\ PS2!     c c p-addr --   Data byte (A), high address byte (B), port address (C) - OUT to port with A and B registers set
: PC2! SWAP >< OR PC! ; 
\ SID!     c c --          Data value, register (0-31); bits 5,6 are for interrupt settings; bit 7 (/CS) is handled
: SID!
  2DUP 128 OR 84 PC2!
  2DUP 127 AND 84 PC2!
  128 OR 84 PC2! ;

\ Voice control register flags
: SID:CTL:GATE  1 ;
: SID:CTL:SYNC3 2 ;
: SID:CTL:RING3 4 ;
: SID:CTL:TEST  8 ;
: SID:CTL:TRI   16 ;
: SID:CTL:SAW   32 ;
: SID:CTL:PWM   64 ;
: SID:CTL:NOISE 128 ;

\ Voice 1
\ Reg 0,1 - frequency voice 1
: SID0/1:FREQ! DUP 255 AND 0 SID! >< 255 AND 1 SID! ;
\ Reg 2,3 - pulse wave duty cycle voice 2
: SID2/3:PWM! DUP 255 AND 2 SID! >< 15 AND 3 SID! ;
\ Reg 4 - control register voice 1
: SID4! 4 SID! ;
\ Reg 5 - attack duration / decay duration voice 1
: SID5:ATK/DEC! 15 AND SWAP 4 LSHIFT OR 5 SID! ;
\ Reg 6 - sustain level / release duration voice 1
: SID6:SUS/REL! 15 AND SWAP 4 LSHIFT OR 6 SID! ;

\ Voice 2
\ Reg 7,8 - frequency voice 2
: SID7/8:FREQ! DUP 255 AND 7 SID! >< 15 AND 8 SID! ;
\ Reg 9,10 - pulse wave duty cycle voice 2
: SID9/10:PWM! DUP 255 AND 9 SID! >< 255 AND 10 SID! ;
\ Reg 10 - control register voice 2
: SID11! 11 SID! ;
\ Reg 12 - attack duration / decay duration voice 2
: SID12:ATK/DEC! 15 AND SWAP 4 LSHIFT OR 12 SID! ;
\ Reg 13 - sustain level / release duration voice 2
: SID13:SUS/REL! 15 AND SWAP 4 LSHIFT OR 13 SID! ;

\ Voice 3
\ Reg 14,15 - frequency voice 3
: SID14/15:FREQ! DUP 255 AND 14 SID! >< 15 AND 15 SID! ;
\ Reg 16,17 - pulse wave duty cycle voice 3
: SID16/17:PWM! DUP 255 AND 16 SID! >< 255 AND 17 SID! ;
\ Reg 18 - control register voice 18
: SID18! 18 SID! ;
\ Reg 19 - attack duration / decay duration voice 3
: SID19:ATK/DEC! 15 AND SWAP 4 LSHIFT OR 19 SID! ;
\ Reg 20 - sustain level / release duration voice 3
: SID20:SUS/REL! 15 AND SWAP 4 LSHIFT OR 20 SID! ;

\ Filters
\ Reg 21/22 - filter cutoff frequency (0 - 2047 / 11 bits)
: SID21/22:CUT! DUP 7 AND 21 SID! 3 RSHIFT 255 AND 22 SID! ;
\ Reg 23 - filter resonance (0 - 15 / 4 bits) / ext, voice 3, voice 2, voice 1
: SID23:RES 15 AND 4 LSHIFT ;
: SID23:V1 1 OR ;
: SID23:V2 2 OR ;
: SID23:V3 4 OR ;
: SID23:EXT 8 OR ;
: SID23! 23 SID! ;
\ Reg 24 - filter mode and main volume control
: SID24:VOL 15 AND ;
: SID24:LOWPASS 16 OR ;
: SID24:BANDPASS 32 OR ;
: SID24:HIGHPASS 64 OR ;
: SID24:MUTEVOICE3 128 OR ;
: SID24! 24 SID! ;

