build 129

artwork/HIMARS14.asm

@@ -1,4 +1,4 @@
-;   @com.wudsn.ide.asm.mainsourcefile=scorch.asm
+;   @com.wudsn.ide.asm.mainsourcefile=../scorch.asm
 /***************************************/
 /*  Use MADS http://mads.atari8.info/  */
 /*  Mode: DLI (char mode)              */
@@ -7,7 +7,26 @@
 	;icl "HIMARS14.h"
 	;ICL '../lib/atari.hea'
 
-	org $f0
+	org $80
+
+chn_copy    .ds     9
+chn_pos     .ds     9
+bptr        .ds     2
+cur_pos     .ds     1
+chn_bits    .ds     1
+
+bit_data    .byte   1
+
+.proc get_byte
+    lda song_data+1
+    inc song_ptr
+    bne skip
+    inc song_ptr+1
+skip
+    rts
+.endp
+song_ptr = get_byte + 1
+	
 
 fcnt	.ds 2
 fadr	.ds 2
@@ -47,7 +66,132 @@ pmg	.ds $0300
 	eif
 	eif
 
+song_data
+        ins     'mmm_16.lzs'
+song_end
+
+POKEY = $D200
+
+buffers
+    .ds 256 * 9
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Song Initialization - this runs in the first tick:
+;
+.proc init_song
+
+    ; Example: here initializes song pointer:
+    
+    ;mwa #song_data song_ptr
+
+    ; Init all channels:
+    ldx #8
+    ldy #0
+clear
+    ; Read just init value and store into buffer and POKEY
+    jsr get_byte
+    sta POKEY, x
+    sty chn_copy, x
+cbuf
+    sta buffers + 255
+    inc cbuf + 2
+    dex
+    bpl clear
+
+    ; Initialize buffer pointer:
+    sty bptr
+    sty cur_pos
+    rts
+.endp
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Wait for next frame
+;
+.proc wait_frame
+
+    lda 20
+delay
+    cmp 20
+    beq delay
+.endp
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Play one frame of the song
+;
+.proc play_frame
+    lda #>buffers
+    sta bptr+1
+
+    lda song_data
+    sta chn_bits
+    ldx #8
+
+    ; Loop through all "channels", one for each POKEY register
+chn_loop:
+    lsr chn_bits
+    bcs skip_chn       ; C=1 : skip this channel
+
+    lda chn_copy, x    ; Get status of this stream
+    bne do_copy_byte   ; If > 0 we are copying bytes
+
+    ; We are decoding a new match/literal
+    lsr bit_data       ; Get next bit
+    bne got_bit
+    jsr get_byte       ; Not enough bits, refill!
+    ror                ; Extract a new bit and add a 1 at the high bit (from C set above)
+    sta bit_data       ;
+got_bit:
+    jsr get_byte       ; Always read a byte, it could mean "match size/offset" or "literal byte"
+    bcs store          ; Bit = 1 is "literal", bit = 0 is "match"
+
+    sta chn_pos, x     ; Store in "copy pos"
+
+    jsr get_byte
+    sta chn_copy, x    ; Store in "copy length"
+
+                        ; And start copying first byte
+do_copy_byte:
+    dec chn_copy, x     ; Decrease match length, increase match position
+    inc chn_pos, x
+    ldy chn_pos, x
+
+    ; Now, read old data, jump to data store
+    lda (bptr), y
+
+store:
+    ldy cur_pos
+    sta POKEY, x        ; Store to output and buffer
+    sta (bptr), y
+
+skip_chn:
+    ; Increment channel buffer pointer
+    inc bptr+1
+
+    dex
+    bpl chn_loop        ; Next channel
+
+    inc cur_pos
+.endp
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Check for ending of song and jump to the next frame
+;
+.proc check_end_song
+    lda song_ptr + 1
+    cmp #>song_end
+    ;bne wait_frame
+    lda song_ptr
+    cmp #<song_end
+    ;bne wait_frame
+.endp
+
+end_loop
+    rts
+
+
 main
+    jsr init_song
+
 ; ---	init PMG
 
 	ift USESPRITES
@@ -98,6 +242,12 @@ stop
 	mva #$40 nmien		;only NMI interrupts, DLI disabled
 	cli			;IRQ enabled
 
+    
+    lda #0
+    ldx #8
+@   sta POKEY,x
+    dex
+    bpl @-
 	rts			;return to ... DOS
 
 ; ---	DLI PROGRAM
@@ -266,6 +416,7 @@ x0	lda #$00
 	mwa #DLI.dli_start dliv	;set the first address of DLI interrupt
 
 ;this area is for yours routines
+    jsr play_frame
 
 quit
 	lda regA