Optimized ping pong some more.

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2022 Chris 'platon42' Hodges <chrisly@platon42.de>
+Copyright (c) 2022-2023 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

@@ -1,7 +1,7 @@
 # Raspberry Casket
 A fast and small open source Pretracker replayer
 
-## Raspberry Casket Player V1.1 (28-Dec-2022)
+## Raspberry Casket Player V2.x (24-Aug-2023)
 
 Provided by Chris 'platon42' Hodges <chrisly@platon42.de>
 
@@ -15,26 +15,43 @@ 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.
+Bugs from the original replayer were fixed.
 
 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.
+Note that this player can be also used for the playback of
+Pretracker 1.5 tunes, given you don't use sfx or sub-songs.
 
-Also: Open source. It's 2022, keeping the code closed is just not
+Also: Open source. It's 2023, 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.
+This player is still being optimized and worked on since its
+first release in late 2022.
+
+Productions that I know have been using Raspberry Casket so far:
+
+- [Smooth Flowing/Dekadence](https://www.pouet.net/prod.php?which=94347)
+- [Cracking Posadas/Software Failure](https://www.pouet.net/prod.php?which=94570)
 
 ### 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).
+The first versions of the replayer had been verified against 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,
+During the process this identical state and identical samples promise
+had to be dropped due to bugs in the original player and optimizations.
+This is especially the case for the track delay feature of Pretracker
+that could in some cases cause odd behaviour and unwanted muting that
+has been fixed in Raspberry Casket. So the verification is now heavily
+reduced to about 20 songs that still are identical.
+
+I do, however, now also have an emulated Paula output verification that
+compares the generated sound between the original code and Raspberry Casket.
+Divergences are manually checked from time to time.
+
+If you find some problems,
 please let me know under chrisly@platon42.de. Thank you.
 
 ### Usage
@@ -72,19 +89,19 @@ The source needs two common include files to compile (`custom.i` and
 
    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).
+   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.
+less than 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
-6216 bytes and goes down to ~4348 bytes (in isolation).
+5716 bytes and shrinkles down to ~4071 bytes (in isolation).
 
 So this means that the optimization is not just "on the outside".
 
@@ -93,8 +110,20 @@ the remaining code for playback.
 
 ### Timing
 
-Sample generation is a bit faster (I guess around 10-15%),
-but most of the time is spent on `muls` operations, so this is the limiting factor.
+#### Sample precalculation
+
+Sample generation is faster than the original 1.0 player and also
+faster than the 1.5 player, which got a slightly better performance
+than the 1.0 one (compiler change?).
+
+According to my measurements on my set of Pretracker tunes,
+Raspberry Casket needs between 10% to 20% less instructions.
+Of these instructions, about 5% are `muls` operations and the new
+player is only able to shave off between 3% and 8% percent of those,
+so this is probably the limiting factor.
+
+#### Playback
+
 Raspberry Casket is about twice as fast as the old replayer for playback.
 
 Unfortunately, the replayer is still pretty slow and has high
@@ -108,20 +137,56 @@ about 34 on average!).
 Watch out for *Presto*, the [LightSpeedPlayer](https://github.com/arnaud-carre/LSPlayer) variant that should
 solve this problem.
 
+### Secrets
+
+- Pink never actually documented how the 0xy command works (2nd instrument, not an ARP!).
+  It will play the instrument y for x+1 ticks before going to the actual instrument you wanted to trigger in the first place.
+  This works well, e.g. for bassdrums and other short percussion samples. Note that because y is a 4 bit nibble, you can only
+  specify the instruments $1-$f this way and not $10-$1f.
+
 ### Known issues
 
