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Revision as of 11:07, 31 maj 2026;
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RMT 1.x instrument format
--------------------------------
header struct
=============
offset type desc
------ ---- ----
00 BYTE header string 'RTI' ($52 $54 $49)
03 BYTE version ($00 or $01)
04 BYTE name (space-padded, terminating zero in byte 32 ASCII string)
25 BYTE length of instrument definition block
26... BYTE instrument definition block
instrument struct
=================
offset type desc
------ ---- ----
00 BYTE tlen (pointer to end of table of notes)
01 BYTE tgo (pointer to loop of table of notes)
02 BYTE elen (pointer to end of envelope)
03 BYTE ego (pointer to loop of envelope)
04 BYTE tspd (bit 0-5), tmode (bit 6), ttype (bit 7)
05 BYTE audctl
06 BYTE vslide
07 BYTE vmin(bit 4-7)
08 BYTE delay ($00 for no vibrato & no fshift)
09 BYTE vibrato (0-3)
0a BYTE fshift
0b BYTE unused
0c table of notes
? envelope
ttype
-----
0 - notes
1 - freqs
tmode
-----
0 - +
1 - +=
TABLE OF NOTES struct
=====================
BYTE note or frequence (according to the ttype)
ENVELOPE struct
===============
BYTE volume (bit 0-3 left channel) (bits 4-7 right channel
(in RMT4 it's the same as bits 0-3))
BYTE portamento (bit 0), distortion(bit 1-3),
command (bit 4-6), filter (bit 7)
BYTE XY
distortion
----------
0 - $0v
2 - $2v
4 - $4v
6 - $Cv 16-bit bass table tone
8 - $8v
A - $Av pure tone
C - $Cv bass 1 table tone
E - $Cv bass 2 table tone
command
-------
0 - play BASE_NOTE + $XY semitones
1 - play frequency $XY
2 - play BASE_NOTE + frequency $XY
3 - set BASE_NOTE += $XY semitones; play BASE_NOTE
4 - set FSHIFT += frequency $XY; play BASE_NOTE
5 - set PORTAMENTO speed $X and step $Y; play BASE_NOTE
6 - set FILTER_SHFRQ += frequency $XY; play BASE_NOTE
7 - set BASE_NOTE = $XY; play BASE_NOTE / if $XY == $80 then VOLUMEONLY mode
