov [BYTE LOW 2 + DMA.Page],ah inc [BYTE LOW 2 + DMA.Page] NoMoreb1: mov [BYTE LOW DMA.Page],ah mov [DMA.Offset],dx dec cx mov [DMA.Length],cx mov [4 + DMA.Next],0 movzx eax,[BufferSeg] movzx edx,[BufferOffset2] ;offset for part1 call MakePage cmp cx,[buffer2size] ;is max less than needed? jb skiplengthset2 mov cx,[buffer2size] jmp nomoreb2 skiplengthset2: mov bx,[buffer2size] sub bx,cx mov [4 + DMA.Next],6 dec bx mov [6 + DMA.Length],bx mov [6 + DMA.Offset],0 mov [BYTE LOW 6 + DMA.Page],ah inc [BYTE LOW 6 + DMA.Page] NoMoreb2: mov [BYTE LOW 4 + DMA.Page],ah mov [4 + DMA.Offset],dx dec cx mov [4 + DMA.Length],cx pop ds popad sti ret ENDP CalcForDMA ;input: eax=segment ; edx=offset ;output: ah=page ; dx=offset ; cx=MAX_LENGTH PROC MakePage NEAR shl eax,4 add edx,eax ;dx = 32bit absolute address ror edx,16 mov ah,dl ;ah= page ror edx,16 mov cx,dx neg cx ret ENDP MakePage ;al = selection#, ah= value PROC SetMixer NEAR push ax dx mov dx,224h out dx,al inc dx jmp $+2 jmp $+2 mov al,ah out dx,al pop dx ax ret ENDP SetMixer ;==== ;==== DAC Stuff... ;==== PROC SetUpInterrupt NEAR pushad push ds mov ax,0 mov ds,ax mov bx,8*4 ;interrupt 8 mov ax,[ds:bx] mov [Word LOW cs:OldInt],ax mov ax,[ds:bx+2] mov [Word HIGH cs:OldInt],ax mov ax,offset TimerInt cmp [cs:StereoOn],0 je @@NoStereo mov ax,offset TimerIntStereo shr [cs:HZ],1 @@NoStereo: cli mov [Word ds:bx],ax mov [ds:bx+2],cs mov al,36h out 43h,al ; timer program mov eax,1193180 movzx ebx,[cs:HZ] ; # of ticks between interrupts xor edx,edx div ebx ; Clock Freq / HZ out 40h,al mov al,ah out 40h,al ; mov al,5ch ; out 21h,al sti pop ds popad ret ENDP SetUpInterrupt PROC RemoveInterrupt NEAR pusha push ds cli mov ax,0 mov ds,ax mov bx,8*4 mov ax,[Word LOW cs:OldInt] mov [ds:bx],ax mov ax,[Word HIGH cs:OldInt] mov [ds:bx+2],ax mov al,36h out 43h,al xor al,al out 40h,al out 40h,al ; mov al,0 ; out 21h,al sti pop ds popa ret ENDP RemoveInterrupt PROC TimerInt FAR pusha push fs mov fs,[cs:BufferSeg] mov di,[cs:DacBuffOff] mov al,[fs:di] mov dx,[cs:LptAddress1] out dx,al inc [cs:DacBuffOff] mov ax,[cs:DacBuffLen] cmp [cs:DacBuffOff],ax jb @@NotOver ;set up for next buffer cmp [cs:WhichBuffer],3 je SetDac3 cmp [cs:WhichBuffer],5 je SetDac3 mov [cs:WhichBuffer],3 mov ax,[cs:BufferOffset2] mov [cs:DacBuffOff],ax add ax,[cs:Buffer2Size] sub ax,2 mov [cs:DacBuffLen],ax jmp @@NotOver SetDac3: mov [cs:WhichBuffer],4 mov ax,[cs:BufferOffset1] mov [cs:DacBuffOff],ax add ax,[cs:Buffer1Size] sub ax,2 mov [cs:DacBuffLen],ax @@NotOver: mov al,20h ;acknowledge hardware interrupt out 20h,al pop fs popa iret ENDP TimerInt PROC TimerIntStereo FAR pusha push fs mov fs,[cs:BufferSeg] mov di,[cs:DacBuffOff] mov al,[fs:di] mov dx,[cs:LptAddress1] out dx,al mov al,[fs:di + 1] mov dx,[cs:LptAddress2] out dx,al add [cs:DacBuffOff],2 mov ax,[cs:DacBuffLen] cmp [cs:DacBuffOff],ax jb @@NotOver ;set up for next buffer cmp [cs:WhichBuffer],3 je @@SetDac3 cmp [cs:WhichBuffer],5 je @@SetDac3 mov [cs:WhichBuffer],3 mov ax,[cs:BufferOffset2] mov [cs:DacBuffOff],ax add ax,[cs:Buffer2Size] sub ax,2 mov [cs:DacBuffLen],ax jmp @@NotOver @@SetDac3: mov [cs:WhichBuffer],4 mov ax,[cs:BufferOffset1] mov [cs:DacBuffOff],ax add ax,[cs:Buffer1Size] sub ax,2 mov [cs:DacBuffLen],ax @@NotOver: mov al,20h ;acknowledge hardware interrupt out 20h,al pop fs popa iret ENDP TimerIntStereo END