+- Songs saved with earlier versions of Pretracker than 1.0 (internal version lower than $1b) have stored the ADSR values differently in the file.
+  There is no provision for fixing these values neither in the original player nor in Raspberry Casket. Loading the file in the tracker and saving
+  it again will cure this. This is more of a hypothetical problem as you are unlikely to use a Pretracker V0.9 beta version, but it took me quite a
+  while why Pink's "On and On" has a broken first wave sample in all the replayers but not on the tracker itself. This affects these tunes:
+  Attack and Release, On and On, Rewind, Cold and Tired, PreFix all by Pink and Cracksteady by Tecon.
 - Behaviour for undefined volume slides with both up- and down nibble specified is different (e.g. A9A, hi Rapture!). Don't do that.
 - Don't use loops with odd lengths and offsets (even if Pretracker allows this when dragging the loop points).
 - Don't stop the music with F00 and use a note delay (EDx) in the same line.
 - Don't try to play music with no waves, instruments or patterns.
-- Pattern breaks with target row >= $7f will be ignored.
+- The original player had the internal state machine running for wave 1 even if no note had been triggered yet on the channel.
+  This could cause the first instrument using a 4xx command (trigger wave without sync) in the instrument pattern to start at
+  a more or less random first loop offset instead of from the beginning. This is fixed in Raspberry Casket.
 - Shinobi seemed to have used an early beta version of Pretracker where it was possible to specify a Subloop Wait of 0. That's illegal and unsupported.
+- Pattern breaks with target row >= $7f will be ignored.
 - Pattern break (Dxx) + Song pos (Bxx) on the same line does not work in original Pretracker & Player: New Dxx position is ignored. 
   There is code to enable it in the player, so you could in theory make backwards running tracks like in Protracker. 
   But this doesn't make sense as long as the tracker itself does not support it.
+- Setting the same track delay multiple times will no longer mute the delayed channel and the new volume will take effect immediately.
+- Clearing the track delay (multiple times) will no longer mute the delayed channel nor cause a delay of one tick to the note played in the no-longer delayed channel.
 
 ## Changelog
 
+### V2.x (unreleased)
+- Split wave generation out of main file, reorganised content into header files.
+- Optimized some more code paths for Raspberry Casket replayer.
+- In the wave generator optimized away a table (32 words), replacement code is even smaller!
+- Replaced the period table by byte-deltas, saved 36 bytes and compression is even better!
+- Optimized some code paths for octave selection.
+- Removed two 25 bytes tables each, saving another 42 bytes.
+- Completely reworked track delay handling, fixed oddities and improved output quality.
+- This removes a big source of cpu jitter when track delay is enabled (no longer clearing the track delay buffer).
+- This also fixes usages of illegal period 0 in the lead-in that could cause the replay to miss the first trigger.
+- Moved pattern table init from PlayerInit to SongInit, optimized SongInit a bit.
+- Wave order table filling moved and optimized in SongInit.
+- Bugfix: Songend detection for back-jumps was broken since at least V1.1.
+- Optimized some more wave selection code.
+- Nosync/sync wave selection optimized.
+- Optimized wave generation a lot (esp. noise generator).
+- Added Presto player draft.
+- Drop-in replacement code size: 5716 bytes.
+
 ### V1.x (unreleased)
 - Fixed a bug regarding the copper output mode with looping waves having a loop-offset.
 - Fixed wrong register use on triggering waves regarding the loop offset.
@@ -144,4 +209,4 @@ solve this problem.
 ### V1.0 (26-Dec-22)
  
 - Initial release.
-- Drop-in replacement code size: 6446 bytes.
+- Drop-in replacement code size: 6446 bytes.

binaries/readme.txt

@@ -2,4 +2,4 @@ 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 (you need only about 2 + 12 KB).
 
-It has been assembled from src/drop_in_replacement.asm (version V1.1).
+It has been assembled from src/drop_in_replacement.asm (version V2.0).

src/drop_in_replacement.asm

@@ -1,4 +1,4 @@
-; vasmm68k_mot.exe -devpac -Fbin -o ..\binaries\raspberry_casket.bin -opt-allbra drop_in_replacement.asm
+; vasmm68k_mot.exe -I..\includes -devpac -Fbin -o ..\binaries\raspberry_casket.bin -opt-allbra drop_in_replacement.asm
 
