Initial version 1.0.

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2022 chrisly42
+Copyright (c) 2022 Chris 'platon42' Hodges <chrisly@platon42.de>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,2 +1,101 @@
-# PretrackerRaspberryCasket
+# Raspberry Casket
 A fast and small open source Pretracker replayer
+
+## Raspberry Casket Player V1.0 (26-Dec-2022)
+
+Provided by Chris 'platon42' Hodges <chrisly@platon42.de>
+
+Rewritten by *platon42/Desire* based on a resourced, binary identical
+version of the original Pretracker V1.0 replayer binary provided
+by *hitchhikr* (thanks!), originally written in C by *Pink/Abyss*.
+
+This version is the hard work of reverse engineering all the
+offsets, removing all the C compiler crud, removing dead and
+surplus code (maybe artefacts from earlier ideas that did nothing),
+optimizing the code where possible. This resulted in both reduced
+size of the replayer, faster sample calculation and speeding the
+tick routine up significantly.
+
+I also added a few optional features that come in handy, such as
+song-end detection and precalc progress support.
+
+It took me more than a month and it was not fun.
+
+Also: Open source. It's 2022, keeping the code closed is just not
+part of the demoscene spirit (anymore?), at least for a replayer.
+
+Also note that this is not the final state of the source code.
+I could go over many places still and try to rework them.
+But I wanted the code to be out in public.
+
+### Verification
+
+The replayer has been verified on about 60 Pretracker tunes to
+create an identical internal state for each tick and identical
+samples (if certain optimizations switches are disabled).
+
+I might have introduced bugs though. If you find some problems,
+please let me know under chrisly@platon42.de. Thank you.
+
+### Usage
+
+The new replayer comes as a drop-in binary replacement if you wish.
+In this case you will get faster sample generation (about 12%
+faster on 68000) and about 45% less CPU time spent. However, you
+won't get stuff as song-end detection and precalc progress this way.
+This mode uses the old CPU DMA wait that takes away 8 raster lines.
+
+If you want to get rid of the unnecessary waiting, you can switch
+to a copper driven audio control. If you want to use the top portion
+of the copperlist for this, you probably need to double buffer it.
+Otherwise, you could also position the copperlist at the end of
+the display and use single buffering if you call the tick routine
+during the vertical blank.
+
+Please use the documented sizes for the `MySong` and `MyPlayer` data
+structures, which are the symbols `sv_SIZEOF` and `pv_SIZEOF`
+respectively (about 2K and 12K with volume table).
+
+The source needs two common include files to compile (`custom.i` and
+`dmabits.i`). You should leave assembler optimizations enabled.
+
+1. (If you're using copper list mode, call `pre_PrepareCopperlist`.)
+2. Call `pre_SongInit` with
+   - a pointer to `MySong` (`mv_SIZEOF`) in `a1` and
+   - the music data in `a2`.
+   It will return the amount of sample memory needed in `d0`.
+3. Then call `pre_PlayerInit` with
+   - a pointer to `MyPlayer` (`pv_SIZEOF`) in `a0`
+   - a pointer to chip memory sample buffer in `a1`
+   - the pointer to `MySong` in `a2`
+   - a pointer to a longword for progress information or null in `a3`
+   This will create the samples, too.
+4. After that, regularly call `pre_PlayerTick` with `MyPlayer` in `a0`
+   and optionally the copperlist in a1 if you're using that mode).
+
+### Size
+
+The original C compiled code was... just bad. The new binary is
+about 1/3 of the original one.
+
+The code has been also optimized in a way that it compresses better.
+The original code compressed with *Blueberry's* Shrinkler goes from
+18052 bytes down to 9023 bytes.
+
+Raspberry Casket, depending on the features compiled in, is about
+6374 bytes and goes down to ~4410 bytes (in isolation).
+
+So this means that the optimization is not just "on the outside".
+
+### Timing
+
+Unfortunately, the replayer is still pretty slow and has high
+jitter compared to other standard music replayers.
+
+This means it may take up to 33 raster lines (14-19 on average)
+which is significant more than a standard Protracker replayer
+(the original one could take about 60 raster lines worst case and
+about 34 on average!).
+
+Watch out for *Presto*, the [LightSpeedPlayer](https://github.com/arnaud-carre/LSPlayer) variant that should
+solve this problem.

