Potential problems
------------------

- pattern encoding limits samples/instruments to 255
- instrument note mapping table limits samples to 255
- In s.Seq trouble in Mix Mode, safe condition: channels < 128
- In h.ISong loop pos stored as 1 byte => 0 < row <= 255
- Limit max channels to last which use an instrument, while playing on pattern
  decoding a channel behind that one may be read.

Special files
-------------

!SkipProcessStream/it   -> Cuts notes volume for a moment for check of Skip routine
Cybo-Occultation/ult    -> Arpeggio, panning, break
LoadMusic               -> MUSX file with unaligned SDAT tag
Filters                 -> Playlist of IT files with resonant filters

669.
Detune/669              -> Test "detune" effect.
Length/669              -> Test tempo.
SlideDown/669           -> Test pitch slide down "no limits" behaviour.
SlideUp/669             -> Test pitch slide up "no limits" behaviour.
Vibrato/669             -> Test vibrato effect.

AMF.
Converted S3M test files (see below).

DSym.
!Note_Volume_Slides/dsym-> Test of effects 0A, 11, 1B.
!Panning/dsym           -> Test of effect 30.
!Pitch_Slides/dsym      -> Test of effects 10, 11, 12, 20.
!Retrig/dsym            -> Test of effect 19.
!Tremolo/dsym           -> Test of effect 07.
!Tremolo0F/dsym         -> Test of effect 07.
!TremoloF0/dsym         -> Test of effect 07.
!Vibrato/dsym           -> Test of effect 04.
!Vibrato0F/dsym         -> Test of effect 04.
!VibratoF0/dsym         -> Test of effect 04.
GalaxyMedley/zip        -> Tremolo
Klisje/zip              -> Allowed effects
ManicMiner/zip          -> Instrument without note used to set volume to default
                           for that sample, freeing the effect column for another
                           effect.
DSym.MBazley/zip.
JN                      -> Handling of unknown effects
LoopLast/OneLoop        -> Handling of loops in last position
RepeatNest              -> Nested loops on the same row ("infinite loops")
TRIAL                   -> There was a bug in sample decompression
DSym.tpdemo/zip.
APPEAREN                -> Sample with both length and title length 0
SampNums                -> Sample nr change (sample without note) -> reset
Slides                  -> Pitch slides on whole note range
Tremolo                 -> Tremolo
DSym.tpdemo3/zip.
DEFLORATON              -> Invalid Set sample offset
LEKTROPHIL              -> Set sample offset with no note (has no effect)
DSym.tpdemo4/zip.
BrkInvalid              -> Invalid break, must break to 0 in next pattern
InsInvalid              -> First note without inst, plays nothing
LineJump                -> LineJump effect
PosInvalid              -> Invalid jump, should jump to 0
UnsetRep                -> Unset sample loop
VolInvalid              -> Invalid volume, should set to max volume
DSym.tpdemo5/zip.
LastPos                 -> Jump to last pos