 PRETRACKER_SUPPORT_V1_5 = 0
 PRETRACKER_PARANOIA_MODE = 0

src/raspberry_casket.i

@@ -0,0 +1,342 @@
+; Pretracker song format description:
+;
+; $0000  4: PRT<version> ($19/$1a (V0.x), $1b (V1.0), $1e (V1.5))
+; $0004  4: File offset to position data (POSD)
+; $0008  4: File offset to pattern data (PATT)
+; $000C  4: File offset to instruments (INST)
+; $0010  4: File offset to waves (WAVE)
+; $0014 20: Songname
+; $0028 20: Author
+; $003C  1: Restart position for song (<=V1.0)
+; $003D  1: Number of patterns (<=V1.0)
+; $003E  1: Songlength in patterns (<=V1.0)
+; $003F  1: Number of steps per pattern (<=V1.0)
+; $0040  1: Number of instruments (<=V1.0), $40 for V1.5
+; $0041  1: Number of waves
+; $0042 24: Wave generation ordering (>=V1.0)
+; $005a  1: Number of subsongs (>=V1.5)
+; [...]
+; Position data (POSD):
+; - Per subsong (>=V1.5)
+;   - 1: Restart pos
+;   - 1: #patterns
+;   - 1: #numsteps
+;   - 1: songlength
+;   - 4: relative pattern offset in pattern data
+; - Positions x 4 x [Pattern number (byte), pitch shift (signed byte)]
+;
+; Pattern data (PATT):
+; Each pattern line consists of three bytes:
+;   - 1 Bit : Bit 4 of Inst Number
+;   - 1 Bit : ARP instead of effect
+;   - 6 Bits: Pitch ($01 is C-0, $3d is NOTE OFF)
+;
+;   - 4 Bits: Bit 0-3 of Inst Number
+;   - 4 Bits: Effect command
+;   - 8 Bits: Effect data
+; - Patterns x steps x 3 bytes
+;
+; Unknown data after pattern data: (12 10 00 00 00 00)
+;
+; Instrument definitions (INST):
+; - 32 (!) x Null terminated string (or 23 chars max) (for V1.5 this is 64 strings)
+; - For each instrument: Instrument Info (ININ)
+;   - $00  1: Vibrato Delay
+;   - $01  1: Vibrato Depth
+;   - $02  1: Vibrato Speed (-1)
+;   - $03  1: ADSR Attack
+;   - $04  1: ADSR Decay
+;   - $05  1: ADSR Sustain
+;   - $06  1: ADSR Release
+;   - $07  1: Number of Inst Pattern steps
+;
+; - For each instrument:
+;   - 1 Byte: number of steps
+;   - 3 Bytes x number of steps: Inst Pattern (IPTT)
+;
+; Inst pattern data (IPTT):
+; Each pattern line consists of three bytes:
+;   - 1 Bit  : Next note stitched to this one
+;   - 1 Bit  : Fixed Pitch Note
+;   - 6 Bits : Pitch ($01 is C-0)
+;   - 4 Bits : unused?
+;   - 12 Bits: Effect
+;
+; Wave definitions (WAVE):
+; - 24 (!) x Null terminated string (or 23 chars max)
+; - Optional padding to even address, if necessary
+; - For each wave:
+;   - 42 Bytes: Wave info structure (see definition below)
+
+; ----------------------------------------
+; Some constants for clarity
+
+MAX_VOLUME      = $40
+MAX_SPEED       = $2f
+MAX_WAVES       = 24
+MAX_INSTRUMENTS = 32
+MAX_TRACK_DELAY = 32
+NOTE_OFF_PITCH  = $3d
+NOTES_IN_OCTAVE = 12
+NUM_CHANNELS    = 4     ; yes, you can reduce the number of channels if you want
+
+; ----------------------------------------
+; Pretracker file structures
+
+; Pattern data (PATT and IPTT)
+pdb_pitch_ctrl      = 0
+pdb_inst_effect     = 1 ; for normal pattern data
+pdb_effect_cmd      = 1 ; for inst pattern
+pdb_effect_data     = 2
+
+; Pattern pos data (POSD)
+ppd_pat_num         = 0
+ppd_pat_shift       = 1
+
+; Instrument Info (ININ)
+ii_vibrato_delay    = 0
+ii_vibrato_depth    = 1
+ii_vibrato_speed    = 2
+ii_adsr_attack      = 3
+ii_adsr_decay       = 4
+ii_adsr_sustain     = 5
+ii_adsr_release     = 6
+ii_pattern_steps    = 7