binaries/readme.txt

@@ -0,0 +1,5 @@
+This file "raspberry_casket.bin" can replace the original "player.bin"
+provided that you used the 16 KB + 16 KB allocation for player
+variables as in the original player.
+
+It has been assembled from src/drop_in_replacement.asm.

example/plastic_duff.asm

@@ -0,0 +1,203 @@
+; Framework settings
+
+FW_STANDALONE_FILE_MODE     = 1 ; enable standalone (part testing)
+FW_HD_TRACKMO_MODE          = 0 ; DO NOT CHANGE (not supported for standalone mode)
+
+FW_MUSIC_SUPPORT            = 0
+FW_MUSIC_PLAYER_CHOICE      = 0 ; 0 = None, 1 = LSP, 2 = LSP_CIA, 3 = P61A, 4 = Pretracker Turbo, 5 = Pretracker Copper
+FW_LMB_EXIT_SUPPORT         = 1 ; allows abortion of intro with LMB
+FW_MULTIPART_SUPPORT        = 0 ; DO NOT CHANGE (not supported for standalone mode)
+FW_DYNAMIC_MEMORY_SUPPORT   = 0 ; enable dynamic memory allocation. Otherwise, use fw_ChipMemStack/End etc fields.
+FW_MAX_MEMORY_STATES        = 4 ; the amount of memory states
+FW_TOP_BOTTOM_MEM_SECTIONS  = 0 ; allow allocations from both sides of the memory
+FW_64KB_PAGE_MEMORY_SUPPORT = 0 ; allow allocation of chip memory that doesn't cross the 64 KB page boundary
+FW_MULTITASKING_SUPPORT     = 0 ; enable multitasking
+FW_ROUNDROBIN_MT_SUPPORT    = 0 ; enable fair scheduling among tasks with same priority
+FW_BLITTERTASK_MT_SUPPORT   = 0 ; enable single parallel task during large blits
+FW_MAX_VPOS_FOR_BG_TASK     = 300 ; max vpos that is considered to be worth switching to a background task, if any
+FW_SCRIPTING_SUPPORT        = 0 ; enable simple timed scripting functions
+FW_PALETTE_LERP_SUPPORT     = 0 ; enable basic palette fading functions
+FW_YIELD_FROM_MAIN_TOO      = 0 ; adds additional code that copes with Yield being called from main code instead of task
+FW_VBL_IRQ_SUPPORT          = 0 ; enable custom VBL IRQ routine
+FW_COPPER_IRQ_SUPPORT       = 1 ; enable copper IRQ routine support
+FW_AUDIO_IRQ_SUPPORT        = 0 ; enable audio IRQ support (unimplemented)
+FW_VBL_MUSIC_IRQ            = 0 ; enable calling of VBL based music ticking (disable, if using CIA timing!)
+FW_BLITTERQUEUE_SUPPORT     = 0 ; enable blitter queue support
+FW_A5_A6_UNTOUCHED          = 1 ; speed up blitter queue if registers a5/a6 are never changed in main code
+
+FW_LZ4_SUPPORT              = 0 ; compile in LZ4 decruncher
+FW_DOYNAX_SUPPORT           = 0 ; compile in doynax decruncher
+FW_ZX0_SUPPORT              = 0 ; compile in ZX0 decruncher
+
+CHIPMEM_SIZE = 4
+FASTMEM_SIZE = 4
+
+; Raspberry Casket settings
+PRETRACKER_SUPPORT_V1_5 = 1
+PRETRACKER_PARANOIA_MODE = 0
+PRETRACKER_DUBIOUS_PITCH_SHIFT_FOR_DELAYED_TRACK = 0
+PRETRACKER_KEEP_JUMP_TABLE = 0
+PRETRACKER_SONG_END_DETECTION = 0
+PRETRACKER_PROGRESS_SUPPORT = 0
+PRETRACKER_FASTER_CODE = 1
+PRETRACKER_VOLUME_TABLE = 1
+PRETRACKER_BUGFIX_CODE = 1
+PRETRACKER_DONT_TRASH_REGS = 0
+PRETRACKER_COPPER_OUTPUT = 1
+
+DEBUG_DETAIL	SET	    0
+
+NEWAGE_DEBUG    = 1
+
+        include "../frameworkng/framework.i"
+
+        STRUCTURE	PartData,fw_SIZEOF
+		ULONG	pd_Progress
+        ULONG   pd_SamplesSize
+        
+        ULONG	pd_StartVHPos
+		ULONG	pd_MinClocks
+		ULONG	pd_SumClocks
+		ULONG	pd_MaxClocks
+		UWORD	pd_SumCount
+		STRUCT  pd_MyPlayer,pv_SIZEOF
+		STRUCT  pd_MySong,sv_SIZEOF
+        LABEL   pd_SIZEOF
+
+        include "../frameworkng/framework.asm"
+
+entrypoint:
+
+        IFNE    PRETRACKER_COPPER_OUTPUT
