MELODY.EL

#OUTPUT PLAYMAKER

' ËEYS:
' ----
'    ÕP ARROW = ÍOVE TO PREVIOUS VOICE
'  ÄOWN ARROW = ÍOVE TO NEXT VOICE
'  ÌEFT ARROW = ÍOVE LEFT WITHIN CURRRENT VOICE STRING
' ÒIGHT ARROW = ÍOVE RIGHT WITHIN CURRENT VOICE STRING
'    ÉÎÓÔ/ÄÅÌ = ÄELETE CHAR IN CURRENT VOICE STRING
'       ÅÓÃ,Ê = ÍOVE TO START OF CURRENT VOICE STRING
'       ÅÓÃ,Ë = ÍOVE TO END OF CURRENT VOICE STRING
'      ÃÔÒÌ+× = ÍOVE FORWARD ONE WORD IN CURRENT VOICE STRING
'      ÃÔÒÌ+Õ = ÍOVE BACK ONE WORD IN CURRENT VOICE STRING
'           < = ÓHOW PREVIOUS SONG CHUNK
'           > = ÓHOW NEXT SONG CHUNK
'           - = ÄECREASE TEMPO
'           + = ÉNCREASE TEMPO
'      ÍÅÇÁ+Ñ = ÑUIT PROGRAM / ÅXIT ÅNV ÅDITOR
'          Æ1 = ÌOAD
'          Æ3 = ÓAVE
'          Æ7 = ÅNVELOPE EDITOR
'          Æ8 = ÆILTER EDITOR
'   Æ9/ÃÔÒÌ-Ð = ÃHUNK SEQUENCER

TRAP RUNSTOP¯TRAPPER

.DECLARATIONS
'------------
#DECLARE CHUNK¯IDX = 0
#DECLARE CHUNK¯CNT = 0
#DEFINE CHUNK¯MAX = 50

#DECLARE VIDX, IDX
#DECLARE CURSOR¯X = 0
#DECLARE CURSOR¯Y = 0

#DECLARE V$(5,CHUNK¯MAX)

#DECLARE KEY$
#DECLARE VALID$="CDEFGAB0123456789 #$.HIQRSWOTUXMPL"
#DECLARE VAL$
#DECLARE TMPO% = 12

#DECLARE ESC¯FLAG% = 0

#STRUCT ÅÎÖÔÙÐÅ NAME$, ATTACK, DECAY, SUSTAIN, RELEASE, WAVEFORM, PW

ÅÎÖÔÙÐÅ ENVS(9) = [ _
  [ "ÐIANO",       0,  9,  0,  0,  2, 1536 ], _
  [ "ÁCCORDION",  12,  0, 12,  0,  1,    0 ], _
  [ "ÃALLIOPE",    0,  0, 15,  0,  0,    0 ], _
  [ "ÄRUM",        0,  5,  5,  0,  3,    0 ], _
  [ "ÆLUTE",       9,  4,  4,  0,  0,    0 ], _
  [ "ÇUITAR",      0,  9,  2,  1,  1,    0 ], _
  [ "ÈARPSICRD",   0,  9,  0,  0,  2,  512 ], _
  [ "ÏRGAN",       0,  9,  9,  0,  2, 2048 ], _
  [ "ÔRUMPET",     8,  9,  4,  1,  2,  512 ], _
  [ "ØYLOPHONE",   0,  9,  0,  0,  0,    0 ]  _
]

#DEFINE ÄÉÒ¯ÎÏÎÅ = 0
#DEFINE ÄÉÒ¯ÕÐ   = 1
#DEFINE ÄÉÒ¯ÄÏ×Î = 2
#DEFINE ÄÉÒ¯ÏÓà  = 3

#DECLARE DIR¯NAME$(3)
DIR¯NAME$(0) = "ÎÏÎÅ"
DIR¯NAME$(1) = "ÕÐ"
DIR¯NAME$(2) = "ÄÏ×Î"
DIR¯NAME$(3) = "ÏÓÃ"