+ii_SIZEOF           = 8
+
+; Wave Info (WAVE)
+wi_loop_start_w    = $00
+wi_loop_end_w      = $02
+wi_subloop_len_w   = $04
+wi_allow_9xx_b     = $06 ; 0x00 / 0x01
+wi_subloop_wait_b  = $07
+wi_subloop_step_w  = $08
+wi_chipram_w       = $0a
+wi_loop_offset_w   = $0c
+wi_chord_note1_b   = $0e
+wi_chord_note2_b   = $0f
+wi_chord_note3_b   = $10
+wi_chord_shift_b   = $11
+wi_osc_unknown_b   = $12 ; always $00? (unused in code?)
+wi_osc_phase_spd_b = $13
+wi_flags_b         = $14 ; bit 0/1: osc type, bit 2: needs extra octaves, bit 3: boost, bit 4: pitch linear, bit 5: vol fast
+wi_osc_phase_min_b = $15
+wi_osc_phase_max_b = $16
+wi_osc_basenote_b  = $17
+wi_osc_gain_b      = $18
+wi_sam_len_b       = $19 ; in multiples of 128, zero-based (0 == 128)
+wi_mix_wave_b      = $1a
+wi_vol_attack_b    = $1b
+wi_vol_delay_b     = $1c
+wi_vol_decay_b     = $1d
+wi_vol_sustain_b   = $1e
+wi_flt_type_b      = $1f ; 1=lowpass, 2=highpass, 3=bandpass, 4=notch
+wi_flt_resonance_b = $20
+wi_pitch_ramp_b    = $21
+wi_flt_start_b     = $22
+wi_flt_min_b       = $23
+wi_flt_max_b       = $24
+wi_flt_speed_b     = $25
+wi_mod_params_l    = $26
+wi_mod_wetness_b   = $26
+wi_mod_length_b    = $27
+wi_mod_predelay_b  = $28
+wi_mod_density_b   = $29 ; (1-7), unisono (bits 3/4) and post bit 5
+wi_SIZEOF          = $2a
+
+; ----------------------------------------
+; Unpacked Instrument Info (addition to player for faster processing)
+                    rsreset
+uii_vibrato_delay   rs.w    1
+uii_vibrato_depth   rs.w    1
+uii_vibrato_speed   rs.w    1
+uii_adsr_release    rs.b    1
+                    rs.b    1 ; dummy
+uii_adsr_attack     rs.w    1
+uii_adsr_decay      rs.w    1
+uii_adsr_sustain    rs.w    1
+uii_pattern_steps   rs.b    1
+                    rs.b    1 ; padding
+uii_SIZEOF          rs.b    0
+
+; ----------------------------------------
+; MySong offsets
+                        rsreset
+sv_waveinfo_table       rs.l    MAX_WAVES ; 24 pointers to wave infos to avoid mulu
+sv_inst_patterns_table  rs.l    MAX_INSTRUMENTS ; 32 pointers to pattern data
+                        ; --- 127 byte displacement limit ---
+sv_wavelength_table     rs.l    MAX_WAVES ; 24 longwords to sample lengths (standard octave) (NEW)
+sv_wavetotal_table      rs.l    MAX_WAVES ; 24 longwords to sample lengths for all octaves (NEW)
+sv_wavegen_order_table  rs.b    MAX_WAVES ; 24 bytes
+sv_num_waves_b          rs.b    1
+sv_num_steps_b          rs.b    1
+sv_pat_pos_len_w        rs.w    1 ; only byte used
+sv_pat_restart_pos_w    rs.w    1 ; only byte used
+sv_pos_data_adr         rs.l    1
+sv_waveinfo_ptr         rs.l    1 ; base pointer of wave info
+sv_inst_infos_table     rs.b    MAX_INSTRUMENTS*uii_SIZEOF
+sv_pattern_table        rs.l    256
+sv_SIZEOF               rs.b    0
+
+; ----------------------------------------
+; channel output data (part of pcd structure below) -- FIXED ORDER!
+                rsreset
+ocd_sam_ptr     rs.l    1   ; 0
+ocd_length      rs.w    1   ; 4
+ocd_loop_offset rs.w    1   ; 6
+ocd_period      rs.w    1   ; 8
+ocd_volume      rs.b    1   ; 10
+ocd_trigger     rs.b    1   ; 11 needs to be after volume
+ocd_unused      rs.l    1   ; 12 unused, but makes the structure an even 16 bytes
+ocd_SIZEOF      rs.b    0
+
+; channel structure (part of pv structure)