+        lea     pld_pretracker_copperlist,a0
+        move.w  #300,d0
+        bsr     pre_PrepareCopperlist
+		move.l	d1,(a0)	; terminate copperlist
+        ENDC
+
+        ;lea     pd_MyPlayer(a6),a0
+        lea		pd_MySong(a6),a1
+        move.l  #pretracker_data,a2
+        PUTMSG  10,<"NewInit songInit %p, %p, %p">,a0,a1,a2
+        PUSHM   a5/a6
+        bsr		pre_SongInit
+		POPM
+		PUTMSG	10,<"Return val %ld">,d0
+        move.l  d0,pd_SamplesSize(a6)
+
+        CALLFW  VSync
+        move.w  fw_FrameCounter(a6),d6
+        lea		pd_MyPlayer(a6),a0
+        move.l  #lsp_samples,a1
+		lea		pd_MySong(a6),a2
+        sub.l   a3,a3
+        PUTMSG  10,<"NewInit playerInit %p, %p, %p">,a0,a1,a2
+        PUSHM   d6/a5/a6
+        bsr		pre_PlayerInit
+        POPM
+		move.w	fw_FrameCounter(a6),d1
+		sub.w	d6,d1
+		PUTMSG	10,<"Return val %ld, Frames: %d">,d0,d1
+
+        move.l	#100000,pd_MinClocks(a6)
+
+        lea     pld_copperlist,a0
+        CALLFW  SetCopper
+
+        lea		.track_time(pc),a0
+		move.l	a0,fw_CopperIRQ(a6)
+
+.loop   moveq.l #63,d0
+        and.w   fw_FrameCounter(a6),d0
+        bne.s   .nooutput
+		move.l	pd_SumClocks(a6),d0
+		divu	pd_SumCount(a6),d0
+        PUTMSG	10,<"Min %d   Max %d   Average %d">,pd_MinClocks(a6),pd_MaxClocks(a6),d0
+.nooutput
+		CALLFW  VSync
+        bra.s   .loop
+
+.track_time
+		move.w	#$5ff,color(a5)
+		move.l	vposr(a5),pd_StartVHPos(a6)
+        PUSHM	d1-d7/a0-a6
+        lea		pd_MyPlayer(a6),a0
+        lea     pld_pretracker_copperlist,a1
+		bsr		pre_PlayerTick
+		POPM
+        move.l	vposr(a5),d0
+		move.w	#$f6f,color(a5)
+
+        PUSHM	d1-d4
+		and.l	#$1ffff,d0
+		move.l	pd_StartVHPos(a6),d1
+		and.l	#$1ffff,d1
+		moveq.l	#0,d3
+		move.b	d0,d3
+		lsr.l	#8,d0
+		mulu	#227,d0
+		add.l	d3,d0
+
+        moveq.l	#0,d4
+		move.b	d1,d4
+		lsr.l	#8,d1
+		mulu	#227,d1
+		add.l	d4,d1
+		PUTMSG	20,<"Startclocks %ld Clocks %ld">,d1,d0
+		sub.l	d1,d0
+		cmp.l	pd_MinClocks(a6),d0
+		bge.s	.nomin
+		move.l	d0,pd_MinClocks(a6)
+.nomin
+		cmp.l	pd_MaxClocks(a6),d0
+		ble.s	.nomax
+		move.l	d0,pd_MaxClocks(a6)
+.nomax
+		add.l	d0,pd_SumClocks(a6)
+		addq.w	#1,pd_SumCount(a6)
+		POPM
+		rts
+
+        include "../frameworkng/musicplayers/raspberry_casket.asm"
+
+;--------------------------------------------------------------------
+
+        section "pld_copper",data,chip
+
+pld_copperlist:
+        COP_MOVE diwstrt,$2c81	        ; window start
+        COP_MOVE diwstop,$2cc1	        ; window stop
+        COP_MOVE ddfstrt,$0038	        ; bitplane start
+        COP_MOVE ddfstop,$00d0	        ; bitplane stop
+
+        COP_MOVE bplcon3,$0c00
+pld_fmode:
+        COP_MOVE fmode,$0000            ; fixes the aga modulo problem
+        COP_MOVE bplcon0,$0200
+
+		COP_MOVE color,$fff
+		;dc.w	$0180,$0fff,$01a2,$0eee,$01a4,$0edd,$01a6,$0e9b
+		;dc.w	$01a8,$0e69,$01aa,$0b78,$01ac,$0d57,$01ae,$0a56
+		;dc.w	$01b0,$0a34,$01b2,$0934,$01b4,$0923,$01b6,$0612
+		;dc.w	$01b8,$0211,$01ba,$0000
+
+        COP_WAITLINE $80
+        COP_MOVE intreq,INTF_SETCLR|INTF_COPER
+
+        COP_WAITRAST $ff,$de
+pld_pretracker_copperlist
+		COP_END
+        ds.l    36
+        COP_END
+
+		;incbin	"../data/pretracker/raspberry_casket64x64.SPR"
+		
+        section "pretracker_data",data
+pretracker_data:
+		incbin  "../data/pretracker/Pink - Plastic Dove (from Coda Intro).prt"
+
+        section "lsp_samples",data,chip
+lsp_samples:
+        ds.b        19522
+
+        END