\ SID:RST   -- Put SID chip in known state
: SID:RST
   4389 SID0/1:FREQ!   0 SID4!  4 2 SID5:ATK/DEC!  10 9 SID6:SUS/REL!  2048 SID2/3:PWM!
   4389 SID7/8:FREQ!   0 SID11! 4 2 SID12:ATK/DEC! 10 9 SID13:SUS/REL! 2048 SID9/10:PWM!
   4389 SID14/15:FREQ! 0 SID18! 4 2 SID19:ATK/DEC! 10 9 SID20:SUS/REL! 2048 SID16/17:PWM!
   1024 SID21/22:CUT! 10 SID23:RES SID23!
   15 SID24:VOL SID24! ;

\ Frequency table:
: SID:NOTE:C4  4389 ;
: SID:NOTE:C4# 4650 ;
: SID:NOTE:D4  4927 ;
: SID:NOTE:D4# 5220 ;
: SID:NOTE:E4  5530 ;
: SID:NOTE:F4  5859 ;
: SID:NOTE:F4# 6207 ;
: SID:NOTE:G4  6577 ;
: SID:NOTE:G4# 6968 ;
: SID:NOTE:A4  7382 ;
: SID:NOTE:A4# 7821 ;
: SID:NOTE:B4  8286 ;
\ Octave shifts
: SID:OCT:UP 2* ;
: SID:OCT:DOWN 2/ ;

\ Voice contorl registers
VARIABLE SID:V1:CTL
: SID:V1:CTL! SID:V1:CTL ! ;
: SID:V1:NOTE:ON SID0/1:FREQ! SID:V1:CTL @ SID:CTL:GATE OR SID4! ;
: SID:V1:NOTE:OFF SID:V1:CTL @ SID:CTL:GATE INVERT AND SID4! ;

VARIABLE SID:V2:CTL
: SID:V2:CTL! SID:V2:CTL ! ;
: SID:V2:NOTE:ON SID7/8:FREQ! SID:V2:CTL @ SID:CTL:GATE OR SID11! ;
: SID:V2:NOTE:OFF SID:V2:CTL @ SID:CTL:GATE INVERT AND SID11! ;

VARIABLE SID:V3:CTL
: SID:V3:CTL! SID:V3:CTL ! ;
: SID:V3:NOTE:ON SID14/15:FREQ! SID:V3:CTL @ SID:CTL:GATE OR SID18! ;
: SID:V3:NOTE:OFF SID:V3:CTL @ SID:CTL:GATE INVERT AND SID18! ;

: STEP 100 0 DO LOOP ;
: DELAY 10000 0 DO LOOP ;

: SID:V1:TEST:NOTE
   SID:CTL:TRI SID:V1:CTL!
   SID:NOTE:C4 SID:V1:NOTE:ON
   DELAY DELAY
   SID:V1:NOTE:OFF
: SID:V2:TEST:NOTE
   SID:CTL:SAW SID:V2:CTL!
   SID:NOTE:D4 SID:V2:NOTE:ON
   DELAY DELAY
   SID:V2:NOTE:OFF
: SID:V3:TEST:NOTE
   SID:CTL:PWM SID:V3:CTL!
   SID:NOTE:E4 SID:V3:NOTE:ON
   DELAY DELAY
   SID:V3:NOTE:OFF

: SID:TEST:MELODY
   SID:V1:TEST:NOTE
   SID:V2:TEST:NOTE
   SID:V3:TEST:NOTE ;

: SID:TEST:FILTER
   10 SID23:RES SID23:V1 SID23:V2 SID23:V3 SID23:EXT SID23!
   SID:CTL:PWM SID:V3:CTL! SID:NOTE:D4 SID:V3:NOTE:ON
   2047 0 DO I SID21/22:CUT! 1 +LOOP
   SID:V3:NOTE:OFF ;

SID:RST

SID:TEST:MELODY

15 SID24:VOL SID24:LOWPASS SID24!
SID:TEST:FILTER
15 SID24:VOL SID24:BANDPASS SID24!
SID:TEST:FILTER
15 SID24:VOL SID24:HIGHPASS SID24!
SID:TEST:FILTER