#DEFINE ƯÏÆÆ = 0
#DEFINE ƯÏÎ  = 1

#STRUCT ÆÉÌÔÔÙÐÅ NAME$, FREQ, LP, BP, HP, RES, DIR, MIN, SWEEP

ÆÉÌÔÔÙÐÅ FILT(10) = [ _
  [ "LOWP¯UP",    1000, ƯÏÎ,  ƯÏÆÆ, ƯÏÆÆ, 15, ÄÉÒ¯ÕÐ,   100, 10 ], _
  [ "LOWP¯DOWN",  1000, ƯÏÎ,  ƯÏÆÆ, ƯÏÆÆ, 15, ÄÉÒ¯ÄÏ×Î, 100, 10 ], _
  [ "LOWP¯OSC",   1000, ƯÏÎ,  ƯÏÆÆ, ƯÏÆÆ, 15, ÄÉÒ¯ÏÓÃ,  100, 10 ], _
_
  [ "BANDP¯UP",   1000, ƯÏÆÆ, ƯÏÎ,  ƯÏÆÆ, 15, ÄÉÒ¯ÕÐ,   100, 10 ], _
  [ "BANDP¯DOWN", 1000, ƯÏÆÆ, ƯÏÎ,  ƯÏÆÆ, 15, ÄÉÒ¯ÄÏ×Î, 100, 10 ], _
  [ "BANDP¯OSC",  1000, ƯÏÆÆ, ƯÏÎ,  ƯÏÆÆ, 15, ÄÉÒ¯ÏÓÃ,  100, 10 ], _
_
  [ "HIGHP¯UP",   1000, ƯÏÆÆ, ƯÏÆÆ, ƯÏÎ,  15, ÄÉÒ¯ÕÐ,   100, 10 ], _
  [ "HIGHP¯DOWN", 1000, ƯÏÆÆ, ƯÏÆÆ, ƯÏÎ,  15, ÄÉÒ¯ÄÏ×Î, 100, 10 ], _
  [ "HIGHP¯OSC",  1000, ƯÏÆÆ, ƯÏÆÆ, ƯÏÎ,  15, ÄÉÒ¯ÏÓÃ,  100, 10 ], _
_
  [ "SPARE¯1",    0,    ƯÏÆÆ, ƯÏÆÆ, ƯÏÆÆ, 0,  ÄÉÒ¯ÎÏÎÅ, 0,   0  ], _
  [ "SPARE¯2",    0,    ƯÏÆÆ, ƯÏÆÆ, ƯÏÆÆ, 0,  ÄÉÒ¯ÎÏÎÅ, 0,   0  ], _
_
]

#DECLARE SEQ¯CHUNK(200), SEQ¯EXTRA(200)
#DECLARE ECHO¯M, ECHO¯B, ECHO¯SZ = .05, CHUNK¯RPT, ECHO¯DELAY
#DECLARE V1$, V2$, V3$, V4$, V5$, V6$
#DECLARE TMP
#DECLARE SSCOL, S, SEQ¯OFFS


#DEFINE ÏЯÃÏÐÙ = 0
#DEFINE ÏЯÍÉØ  = 1
#DEFINE ÏЯÓ×ÁÐ = 2
#DEFINE ÏЯÆÉÌÌ = 3

#DEFINE ÓÃÒÎÐÔÒÌÓÂ = $D060
#DEFINE ÓÃÒÎÐÔÒÍÓÂ = $D061
#DEFINE ÓÃÒÎÐÔÒÂÎË = $D062

.CMDS
#DEFINE ÃÍįÔÅÍÐÏ = -1
#DEFINE ÃÍįÆÉÌÔÅÒ = -2
#DEFINE ÃÍįÌÏÏÐ = -3
#DEFINE ÃÍįÅÃÈϯÍ1 = -4   ' ECHO MELODY: VOICE 1 ON VOICE 4
#DEFINE ÃÍįÅÃÈϯÍ2 = -5   ' ECHO MELODY: VOICE 1 ON VOICE 2 + 4 + 5
#DEFINE ÃÍįÅÃÈϯ  = -6   ' ECHO BASS:   VOICE 3 ON VOICE 6
#DEFINE ÃÍįÅÃÈϯÏÆÆ = -7
#DEFINE ÃÍįÅÃÈϯÓÚ = -8
#DEFINE ÃÍįÖÏÌ = -9
#DEFINE ÃÍįÄÅÌÁÙ = -10
#DEFINE ÃÍįÍÁØ = 11