example/readme.txt

@@ -0,0 +1,23 @@
+This is a bare-bone example on how to use the replayer.
+It features Pink's song Plastic Dove (from the Coda Intro).
+
+Even though it features the full replayer code and tune,
+the replayer including my demo framework and the song only
+takes a mere 6560 bytes (shrinkled), which is even smaller
+than the new streaming replayer used in Pink's new streaming
+player demonstrated (closed source) in
+
+https://www.pouet.net/prod.php?which=91551
+
+which is 6860 bytes.
+
+The Raspberry Casket replayer takes an average of 14
+rasterlines while Pink's new streaming player takes
+only about 10 rasterlines.
+
+However, the song is not really busy and very short (1:35).
+This means, regarding file size, this streaming format will
+always lose against storing the full song data.
+
+But anyway, I think I will create a compact streaming
+format later next year (2023), too.

includes/hardware/custom.i

@@ -0,0 +1,154 @@
+	IFND	HARDWARE_CUSTOM_I
+HARDWARE_CUSTOM_I	SET	1
+**
+**	$VER: custom.i 39.1 (18.09.92)
+**	Includes Release 39.108
+**
+**	Offsets of Amiga custom chip registers
+**
+**	(C) Copyright 1985-1992 Commodore-Amiga, Inc.
+**	    All Rights Reserved
+**
+
+*
+* do this to get base of custom registers:
+*  XREF _custom;
+*
+
+bltddat     EQU   $000
+dmaconr     EQU   $002
+vposr	    EQU   $004
+vhposr	    EQU   $006
+dskdatr     EQU   $008
+joy0dat     EQU   $00A
+joy1dat     EQU   $00C
+clxdat	    EQU   $00E
+
+adkconr     EQU   $010
+pot0dat     EQU   $012
+pot1dat     EQU   $014
+potinp	    EQU   $016
+potgor	    EQU   potinp
+serdatr     EQU   $018
+dskbytr     EQU   $01A
+intenar     EQU   $01C
+intreqr     EQU   $01E
+
+dskpt	    EQU   $020
+dsklen	    EQU   $024
+dskdat	    EQU   $026
+refptr	    EQU   $028
+vposw	    EQU   $02A
+vhposw	    EQU   $02C
+copcon	    EQU   $02E
+serdat	    EQU   $030
+serper	    EQU   $032
+potgo	    EQU   $034
+joytest     EQU   $036
+strequ	    EQU   $038
+strvbl	    EQU   $03A
+strhor	    EQU   $03C
+strlong     EQU   $03E
+
+bltcon0     EQU   $040
+bltcon1     EQU   $042
+bltafwm     EQU   $044
+bltalwm     EQU   $046
+bltcpt	    EQU   $048
+bltbpt	    EQU   $04C
+bltapt	    EQU   $050
+bltdpt	    EQU   $054
+bltsize     EQU   $058
+bltcon0l    EQU   $05B		; note: byte access only
+bltsizv     EQU   $05C
+bltsizh     EQU   $05E
+
+bltcmod     EQU   $060
+bltbmod     EQU   $062
+bltamod     EQU   $064
+bltdmod     EQU   $066
+
+bltcdat     EQU   $070
+bltbdat     EQU   $072
+bltadat     EQU   $074
+
+deniseid    EQU   $07C
+dsksync     EQU   $07E
+
+cop1lc	    EQU   $080
+cop2lc	    EQU   $084
+copjmp1     EQU   $088
+copjmp2     EQU   $08A
+copins	    EQU   $08C
+diwstrt     EQU   $08E
+diwstop     EQU   $090
