Sound Engine

Segments

MIDISeg segment PUBLIC 'DATA8'  ; ** Holds MIDI stuff  **
    MIDIBuffer DB 65535 dup(?)
MIDISeg ENDS    

SoundSeg segment PUBLIC 'DATA9' ; ** Holds sound stuff **
    SoundBuffer db 65535 dup(?)
SoundSeg ENDS

Constants

MIDI_1       db 'MIDI/Award.xmi' , 0
MIDI_2       db 'MIDI/End.xmi' , 0
MIDI_3       db 'MIDI/Kalimari.xmi' , 0
MIDI_4       db 'MIDI/Luigi.xmi' , 0
MIDI_5       db 'MIDI/Rainbow.xmi' , 0

================ Sounds ======================

GO          db 'Sound/Go.VOC' , 0
MENU        db 'Sound/Menu.VOC' , 0
ENGINE      db 'Sound/Engine.VOC' , 0 
ALRIGHT1    db 'Sound/Alright1.VOC' , 0
ALRIGHT2    db 'Sound/Alright2.VOC' , 0
ALRIGHT3    db 'Sound/Alright3.VOC' , 0
FINALLAP    db 'Sound/Finallap.VOC' , 0
GETYOU      db 'Sound/Getyou.VOC' , 0
NOTIME      db 'Sound/NoTime.VOC' , 0
COMPLETED   db 'Sound/Completed.VOC' , 0
SKID1       db 'Sound/Skid1.VOC' , 0
SKID2       db 'Sound/Skid2.VOC' , 0
SMASH       db 'Sound/Smash1.VOC' , 0
CLAP        db 'Sound/Theclap.VOC' , 0
THREE       db 'Sound/Three.VOC' , 0
TWO         db 'Sound/Two.VOC' , 0
ONE         db 'Sound/One.VOC' , 0
WOOO        db 'Sound/Wooo.VOC' , 0
SWEAR       db 'Sound/Swear.VOC' , 0


========================================================
                     SOUND VARIABLES
========================================================

=================  SoundBlaster SETUP ==================
BaseAddr        EQU 0220h                      ; SoundBlaster base address
IRQ7            EQU 13                         ; SoundBlaster IRQ (8 +
IRQ)
DMAchannel      EQU 1                          ; SoundBlaster DMA channel

============ PIC MASKS FOR MASK/DEMASK IRQ =============
PICANDMASK         EQU 11011111b               ; 'AND' PIC mask for clear
IRQ7
PICORMASK          EQU 00100000b               ; '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
 Files have to be in the frequency of 10989 Hz
TIMECONST          EQU 165                     ; = 10989 Hz
(256-1000000/11000)

================ DMA WRITE MODE ========================
WANTEDMODE         EQU 01001000b       ; singlemode, autoinit,readmode

Variables

SoundSize dw ? , size of the VOC file
MIDISize dw ? , size of the MIDI file

WriteDSP MACRO X

Owner: Jaime Chu
Purpose: Write to the DSP

It does the following two things
1) Reads the DSP's WRITE BUFFER STATUS port (2xCh) till bit 7
2) Writes the value to the WRITE COMMAND/DATA port (2xCh)

Inputs: X = Data to be written
Outputs: None
Notes: Reference off Programming the SoundBlaster DSP by Mark Feldman

LoadMIDI

Owner: Jaime Chu
Purpose: This procedure loads the MIDI file into the memory using the DOS interrupt 21 command. It opens the file and then it loads into the MIDIBuffer and stores the length of it in MIDISize
Inputs: DX = offset of the string containing the MIDI filename
Outputs:
- MIDI file size is loaded into the MIDIBuffer
- MIDISize - Gets the size of the MIDI file

RegisterXMIDI

Owner: Jaime Chu
Purpose: This routine register an XMIDI file by address for playback
Inputs: AX = 704h , Command number

BX = Offset , Offset portion of far address of XMIDI data
SI = Low len , Low word of length XMIDI data
DI = High Len , High word of length of XMIDI data

Outputs: AX = 0 , Unable to register XMIDI data

AX = 1 , XMIDI file registered resident, This means that the XMIDI file was able to be held entirely in MIDPAK's internal buffer area. The application can throw away the memory associated with this XMIDI file because MIDPAK has made a copy of it itself. This is very useful in virtual memory environments where the applications program does not always have fixed addresses in memory. It also allows MIDPAK to play back MIDI files in the background from DOS.
AX = 2 , XMIDI file was registered to the application. The caller is responsible for making sure that this fixed memory address always contains the data passed.

Notes: Function # 5 from the document MIDPAK writtten by John W.RatCliff

PlayMIDI

Owner: Jaime Chu
Purpose: Plays a sequence from the currently registered Xmidi file
Inputs: AX = 702h, Command number

BX = Sequence number, numbered starting from zero

Outputs: AX = 1, MIDI is being played

AX = 0, MIDI is not available

Notes: Function #3 from the document MIDPAK by John W. Ratcliff

StopMIDI

Owner: Jaime Chu
Purpose: Stops playing current MIDI sequence
Inputs: AX = 705h, Command
Outputs: MIDI stops playing
Notes: Function #6 from the document MIDPAK by John W. RatCliff.

LoadSound

Owner: Jaime Chu
Purpose: This procedure loads the VOC file into the memory segment using the DOS interrupt 21 command. It opens the file and then it loads into the SoundBuffer and stores the length of it in SoundSize
Inputs: DX = offset of the string containing the VOC filename
Outputs: Sound file size is loaded into the SoundBuffer

SoundSize - Gets the size of the VOC file

ResetDSP

Owner: Jaime Chu
Purpose: This function resets the DSP

It does the following.
1) Writes a 1 to the reset port
2) Waits for 3 microseconds
3) Writes a 0 to the reset port
4) Poll the read-buffer status until bit 7 is set
5) Poll the read data port until you receive AAh

Inputs: BaseAddr
Outputs: AL = 0 ; Reset unsucessfully

AL = 1 ; Reset successfully

Notes: This function is based off the DMASTEP7 program. SoundBlaster 16 Programming Document written by Etahn Brodsky was used as reference.

SetupDMA

Owner: Jaime Chu
Purpose: This routine sets up the DMA

It does the following steps
1) Calculates page and offset for the DMAcontroller
2) Mask DMA Channel
3) Clear flipflop
4) Write page number
5) Write DMA base address
6) Write Basecounter = samplelength - 1
7) Demask channel

Inputs: SoundBuffer

SoundSize

Outputs: DMA is set up
Notes: This is based off the DMASTEP7 as well as the SoundBlaster 16 Programming Document written by Ethan Brodsky

LoadSound

Owner: Jaime Chu
Purpose: Sets up the soundblaster and plays the VOC file

It does the following
1) Sets up the timeconstant
2) Uses the highspeed, autoinit DMA (90h)
3) Sets up the playmode and transfers.

Inputs : SoundSize
Outputs: Sound to the speakers
Notes: Based off DMASTEP7 as well as PASCAL source code by Mark Feldman from the Programming the SoundBlaster DSP doc. Refer to the beginning of sound code for DSP commands.