#DECLARE SEQ¯CMDNAME$(10)
SEQ¯CMDNAME$(1) = "ÔÅÍÐÏ"
SEQ¯CMDNAME$(2) = "ÆÉÌÔÅÒ"
SEQ¯CMDNAME$(3) = "ÌÏÏÐ"
SEQ¯CMDNAME$(4) = "ÅÃÈϯÍ1"
SEQ¯CMDNAME$(5) = "ÅÃÈϯÍ2"
SEQ¯CMDNAME$(6) = "ÅÃÈϯÂ"
SEQ¯CMDNAME$(7) = "ÅÃÈϯÏÆÆ"
SEQ¯CMDNAME$(8) = "ÅÃÈϯÓÚ"
SEQ¯CMDNAME$(9) = "ÖÏÌ"
SEQ¯CMDNAME$(10) = "ÄÅÌÁÙ"

#DECLARE SEQCNT, SEQPTR

#DECLARE ROW, COL, SROW, SCOL, A$, V, MAXV, V$

#STRUCT ËÅÙ¯ÔÙÐÅ IN$, OUT$

ËÅÙ¯ÔÙÐÅ KEYS(11) = [ _
  [ "A", "C", ], _
  [ "W", "#C", ], _
  [ "S", "D", ], _
  [ "E", "#D", ], _
  [ "D", "E", ], _
  [ "F", "F", ], _
  [ "T", "#F", ], _
  [ "G", "G", ], _
  [ "Y", "#G", ], _
  [ "H", "A", ], _
  [ "U", "#A", ], _
  [ "J", "B", ] _
]

#DECLARE PSTR$, K, DELTA

#DECLARE WNAME$(4)
WNAME$(0) = "ÔÒÉ"
WNAME$(1) = "ÓÁ×"
WNAME$(2) = "ÐÕÌÓÅ"
WNAME$(3) = "ÎÏÉÓÅ"
WNAME$(4) = "ÒÉÎÇ"

#DECLARE FILT¯STATE¯NAME$(2)
FILT¯STATE¯NAME$(0) = "ÏÆÆ"
FILT¯STATE¯NAME$(1) = "ÏÎ"

#DECLARE FPRESET = 1

#DECLARE FSCOL = 0, FSROW = 0, FFOCUS = 0, FSEL = -1
#DECLARE OCT = 5

#DECLARE CURR¯FREQ, CURR¯DIR
#DECLARE HANDLED
#DECLARE PLYPTR = -1, PLYFLAG

.DURATION
'--------
#DEFINE ÄÎÁÍÅ = 0
#DEFINE ÄÃÈÁÒ = 1
#DEFINE ÄËÅÙ  = 2

#DEFINE į×ÈÏÌÅ = 0
#DEFINE įÈÁÌÆ = 1
#DEFINE įÑÕÁÒÔÅÒ = 2
#DEFINE įÅÉÇÈÔÈ = 3
#DEFINE įÓÉØÔÅÅÎÔÈ = 4

#DECLARE SDUR = 2
#DECLARE DUR$(5,2)
DUR$(į×ÈÏÌÅ, ÄÎÁÍÅ) = "WHOLE"
DUR$(į×ÈÏÌÅ, ÄÃÈÁÒ) = "W"
DUR$(į×ÈÏÌÅ, ÄËÅÙ)  = "1"

DUR$(įÈÁÌÆ, ÄÎÁÍÅ) = "HALF"
DUR$(įÈÁÌÆ, ÄÃÈÁÒ) = "H"
DUR$(įÈÁÌÆ, ÄËÅÙ)  = "2"

DUR$(įÑÕÁÒÔÅÒ, ÄÎÁÍÅ) = "QUARTER"
DUR$(įÑÕÁÒÔÅÒ, ÄÃÈÁÒ) = "Q"
DUR$(įÑÕÁÒÔÅÒ, ÄËÅÙ)  = "3"

DUR$(įÅÉÇÈÔÈ, ÄÎÁÍÅ) = "EIGHTH"
DUR$(įÅÉÇÈÔÈ, ÄÃÈÁÒ) = "I"
DUR$(įÅÉÇÈÔÈ, ÄËÅÙ)  = "4"

DUR$(įÓÉØÔÅÅÎÔÈ, ÄÎÁÍÅ) = "SIXTEENTH"
DUR$(įÓÉØÔÅÅÎÔÈ, ÄÃÈÁÒ) = "S"
DUR$(įÓÉØÔÅÅÎÔÈ, ÄËÅÙ)  = "5"