+                            rsreset
+; DO NOT CHANGE ORDER -- OPTIMIZED CLEARING
+pcd_pat_portamento_dest_w   rs.w    1 ; portamento destination pitch
+pcd_pat_pitch_slide_w       rs.w    1
+
+pcd_pat_vol_ramp_speed_b    rs.b    1
+pcd_pat_2nd_inst_num4_b     rs.b    1
+pcd_pat_2nd_inst_delay_b    rs.b    1
+pcd_wave_offset_b           rs.b    1
+
+pcd_inst_pitch_slide_w      rs.w    1
+pcd_inst_sel_arp_note_w     rs.w    1
+
+pcd_inst_note_pitch_w       rs.w    1
+pcd_inst_curr_port_pitch_w  rs.w    1
+
+pcd_inst_line_ticks_b       rs.b    1
+pcd_inst_pitch_pinned_b     rs.b    1
+pcd_inst_vol_slide_b        rs.b    1
+pcd_inst_step_pos_b         rs.b    1
+
+pcd_inst_wave_num4_w        rs.w    1 ; current wave number (1 based, times 4) (lower byte used)
+
+pcd_track_delay_offset_b    rs.b    1 ; $ff = no track delay
+pcd_inst_speed_stop_b       rs.b    1 ; speed byte, $ff stops processing
+pcd_inst_pitch_w            rs.w    1
+
+pcd_inst_vol_w              rs.w    1
+pcd_loaded_inst_vol_b       rs.b    1
+pcd_pat_vol_b               rs.b    1 ; Multiplied with volume of instrument.
+; DO NOT CHANGE ORDER -- OPTIMIZED CLEARING END
+
+pcd_arp_notes_l             rs.b    0
+pcd_arp_note_1_b            rs.b    1
+pcd_arp_note_2_b            rs.b    1
+pcd_arp_note_3_b            rs.b    1
+                            rs.b    1 ; gets cleared
+
+pcd_last_trigger_length_w   rs.w    1 ; I think this makes sure that we trigger the note if the length changes
+
+pcd_pat_portamento_speed_b  rs.b    1
+pcd_pat_adsr_rel_delay_b    rs.b    1 ; counts down until adsr release. Seems unused?
+pcd_note_off_delay_b        rs.b    1 ; time before note is released ($ff = disabled)
+pcd_inst_pattern_steps_b    rs.b    1 ; number of steps in instrument pattern
+
+pcd_note_delay_b            rs.b    1 ; $ff = no note delay
+pcd_track_delay_steps_b     rs.b    1 ; $00 = no track delay, $xx = track delay xx (this is for the next channel!)
+pcd_track_delay_vol16_b     rs.b    1 ; needs to be at even address (using word access to shift << 8)
+pcd_track_init_delay_b      rs.b    1 ; number of frames to ignore the delay
+
+pcd_inst_num4_w             rs.w    1 ; current instrument number * 4
+pcd_inst_subloop_wait_w     rs.w    1
+pcd_inst_loop_offset_w      rs.w    1
+pcd_inst_info_ptr           rs.l    1 ; pointer to currently active instrument
+
+pcd_waveinfo_ptr            rs.l    1 ; pointer to currently active waveinfo
+pcd_channel_mask_b          rs.b    1
+pcd_channel_num_b           rs.b    1
+pcd_adsr_phase_w            rs.w    1 ; 0=attack, 1=decay, 2=sustain, 3=release ! do not change order
+pcd_adsr_volume_w           rs.w    1 ; 0 for restart / $400 (word only) ! do not change order
+pcd_adsr_phase_speed_b      rs.b    1
+pcd_inst_ping_pong_dir_b    rs.b    1 ; direction of ping-pong (-1 == $00 / +1 = $ff)
+pcd_adsr_pos_w              rs.w    1 ; pos in adsr curve
+pcd_adsr_vol64_w            rs.w    1 ; some adsr volume
+
+pcd_new_inst_num_b          rs.b    1 ; load new instrument (number) ! do not change order
+                            rs.b    1 ; gets cleared
+pcd_vibrato_pos_w           rs.w    1 ;
+pcd_vibrato_delay_w         rs.w    1 ; is a byte value ! do not change order
+pcd_vibrato_depth_w         rs.w    1 ; is a byte value ! do not change order
