Hmmm. This is an interesting finding indeed.
Meanwhile Alone Coder was so kind to make a translation of ProTracker instruction (yay!)
___________ZX_PRO_TRACKER_MANUAL__________________
Characteristics:
√ Tempo: 1-63
√ Positions: 256
√ Patterns: 48
√ Pattern length: 1-64
√ Ornaments: 15
√ Samples: 31
√ Player size: #c00 (PT Util: #900, sources: from #632)
√ Sample length: 64
√ Ornament length: 64
√ TurboSound (2AY) mode (7MHz CPU or Pentagon w/o indicators)
New options above v2.x:
√ Volume (global gain)
√ Write data (auto-fill input note parameters with former)
√ Scroll step (scroll down after inputting note)
√ Edit melody (roll between patterns by positions order)
√ Set up (set colors, sound etc.)
√ Positions list (order of patterns playing)
√ Pattern length (set specified pattern length for all patterns
by one click)
√ Clear sample, ornament
√ Copy sample, ornament
√ Volume transposition
√ Copy 3 channels at once (click "Channel")
PT3.x can load Pro Tracker 2.x, Sound Tracker, Sound Tracker Pro
modules.
Frequences cumulation, volume increase/decrease, envelope mask
are in Edit smp.
Use -96 displacement in ornament for fix every note to C-1.
You haven't to set F before ornament #.
ssQ/ssW - line delete/insert commands (available anywhere).
Arrow control: Q,CS,O,P,Space (or Kempston Mouse)
Disk/compilation errors are shown on border.
Since v3.697 memory isn't being cleared before loading module.
Loader:
Setups are in basic block:
5d3b, 5d3c = colours;
5d3d: bit0-2 = border;
bit4 = "play on";
bit5 = "sound";
bit6 = "print points";
bit7 = "kempston joystick";
5e16: frequency table.
Press CS to disable indicators if your computer is slow.
Hot keys:
W - Edit melody
Ext - Edit pattern
Enter - Play
In pattern window:
0-9 (in note field are octaves)
А-V (input O,P with Symbol Shift; input Q with Caps Shift)
cs9 - begin/*centre of pattern
*ss9 - end of pattern
L - clear note
*ssL - clear note with parameters
*K - clear command field for current note
Enter - play while hold
ssE - memorize channel into buffer
ssR - recall channel from buffer
*CS(SS)+note - note with octave above(below)
*SS+digit - set Autoscroll
*cs1,cs2 - go to previous,next channel
*True/Inv - go between patterns
*ssY - switch flat/sharp for current note
*csU - set block begin to cursor (including pattern number &
channel)
*csI - set block end to cursor
*csY - copy selected block to cursor
*csT - transpose selected block
*F - empty note (autodata+autoenv+scroll)
*W - on/off Edit melody
*Ext - exit to "Hot keys"
*ssI - Edit smp
*ssU - Edit orn
*csL - edit positions order
*ssA - insert current note parameters into AutoData former
*csA - on/off AutoData
*csE - on/off AutoEnv
*E - on/off transparent envelope entering mode. Note ISN'T being
changed in this mode. Transparent mode is stable if AutoEnv=ON,
in other case it switches itself off after inputting one note
*csW - on/off TurboSound mode
*cs0 - switch between 2 AY chips in TurboSound mode (2nd chip is
in patterns 47..24, these patterns must be in positions list)
2-nd column in pattern - noise shift for all channels.
Special commands (right column in every channel):
Record format: 1234
1 - command type
2 - Delay in commands 1,2,3,9,А
3,4 - depends of command
Command type:
0 - no command
1 - Slide down, fields 3,4 - step. Tone shift if delay=0.
2 - Slide up, fields 3,4 - step. Tone shift if delay=0.
3 - Tone Portamento, fields 3,4 - step, target note is in note
field.
Sample & Ornament will be initialized!
I don't recommend 3xxx from note to SAME note. Have pity to
player!
4 - Sample will play from line # specified in 3,4
5 - same, but for Ornament
6 - Vibrato, in 3 - sound on duration, in 4 - sound off duration
9 - Envelope slide up, fields 3,4 - step
А - Envelope slide down
B - Tempo (3,4)
In positions list (order):
digits - change pattern #
*K - Set loop start
*L - Set loop end
In Edit smp (orn) menu:
*0-9 - octave
*True/Inv - switch between samples (ornaments)
ssU,ssI - switch between ornaments (samples)
W,E - +/-1
R,T - +/-32 (12)
*ss8,ss9 - regulate volume
0 - annul
ssK - change sign
*K - Set loop start (loop is magenta stripe over line numbers -
you can re-set it by mouse)
*L - Set loop end
*A - regulate volume cumulation
*9 - on/off tone frequency cumulation
*F - on/off noise/envelope frequency cumulation
*Y,U,I - on/off T-N-E masks
note keys for hear current sample with current ornament
How to convert track (music channel) from Tempo=6 to Tempo=3:
ss2, Graph, Down, ssW (hold until receiving result)
How to convert track from Tempo=3 to Tempo=6:
ss1, Graph, Down, ssQ (hold until result)
How to clear track quickly:
a) if cursor is in last pattern: Inv,ssE,True,ssR
б) ss1, ssL (hold until result)
Main code: Nick/GDC
Ideas, code, fix, design: Mm<M/Sa9e
Decompile, code, large fix: Alone Coder/i8
(4732) 522-449 Вадим (JV Gfx of GDC)
(4732) 141-962 Николай (Nick of GDC)
(8462) 94-15-95 Сергей (Mm<M) mmcm^yandex.ru
(4912) 75-13-90 Дима (Alone Coder) 2:5029/77.48 Dima Bystrov
390026 Рязань,ул.Высоковольтная д.37 к.1,кв.12 Быстрову Дмитрию
alco^mail.ru
alone_coder^mail.ru
GDC Voronezh, 1997 - Sa9e Samara, 2000 - Invaders Ryazan, 2006
P.S. Save is in disk menu. Don't forget to click SAVE 
Enter key only closes window!
but that's the general idea. 