#DECLARE CLIP$, ALT¯KEY, LIMIT, RET%, Y, CP$(6)

.KEYS
'----
#DEFINE ËÅÙ¯ÕÐ = "‘"
#DEFINE ËÅÙ¯ÄÏ×Î = ""
#DEFINE ËÅÙ¯ÌÅÆÔ = ""
#DEFINE ËÅÙ¯ÒÉÇÈÔ = ""
#DEFINE ËÅÙ¯ÓÐÁÃÅ = " "
#DEFINE ËÅÙ¯ÄÅÌ = ""
#DEFINE ËÅÙ¯ÃÔÒÌ¯× = ""
#DEFINE ËÅÙ¯ÃÔÒÌ¯Õ = ""
#DEFINE ËÅÙ¯ÍÅÇÁ¯Ñ = "«"
#DEFINE ËÅÙ¯Æ1 = "…"
#DEFINE ËÅÙ¯Æ3 = "†"
#DEFINE ËÅÙ¯Æ4 = "Š"
#DEFINE ËÅÙ¯Æ7 = "ˆ"
#DEFINE ËÅÙ¯Æ8 = "Œ"
#DEFINE ËÅÙ¯Æ9 = CHR$(16)
#DEFINE ËÅÙ¯ÒÅÔÕÒÎ = CHR$(13)
#DEFINE ËÅÙ¯ÅÓÃÁÐÅ = CHR$(27)
#DEFINE ËÅÙ¯ÓÈÉÆÔ¯ÒÅÔÕÒÎ = CHR$(141)
#DEFINE ËÅÙ¯ÓÈÉÆÔ¯ÐÌÕÓ = "Û"
#DEFINE ËÅÙ¯ÓÈÉÆÔ¯ÍÉÎÕÓ = "Ý"
#DEFINE ËÅÙ¯ÒÅÖ¯ÏÎ = ""
#DEFINE ËÅÙ¯ÒÅÖ¯ÏÆÆ = "’"
#DEFINE ËÅÙ¯ÔÁÂ = CHR$(9)
#DEFINE ËÅÙ¯ÈÏÍÅ = ""
#DEFINE ËÅÙ¯ÃÌÒ  = "“"
#DEFINE ËÅÙ¯ÌÏ×ÅÒÃÁÓÅ = CHR$(14)
#DEFINE ËÅÙ¯ÕÐÐÅÒÃÁÓÅ = CHR$(142)
#DEFINE ËÅÙ¯ÂÅÅÐ = CHR$(7)
#DEFINE ËÅÙ¯ÉÎÓÔ = "”"
#DEFINE ËÅÙ¯ÄÅÌ  = ""

.INIT
'----
PRINT "“";ËÅÙ¯ÌÏ×ÅÒÃÁÓÅ;ËÅÙ¯ÅÓÃÁÐÅ;"5";
PLAY : PLAY ""
BACKGROUND 0 : BORDER 0
COLOR 5

.MAIN
'----
  KEY OFF
  GOSUB DRAW¯EDITOR¯SCREEN
  GOSUB USER¯INPUT
  GOTO MAIN

.DRAW¯EDITOR¯SCREEN
'------------------
  CURSOR 0,0:PRINT "“PLAYMAKER V0.5 - BY GURCE ISIKYILDIZ"
  PRINT "---------"
  PRINT "<: PREV CHUNK, >: NEXT CHUNK, -/+ TEMPO, Æ7=ENV EDITOR, Æ9/ÃÔÒÌ-Ð=SEQ EDITOR"
  PRINT "ÒÔÎ: PLAY CURR VOICE, ÓÈÆÔ+ÒÔÎ: PLAY ALL VOICE, Æ1=LOAD, Æ3=SAVE, ÍÅÇÁ+Ñ=QUIT"
  PRINT "ÁÌÔ-Ø/Ã/Ö: ROW CUT/COPY/PASTE, ÅÓÃ-ÅÓÃ: STOP MUSIC, ÁÌÔ-ÒÔÎ: PLAY FROM CURSOR"
  PRINT