+pcd_vibrato_speed_w         rs.w    1 ; is a byte value ! do not change order
+pcd_adsr_release_b          rs.b    1 ; is a byte value ! do not change order
+                            rs.b    1 ; padding will be overwritten!
+
+pcd_out_base                rs.b    ocd_SIZEOF
+pcd_track_delay_buffer      rs.b    MAX_TRACK_DELAY*ocd_SIZEOF
+pcd_SIZEOF                  rs.b    0
+
+pcd_out_ptr_l       = pcd_out_base+ocd_sam_ptr
+pcd_out_len_w       = pcd_out_base+ocd_length
+pcd_out_lof_w       = pcd_out_base+ocd_loop_offset
+pcd_out_per_w       = pcd_out_base+ocd_period
+pcd_out_vol_b       = pcd_out_base+ocd_volume
+pcd_out_trg_b       = pcd_out_base+ocd_trigger
+pcd_out_unused_l    = pcd_out_base+ocd_unused          ; copied for track delay, but not used?
+
+                rsreset
+owb_saw_waves   rs.b    128
+owb_sqr_waves   rs.b    128
+owb_tri_waves   rs.b    128
+owb_SIZEOF      rs.b    0
+
+; ----------------------------------------
+; MyPlayer global variables (not bound to channel)
+                        rsreset
+; DO NOT CHANGE ORDER -- OPTIMIZED INIT
+pv_pat_curr_row_b       rs.b    1 ; current step
+pv_next_pat_row_b       rs.b    1
+pv_next_pat_pos_b       rs.b    1
+pv_pat_speed_even_b     rs.b    1 ; even shuffle speed
+
+pv_pat_speed_odd_b      rs.b    1 ; odd shuffle speed
+pv_pat_line_ticks_b     rs.b    1
+pv_pat_stopped_b        rs.b    1 ; 0 = stop, $ff = run
+pv_songend_detected_b   rs.b    1
+; DO NOT CHANGE ORDER -- OPTIMIZED INIT END
+
+pv_curr_pat_pos_w       rs.w    1 ; only byte used
+pv_loop_pattern_b       rs.b    1 ; repeat current pattern, do not advance
+                        rs.b    1 ; padding
+
+pv_trigger_mask_w       rs.w    1
+
+pv_my_song              rs.l    1
+pv_copperlist_ptr       rs.l    1
+pv_wave_sample_table    rs.l    MAX_WAVES ; 24 pointers to sample starts
+pv_period_table         rs.w    16*NOTES_IN_OCTAVE*3
+                        ; --- 127 byte displacement limit ---
+pv_sample_buffer_ptr    rs.l    1 ; pointer to start of sample buffer
+pv_stop_len_lof         rs.l    1 ; $0002 / $0000
+pv_stop_per_vol_trg     rs.l    1 ; $007b / $00 / $00
+pv_channeldata          rs.b    NUM_CHANNELS*pcd_SIZEOF
+
+                        IFNE    PRETRACKER_VOLUME_TABLE
+pv_osc_buffers          rs.b    0 ; reuse space of volume_table, which is bigger than NOTES_IN_OCTAVE*owb_SIZEOF
+pv_volume_table         rs.b    (MAX_VOLUME+1)*MAX_VOLUME*2
+                        ELSE
+pv_osc_buffers          rs.b    NOTES_IN_OCTAVE*owb_SIZEOF
+                        ENDC
+
+pv_precalc_sample_size  rs.l    1
+pv_precalc_progress_ptr rs.l    1
+pv_wg_wave_counter_w    rs.w    1
+                        IFNE    PRETRACKER_PARANOIA_MODE    ; same wave for mixing cannot be selected in Pretracker
+pv_wg_curr_wave_num_b   rs.b    1
+                        rs.b    1
+                        ENDC
+pv_wg_curr_sample_ptr   rs.l    1
+pv_wg_curr_samend_ptr   rs.l    1
+pv_wg_curr_sample_len_l rs.w    1
+pv_wg_curr_sample_len_w rs.w    1
+pv_wg_chord_note_num_b  rs.b    1 ; don't change order
+pv_wg_unisono_run_b     rs.b    1 ; don't change order
+pv_wg_chord_flag_w      rs.w    1
+pv_wg_chord_pitches     rs.l    1
+pv_wg_osc_speed_l       rs.l    1
+pv_wg_flt_taps          rs.w    4
+pv_SIZEOF               rs.b    0
+