+ddfstrt     EQU   $092
+ddfstop     EQU   $094
+dmacon	    EQU   $096
+clxcon	    EQU   $098
+intena	    EQU   $09A
+intreq	    EQU   $09C
+adkcon	    EQU   $09E
+
+aud	    EQU   $0A0
+aud0	    EQU   $0A0
+aud1	    EQU   $0B0
+aud2	    EQU   $0C0
+aud3	    EQU   $0D0
+
+* AudChannel
+ac_ptr	    EQU   $00	; ptr to start of waveform data
+ac_len	    EQU   $04	; length of waveform in words
+ac_per	    EQU   $06	; sample period
+ac_vol	    EQU   $08	; volume
+ac_dat	    EQU   $0A	; sample pair
+ac_SIZEOF   EQU   $10
+
+bplpt	    EQU   $0E0
+
+bplcon0     EQU   $100
+bplcon1     EQU   $102
+bplcon2     EQU   $104
+bplcon3     EQU   $106
+bpl1mod     EQU   $108
+bpl2mod     EQU   $10A
+bplcon4     EQU   $10C
+clxcon2     EQU   $10E
+
+bpldat	    EQU   $110
+
+sprpt	    EQU   $120
+
+spr	    EQU   $140
+
+* SpriteDef
+sd_pos	    EQU   $00
+sd_ctl	    EQU   $02
+sd_dataa    EQU   $04
+sd_dataB    EQU   $06
+sd_SIZEOF   EQU   $08
+
+color	    EQU   $180
+
+htotal	    EQU   $1c0
+hsstop	    EQU   $1c2
+hbstrt	    EQU   $1c4
+hbstop	    EQU   $1c6
+vtotal	    EQU   $1c8
+vsstop	    EQU   $1ca
+vbstrt	    EQU   $1cc
+vbstop	    EQU   $1ce
+sprhstrt    EQU   $1d0
+sprhstop    EQU   $1d2
+bplhstrt    EQU   $1d4
+bplhstop    EQU   $1d6
+hhposw	    EQU   $1d8
+hhposr	    EQU   $1da
+beamcon0    EQU   $1dc
+hsstrt	    EQU   $1de
+vsstrt	    EQU   $1e0
+hcenter     EQU   $1e2
+diwhigh     EQU   $1e4
+fmode	    EQU   $1fc
+
+   ENDC  !HARDWARE_CUSTOM_I

includes/hardware/dmabits.i

@@ -0,0 +1,49 @@
+	IFND	HARDWARE_DMABITS_I
+HARDWARE_DMABITS_I	SET	1
+**
+**	$VER: dmabits.i 39.1 (18.09.92)
+**	Includes Release 39.108
+**
+**	include file for defining dma control stuff
+**
+**	(C) Copyright 1985-1992 Commodore-Amiga, Inc.
+**	    All Rights Reserved
+**
+
+* write definitions for dmaconw
+DMAF_SETCLR    EQU   $8000
+DMAF_AUDIO     EQU   $000F  ; 4 bit mask
+DMAF_AUD0      EQU   $0001
+DMAF_AUD1      EQU   $0002
+DMAF_AUD2      EQU   $0004
+DMAF_AUD3      EQU   $0008
+DMAF_DISK      EQU   $0010
+DMAF_SPRITE    EQU   $0020
+DMAF_BLITTER   EQU   $0040
+DMAF_COPPER    EQU   $0080
+DMAF_RASTER    EQU   $0100
+DMAF_MASTER    EQU   $0200
+DMAF_BLITHOG   EQU   $0400
+DMAF_ALL       EQU   $01FF  ; all dma channels
+
+* read definitions for dmaconr
+* bits 0-8 correspnd to dmaconw definitions
+DMAF_BLTDONE   EQU   $4000
+DMAF_BLTNZERO  EQU   $2000
+
+DMAB_SETCLR    EQU   15
+DMAB_AUD0      EQU   0
+DMAB_AUD1      EQU   1
+DMAB_AUD2      EQU   2
+DMAB_AUD3      EQU   3
+DMAB_DISK      EQU   4
+DMAB_SPRITE    EQU   5
+DMAB_BLITTER   EQU   6
+DMAB_COPPER    EQU   7
+DMAB_RASTER    EQU   8
+DMAB_MASTER    EQU   9
+DMAB_BLITHOG   EQU   10
+DMAB_BLTDONE   EQU   14
+DMAB_BLTNZERO  EQU   13
+
+	ENDC	; HARDWARE_DMABITS_I