IT.
!Arpeggio_A/it          -> Test of effect Jxy at various speeds (Amiga)
!Arpeggio_L/it          -> Test of effect Jxy at various speeds (Linear)
!Channel_Volume_Slides/it-> Test of effects Mxx and Nxy.
!Env_Carry/it        KO -> Test envelope with carry flag.
!Env_Filter/it       KO -> Test filter envelope & enable/disable envelope.
!Env_Panning/it      KO -> Test panning envelope & enable/disable envelope.
!Env_Panning2/it        -> Test panning envelope loops.
!Env_Pitch/it        KO -> Test pitch envelope & enable/disable envelope.
!Env_Volume/it          -> Test volume envelope & enable/disable envelope.
!Global_Volume_Slides/it-> Test of effects Vxx and Wxy.
!KeyOff_Inst/it         -> Test effect of KeyOff on instrument+envelopes combi
!KeyOff_Smp/it          -> Test effect of KeyOff on sample
!Note_Volume_Slides/it  -> Test of volume column, volume column effects Ax to Dx
                           and effect Dxy.
!Panbrello_New/it       -> Test of effect Yxy and S5x (new effects mode).
!Panbrello_Old/it       -> Test of effect Yxy and S5x (old effects mode).
!Panning_Slides/it      -> Test of panning in volume column
                           and effects Pxy, S8x, S91, Xxx.
!Pitch_Slides_A/it   KO -> Test of volume column effects Ex, Fx and effects
                           Exx, Fxx (Amiga).
!Pitch_Slides_L/it   KO -> Test of volume column effects Ex, Fx and effects
                           Exx, Fxx (Linear).
                           Effect EE8 followed by volume effects E0 should lead to
                           massive slides by 0xE8, while we do it by 0x08.
!Retrig.it              -> Test of effect Qxy.
!SwapInst/it            -> Test of instrument "swapping".
!SwapInst2_(swing)/it   -> Test of instrument "swapping" & inst swing.
!TremoloNew/it          -> Test of effect Rxy and S4x (new effects mode).
!TremoloOld/it          -> Test of effect Rxy and S4x (old effects mode).
!TremorNew/it           -> Test of effect Ixy (new effects mode).
!TremorOld/it           -> Test of effect Ixy (old effects mode).
!VibratoType_LNew/it    -> Test of effect S3x (Linear, new effects mode).
!VibratoType_LOld/it    -> Test of effect S3x (Linear, old effects mode).
!Vibrato_ANew/it        -> Test of effects Hxy, Uxy (Amiga, new effects mode).
!Vibrato_AOld/it        -> Test of effects Hxy, Uxy (Amiga, old effects mode).
!Vibrato_LNew/it        -> Test of effects Hxy, Uxy (Linear, new effects mode).
!Vibrato_LOld/it        -> Test of effects Hxy, Uxy (Linear, old effects mode).
!VoidSamples/it         -> Test swapping with empty instruments.
01.it                   -> Combi Arpeggio + pitch slide
02.it                   -> Arpeggio 00 without previous val = ignore
03.it                   -> Linked EF/G, first F00 active
                           Note will go up, down and up again
04.it                   -> Unlinked EF/G, first F00 ignored till songs loops
                           Note will go up, down and stay down
05.it                   -> Linked EF/G, combi GFF with F00, must resolve as FFF
06.it                KO -> Combi effect EF1 + E0 in volume column
07.it                   -> Note cut + sample nr
08.it                KO -> Delays (> speed) + sample nr => sample used in next row 
09.it                   -> No note + sample => new note with last note nr
10.it                   -> Multiple loops
11.it                   -> Infinite loop
12.it                   -> Tremor in ch 1 and equiv with volume commands in ch 2
13.it                   -> Tremor with old effects
14.it                   -> Instrument change must not affect ping-pong loop
15.it                   -> Retrigs in ch 1 and equiv with new notes in ch 2
16.it                   -> Global volume and slides
17.it                   -> Repeats and delays
                           Only first repeat in row is used.
                     KO    Delay is triggered in each repetition of a row
18.it                   -> Sample nr trigger a note except if preceded
                           by a cut (^^^ in IT)
19.it                   -> Random vibrato
20.it                   -> Panning and swing
21.it                   -> No limits to pitch slides
22.it                   -> SC0 and SD0 behave as SC1 and SD1
23.it                KO -> Portamento with no note
                           When target reached, target is reset and Gxx is inactive
24.it                   -> Envelope loops includes end points
25.it                   -> Portamento and pitch slides
Abstain like me?.it     -> Very audible effect of carry envolope flag
Make it simple.it       -> Dummy patterns, drum beat for whole track in 1 note
                           (looped volume envelope, "continue" NNA and fadeout=0)
NowTune.it              -> Notes beyond B-9 after sample frequency translation

