defMONing 101: A defMON Operator Field Guide (iLKke, 2013)

A compact survival guide to defmon by iLKke, "the result of my limited defMON knowledge based largely on experimentation… not intended as an exhaustive explanation of the program, but rather a brief survival guide and reference. It assumes basic familiarity with trackers and the SID chip."

Key claims#

The pitch#

• "defMON is what I would call the only true tracker for the C64 (as opposed to sound 'editors'). No tables with pointers to tables, no multiple lines of table data performing a single function. In defMON, screen Y-axis is always time, as in a tracker." (tracker)
• Advantages, per iLKke: single all-powerful instrument table; "no discrimination between instruments & effects (similar to NinjaTracker)" — he calls table entries sidCalls; combine 2 sidCalls at once ("modifiers for instruments instead of duplicating and then modifying"); two cutoff controls "so you can modulate/offset a filter envelope"; relative channel filtering ("filter CURRENT channel"); "Most flexible hard-restart ever, period. Because you do it all yourself. You can have each instrument use a completely different HR."; "Almost any SID tune can be remade in defMON (up to 8x speed, and with the exception of 'digis', or samples)"; adjustable BPM; low rastertime use.
• Disadvantages: "The program is in an eternal beta state. You will receive no tech support"; possible bugs ("You might want to not save too many songs to a disk"); instruments have no names; instrument number must be typed for each note; the packer is built in "but you will need to make a PRG or SID file yourself"; "You might not want to go back."
• Three screens: pattern editor + arranger (main), the sidTAB ("the only table you will ever need… quite similar to siddump output"), disk menu. Per-track columns: note, speed, sidCall1, sidCall2 — "Exact order of these columns can differ depending on defMON version."

Keyboard reference (as of 2013)#

• Navigation: ← switch pattern/sidtab; C=+← / SHIFT+← jump to position in sidtab; CTRL+← switch SID1/SID2; RUN/STOP switch pattern/arranger, exit sidtab; C=+RUN/STOP jump to position in pattern; CTRL+cursor step through patterns/sidtab; SHIFT+X disk menu (RETURN/L load, S save new, SHIFT+S overwrite, SHIFT+P pack, SPACE read dir, W/R legacy format write and read, ,/. prev/next drive, ← exit).
• Playback: F1 play from cursor; F3 play from start; F5 follow on/off; F7 stop/top; [,],= mute tracks ("Ö,Ä,* on Swedish keyboard") — the mute keys of live-tracking use.
• Setup: F2/F4/F6/F8 multispeed; C=+F-keys BPM; SHIFT+F1 BPM reset; CTRL+<,> octave up/down; C=+/ decrease chunk size, SHIFT+/ increase (values 0 = whole table, 1, 2, 4, 8, $10, $20, $40, $80).
• Input: RETURN insert step; SHIFT+RETURN remove step; </> decrease/increase a value; SHIFT+N clone pattern into new, SHIFT+U into unused (arranger); C= and SHIFT edit the two instrument columns; CTRL+C= edit speed column; CTRL+C=+SPACE insert pattern break; C= column edit mode; DEL delete value; SPACE delete value + advance; CTRL+number edit X steps at once.

sidTAB reference#

• JP position jump; DL step delay.
• WG first column (x0): waveform bits +1 triangle, +2 saw, +4 pulse, +8 noise. WG second column (0x): +1 gate on, +2 sync, +4 ringmod, +8 test-bit (reset) (ring-modulation-and-sync).
• ADSR: the volume envelope (adsr-envelope).
• TR: $00–$7F relative pitch up (wraps), $80–$FF absolute notes.
• AF: $00–$19 finetune ($19 = a note up); $21–$7F pitch up (wrap); $80–$BF pitch bend up; $C0–$FF pitch bend down.
• PW pulse width set — "low byte first, then high byte"; PS pulse-width slide: $00–$7F left, $80–$FF right.
• RE — x0 resonance; 0x channel mask, fully enumerated: $00 disable on current, $01 voice 1, $02 voice 2, $03 1+2, $04 voice 3, $05 1+3, $06 2+3, $07 1+2+3, $08 current, $09 current+1, $0A current+2, $0B current+1+2, $0C current+3, $0D current+1+3, $0E current+2+3, $0F current+1+2+3.
• FV filter type (first digit): $00/$80 off, $10/$90 lp, $20/$A0 bp, $30/$B0 lp+bp (high stop), $40/$C0 hp, $50/$D0 lp+hp (band stop), $60/$E0 bp+hp (low stop), $70/$F0 lp+bp+hp (filter-programming).
• CP relative cutoff offset: $00–$7F add, $80–$FF subtract.
• ACID cutoff: $0000–$7FFF set, $8000–$BFFF slide up, $C000–$FFFF slide down.

Transpose table#

• Relative pitches: TR $00–$7F, laid out as octaves 0–10 of 12 semitones ($0C = +1 octave, $18 = +2, … $7F = the top of octave 10).
• Absolute pitches: $81 (C#0) through $F7 (B9), 12 per octave with $8C = C1, $B0 = C4, etc. — the reference the interface-overview page defers to for TR values ≥ $80.

Practical takeaways#

• Treat sidTAB rows as "sidCalls" — one vocabulary for instruments and effects; build modifier chunks (vibrato, slides, filter moves) to combine with instrument chunks via the second call column instead of cloning instruments (instrument-tables).
• The RE mask value $08 (filter the current channel) is the key to writing one reusable filter chunk for all three voices.
• ACID doubles as a cutoff slide command: values $8000+ slide rather than set — combined with CP you get set, offset and sweep from two columns.
• Up to 8x multispeed means nearly any SID tune except sample playback can be covered in defMON.

Notable quotes#

• "defMON is what I would call the only true tracker for the C64."
• "Most flexible hard restart ever, period. Because you do it all yourself."
• "You might not want to go back." (listed as a disadvantage)

Relevance to the wiki#

The canonical quick reference for defmon's sidTAB value ranges — the tables above are the numbers a composer actually needs — and a clear statement of the tracker-vs-editor design argument. Supersedes nothing; extended by s-defmon-wiki-defmoning-102.

Pages touched#

defmon, tracker, hard-restart, multispeed, filter-programming, adsr-envelope, instrument-tables, ring-modulation-and-sync, pitch-slide-and-portamento, detune, pulse-width-modulation, ninjatracker, siddump, live-tracking