original/player.i

@@ -0,0 +1,101 @@
+; MySong offsets
+org_sv_num_waves_b          = $00
+org_sv_num_steps_b          = $01
+org_sv_num_steps_w          = $02
+org_sv_patterns_ptr         = $04
+org_sv_inst_patterns_table  = $08 ; 32 ($18) waves max (until $88)
+org_sv_curr_pat_pos_l       = $88 ; only byte used FIXME why is this part of MySong? Should be in Player
+org_sv_pat_pos_len_l        = $8c ; only byte used
+org_sv_pat_restart_pos_l    = $90 ; only byte used
+org_sv_pos_data_adr         = $94
+org_sv_inst_infos_ptr       = $98
+org_sv_waveinfo_ptr         = $9c ; base pointer of wave info
+org_sv_pattern_table        = $a0 ; until $49c (excl.)
+; $4d0 bytes of nothing here
+org_sv_wavegen_order_table  = $96c ; 24 bytes
+
+; ----------------------------------------
+
+; channel structure
+org_pcd_arp_notes_l         = 0
+org_pcd_arp_note_1_b        = 0
+org_pcd_arp_note_2_b        = 1
+org_pcd_arp_note_3_b        = 2
+org_pcd_last_trigger_pos_w  = 4 ; I think this makes sure that we don't retrigger the note on same pos
+org_pcd_pat_vol_b           = 6 ; Multiplied with volume of instrument.
+org_pcd_pat_portamento_speed_b = 7
+org_pcd_pat_adsr_rel_delay_b = 8 ; counts down until adsr release. Seems unused?
+org_pcd_pat_2nd_inst_num_b  = 9
+org_pcd_pat_2nd_inst_delay_b = 10 ; low byte only?
+org_pcd_pat_vol_ramp_speed_b = 11
+org_pcd_new_inst_num_b      = 12 ; load new instrument (number)
+org_pcd_wave_offset_b       = 13
+org_pcd_note_off_delay_b    = 14  ; time before note is released ($ff = disabled)
+org_pcd_note_delay_b        = 15  ; $ff = no note delay
+org_pcd_pat_portamento_dest_w = $10 ; portamento destination pitch
+org_pcd_pat_pitch_slide_w   = $12
+org_pcd_track_delay_steps_b = $14 ; $00 = no track delay, $ff = stop track delay (this is for the next channel!)
+org_pcd_track_delay_offset_b = $15 ; $ff = no track delay
+org_pcd_track_delay_vol16_b = $16
+
+org_pcd_inst_vol_w          = $18
+org_pcd_inst_num_w          = $1a ; current instrument number (lower byte used)
+org_pcd_inst_wave_num_w     = $1c ; current wave number (1 based) (lower byte used)
+org_pcd_loaded_inst_vol_w   = $1e ; low byte only
+org_pcd_inst_sel_arp_note_w = $20
+org_pcd_inst_new_step_w     = $22 ; seems to be unused
+org_pcd_inst_ping_pong_s_w  = $24 ; direction of pingpong (-1 / +1)
+org_pcd_inst_pitch_pinned_b = $26
+org_pcd_inst_vol_slide_w    = $28
+org_pcd_inst_pitch_w        = $2a
+org_pcd_inst_curr_port_pitch_w = $2c
+org_pcd_inst_note_pitch_w   = $2e
+org_pcd_inst_pitch_slide_w  = $30
+org_pcd_inst_subloop_wait_w = $32
+org_pcd_inst_loop_offset_l  = $34 ; only lower word reasonable
+org_pcd_inst_info_ptr       = $38 ; pointer to currently active instrument
+
+org_pcd_waveinfo_ptr        = $3c ; pointer to currently active waveinfo
+org_pcd_adsr_phase_l        = $40 ; 0=attack, 1=decay, 2=sustain, 3=release
+org_pcd_adsr_phase_speed_b  = $44 ;
+org_pcd_adsr_pos_w          = $46 ; $10 (release pos?)
+org_pcd_adsr_vol64_w        = $48 ; speed? ($48)+($46)
+org_pcd_adsr_attack_speed_l = $4a ; (low byte only)
+org_pcd_adsr_decay_speed_l  = $4e ; (low byte only)
+org_pcd_adsr_sustain_l      = $52 ; 15/16 (low byte only)
+org_pcd_adsr_release_l 		= $56 ; read in release (low byte only)
+org_pcd_adsr_volume_l       = $5a ; 0 for restart / $400 (word only)
+org_pcd_adsr_trigger_b      = $5e ; 1 for restart (FIXME: never read??)
+org_pcd_vibrato_pos_w       = $60 ;
+org_pcd_vibrato_depth_w     = $62 ; is a byte value
+org_pcd_vibrato_speed_w     = $64 ; is a byte value
+org_pcd_vibrato_delay_w     = $66 ; is a byte value
+
+org_pcd_inst_step_pos_b     = $68
+org_pcd_inst_speed_stop_b   = $69 ; speed byte, $ff stops processing
+org_pcd_inst_line_ticks_b   = $6a ; $00
+org_pcd_channel_num_b       = $6b
+org_pcd_track_delay_buffer  = $7c ; 16 bytes x 32 steps, until $27c
+
+org_pcd_out_ptr_l       	= $6c
+org_pcd_out_len_w       	= $70
+org_pcd_out_lof_w       	= $72
+org_pcd_out_per_w       	= $74
+org_pcd_out_vol_b       	= $76
+org_pcd_out_trg_b       	= $77
+org_pcd_out_unused_l    	= $78 ; copied for track delay, but not used?
+org_pcd_SIZEOF              = $27c
+
+; player global variables (not bound to channel)
+org_pv_pat_curr_row_b       = $9f0 ; what is this? bit 0 is tested for shuffle
+org_pv_next_pat_row_b       = $9f1
+org_pv_next_pat_pos_b       = $9f2
+org_pv_pat_speed_b          = $9f3 ; speed byte (unfiltered)
+org_pv_pat_line_ticks_b     = $9f4
+org_pv_my_song              = $9f6 ; fw_PretrackerMySong
+org_pv_pat_stopped_b        = $9fa ; 0 = stop, 1 = run
+
+org_pv_wave_sample_table    = $9fc ; 24 pointers to sample starts, until $a5c
+org_pv_sample_buffer_ptr    = $a5c ; pointer to empty sample (for idle channel)
+org_pv_osc_buffers          = $a60
+org_pv_loop_pattern_b       = $1c6c ; repeat current pattern, do not advance