MDL.
!Env_Panning/mdl        -> Test of panning envelopes loops.
!Env_Pitch/mdl          -> Test of pitch envelopes loops.
!Env_Volume/mdl         -> Test of volume envelopes loops.
!Global_Volume/mdl      -> Test of effects Cxx, EAx, EBx
!KeyOff/mdl             -> Test of keyoff with fadeout and envelopes
!Note_Volume_Slides/mdl -> Test of effects Gxx, GEx, GFx, Hxx, HEx, HFx
!Panning/mdl            -> Test of effects 8xx, E1x, E2x
!Pitch_Slides/mdl       -> Test of effects 1xx, 1Ex, 1Fx, 2xx, 2Ex, 2Fx
!Retrig/mdl             -> Test of effect E9x
!Retrig_new/mdl         -> Test of effect Ixy
!SmpRate/mdl            -> Test of how sample frequency affects pitch slides
!SwapInst/mdl        KO -> Test of instrument "swapping"
!Tremolo/mdl         ?? -> Test of effect Jxx
!Tremor/mdl             -> Test of effect Kxx
!Vibrato/mdl         ?? -> Test of effect 4xx
!VoidSamples/mdl        -> Test of empty instrument "swapping"

MOD.
!Note_Volume_Slides/mod -> Test of effects Axy, Cxx, EAx, EBx
!Panning/mod            -> Test of effects 8xx, E8x
!Pitch_Slides/mod       -> Test of effects 1xx, 2xx, E1x, E2x
!Retrig/mod             -> Test of effect E9x
!Tremolo/mod            -> Test of effect 7xy
!Tremolo0F/mod          -> Test of effect 70F
!TremoloF0/mod          -> Test of effect 7F0
!Vibrato/mod            -> Test of effect 4xy
!Vibrato0F/mod          -> Test of effect 40F
!VibratoF0/mod          -> Test of effect 4F0
(Oil Imperium) action1/stk -> ? Ultimate soundtracker ?
1993/mod                -> "no sample data swap" behaviour in pattern 03 row 12???
1st try/mod             -> 8 channels FA0x
Aces of Spades/mod      -> 16 channels xxCN
Acidbat2/mod            -> 15 instruments and default tempo <> 120
BeachParty/mod          -> Note Retrig
bio-longpatts/stk       -> 8 channels xCHN, tempo, speed, repeat, jump
bio-twopatts/stk        -> 8 channels FLTx (2x 4CH patterns)
CoffeeBlues2&3/mod      -> Breaks and jumps on the same line, note delay
Creation2/mod           ->
Directory               -> older with 15 instruments MODs
Era/mod                 -> 8 channels TXPx
Kingdom/mod             -> 4 channels NSMS
Klisje paa Klisje/mod   -> F20 (VBLANK mode? seems like a converted 15 inst.)
Mc Hammer/mod           -> Invlid Cxx in Pattern 5, must be clipped to max volume
Messy Hair/mod          -> 5 octaves
Pitty in Concert/mod    -> Seq 28, Pt 33, requires sample swapping option
Skylantern/mod          -> Multiple repeats on same row
Space Debris/mod        -> Portamento, set sample offset
Squashed/zip            -> Unsupported squashed MOD
subbass(mega-rave)/mod  -> 
The Shades/mod          -> Good interpolation check
The War/mod             -> Repeat at end (affects volume slides)
Tocatta/mod             -> Break
tu_rmsh/mod             -> Jump & Breaks used to play patterns backwards
Vortex/mod              -> Jump & Breaks used to play patterns backwards
Warp1/mod               -> Sample nr without note -> reset
Wax Unlimited 93-94/mod -> 6CHN, tempo, arpeggio, tremolo
                           Repeat at very start (musn't restart note)
x-dream/mod             -> 8 channels CD81

MT2.
J.track03/mt2           -> Gapper effet
Virtual Man.into the Darkness/mt2 -> Gapper effet

PTM.
!Global_Volume/ptm      -> Test of effects Gxx
!Note_Volume_Slides/ptm -> Test of effects Cxx, A0x, Ax0, AFx, AxF, volume column
!Panning/ptm            -> Test of effects E8x
!Pitch_Slides/ptm       -> Test of effects 1xx, 1Ex, 1Fx, 2xx, 2Ex, 2Fx
!Retrig/ptm          KO -> Test of effect E9x
!Retrig_new/ptm      KO -> Test of effect Hxy
!SampleOffset/ptm       -> Test of effect 9xx on 16-bit sample
!SlowSlide_Retrig/ptm KO-> Test of effect Lxy, Mxy
!VoidSamples/ptm        -> Test of instrument "swapping"