original/readme.txt

@@ -0,0 +1,6 @@
+Here's the original player in binary form and resourced by hitchhikr
+(his original archive does no longer seem to be available).
+
+I added a player.i include file with the "original offsets" of the
+internal data structures, in case you want to fiddle with it.
+

src/drop_in_replacement.asm

@@ -0,0 +1,17 @@
+; vasmm68k_mot.exe -devpac -Fbin -o ..\binaries\raspberry_casket.bin -opt-allbra drop_in_replacement.asm
+
+PRETRACKER_SUPPORT_V1_5 = 0
+PRETRACKER_PARANOIA_MODE = 0
+PRETRACKER_DUBIOUS_PITCH_SHIFT_FOR_DELAYED_TRACK = 0
+PRETRACKER_KEEP_JUMP_TABLE = 1
+PRETRACKER_SONG_END_DETECTION = 0
+PRETRACKER_PROGRESS_SUPPORT = 0
+PRETRACKER_FASTER_CODE = 1
+PRETRACKER_VOLUME_TABLE = 1
+PRETRACKER_BUGFIX_CODE = 1
+PRETRACKER_DONT_TRASH_REGS = 1
+PRETRACKER_COPPER_OUTPUT = 0
+
+        opt     p+,o+
+        
+        include "raspberry_casket.asm"