S3M.
!Global_Volume/s3m      -> Test of effects Vxx
!Note_Volume_FSlides/s3m-> Test of volume column and effect Dxy. Fast slides on
!Note_Volume_Slides/s3m -> Test of volume column and effect Dxy. Fast slides off
!Panning/s3m            -> Test of panning in volume column
                           and effects Pxy, S8x, X81, Xxx
!Pitch_Slides/s3m       -> Test of effects Exx, Fxx
!Retrig/s3m             -> Test of effect Qxy
!SwapInst/s3m           -> Test of instrument "swapping"
!Tremolo/s3m            -> Test of effect Rxy
!Tremor/s3m             -> Test of effect Ixy
!Vibrato/s3m            -> Test of effects Hxy, Uxy
!VoidSamples/s3m        -> Test of empty instrument "swapping"
Catch that Goblin!!/s3m -> Loop, break, retrig, cut, vibrato, tremor, note delay
jp3/zip                 -> Influence of sample frequency on pitch slides amplitude
Panic/s3m               -> Vibrato, retrig, arpeggio, panning, set sample offset
                         , Slide to high pitch -> stop note

XM.
!Env_Panning/xm      KO -> Test panning envelopes
!Env_Volume/xm          -> Test volume envelopes
!Global_Volume_Slides/xm-> Test of effects Gxx and Hxy
!KeyOff_Inst/xm         -> Test of KeyOff for different instruments+envelopes
!Note_Volume_Slides/xm  -> Test of volume column, volume column effects
                           -x, +x, vx, ^x and effects Axy, EAx, EBx
!Panning_Slides/xm   KO -> Test of volume column effects
                           Px, <x, >x and effects 8xx, Pxy
!Pitch_Slides_A/xm      -> Test of effects 1xx, 2xx, E1x, E2x, X1x, X2x
                           Amiga periods
!Pitch_Slides_L/xm      -> Test of effects 1xx, 2xx, E1x, E2x, X1x, X2x
                           Linear semitones
!Retrig/xm              -> Test of effects E9x, Rxy
!SmpRate/xm             -> Test of effects of reltone on pitch slides
!SwapInst/xm            -> Test of instrument "swapping"
!Tremolo/xm             -> Test of effect 7xy
!Tremor/xm              -> Test of effect Txy
!Vibrato_A/xm           -> Test of effect 4xy and volume effects Vx, Sx
                           Amiga periods
!Vibrato_L/xm           -> Test of effect 4xy and volume effects Vx, Sx
                           Linear semitones
!VoidSamples/xm         -> Test of empty instrument "swapping"
1/xm                    -> Sample set offset, repeat, panning slide
C-vensap/zip            -> Glb Volume Set, OffXM
indi5/xm                ->
Rompelo/xm              -> Testcase for volume ramping
Trans_Atlantic/xm       -> Old v1.02 format
warsaw/xm            KO -> XM bug loop in last row jumps to row 3 of next pattern
                           meaning that the jump is skipped and the song played.
                           We just move to start next row and trigger the jump
                           to the end of the song.
x-girlfriend/xm         -> XM with comments

Astray/s3m -> vibrato, portamento
Northern Sky/it -> tremor
Sq_cheez/xm  -> sample vibrato
yb-kfc/it -> pitch pan sep, pan swing
K_Stray/it -> J00 (arpeggio)
torturer/it -> surround channel
Cps-Burn/it -> SA effects
Story~1/xm, Arnomania/xm -> Lxx set envelope pos
xmas & funky99 -> sin waves for testing
CJ.Obscure/it -> Volume envelope on
Martian Love Song/it -> instrument swap (pattern 45, channel 8)

Fantazy.hellsector-3/fc (/4/fc /5/fc) -> Slide (Freq, Vol)