  GOSUB DRAW¯CURRENT¯CHUNK
  RETURN

.DRAW¯CURRENT¯CHUNK
'------------------
  PRINT "TEMPO: "; TMPO%
  PRINT "CHUNK¯IDX: "; CHUNK¯IDX  
   
  FOR VIDX=0 TO 5
    IF CURSOR¯Y <> VIDX THEN BEGIN
      CURSOR 0,9+VIDX*2:PRINT CHR$(27);"Q";"V";VIDX+1;": ";V$(VIDX,CHUNK¯IDX);
    BEND:ELSE BEGIN
      CURSOR 0,9+VIDX*2:PRINT CHR$(27);"Q";"V";VIDX+1;": ";
      FOR IDX=1 TO LEN(V$(VIDX,CHUNK¯IDX))
        IF CURSOR¯X = IDX-1 THEN BEGIN
          PRINT "";MID$(V$(VIDX,CHUNK¯IDX),IDX,1);"’";
        BEND:ELSE BEGIN
          PRINT MID$(V$(VIDX,CHUNK¯IDX),IDX,1);
        BEND
      NEXT IDX
      IF LEN(V$(VIDX,CHUNK¯IDX)) = 0 OR CURSOR¯X=LEN(V$(VIDX,CHUNK¯IDX)) THEN PRINT " ’";
    BEND
  NEXT VIDX
  RETURN

.CHECK¯VALID¯KEY
'---------------
  FOR IDX=1 TO LEN(VALID$)
    VAL$=MID$(VALID$,IDX,1)
    IF KEY$= VAL$ THEN BEGIN
      IF CURSOR¯X < LEN(V$(CURSOR¯Y,CHUNK¯IDX)) THEN BEGIN
        V$(CURSOR¯Y,CHUNK¯IDX) = LEFT$(V$(CURSOR¯Y,CHUNK¯IDX),CURSOR¯X) _
          + VAL$ + MID$(V$(CURSOR¯Y,CHUNK¯IDX),CURSOR¯X+1)
        CURSOR¯X=CURSOR¯X+1
        RETURN
      BEND
      V$(CURSOR¯Y,CHUNK¯IDX)=V$(CURSOR¯Y,CHUNK¯IDX)+VAL$
      CURSOR¯X=CURSOR¯X+1
      RETURN
    BEND
  NEXT IDX
  RETURN

.FORWARD¯WORD
'------------
  IF CURSOR¯X = LEN(V$(CURSOR¯Y,CHUNK¯IDX)) THEN RETURN

  DO WHILE MID$(V$(CURSOR¯Y,CHUNK¯IDX),CURSOR¯X+1,1) <> " "
    CURSOR¯X=CURSOR¯X+1
    IF CURSOR¯X = LEN(V$(CURSOR¯Y,CHUNK¯IDX)) THEN RETURN
  LOOP
  DO WHILE MID$(V$(CURSOR¯Y,CHUNK¯IDX),CURSOR¯X+1,1) = " "
    CURSOR¯X=CURSOR¯X+1
    IF CURSOR¯X = LEN(V$(CURSOR¯Y,CHUNK¯IDX)) THEN RETURN
  LOOP

  RETURN

.PREVIOUS¯WORD
'-------------
  IF CURSOR¯X = 0 THEN RETURN
  IF CURSOR¯X = 1 THEN CURSOR¯X = 0: RETURN

  CURSOR¯X = CURSOR¯X - 1
  DO WHILE MID$(V$(CURSOR¯Y,CHUNK¯IDX),CURSOR¯X+1,1) = " "
    CURSOR¯X=CURSOR¯X-1
    IF CURSOR¯X = 0 THEN RETURN
  LOOP
  DO WHILE MID$(V$(CURSOR¯Y,CHUNK¯IDX),CURSOR¯X+1,1) <> " "
    CURSOR¯X=CURSOR¯X-1
    IF CURSOR¯X = 0 THEN RETURN
  LOOP
  CURSOR¯X=CURSOR¯X+1

  RETURN

.SET¯ALL¯ENV
'-----------
  FOR ROW = 0 TO 9
    GOSUB SET¯ENV
  NEXT ROW
  RETURN

.LOAD
'----
  INPUT "LOAD NAME: ";KEY$
  IF KEY$="" THEN RETURN

  DOPEN #2,(KEY$),R,U8

  ' LOAD MELODY CHUNKS
  ' ------------------
  INPUT #2, CHUNK¯CNT
  FOR CHUNK¯IDX = 0 TO CHUNK¯CNT - 1
    FOR VIDX=0 TO 5
      INPUT #2,V$(VIDX, CHUNK¯IDX)
    NEXT VIDX
  NEXT CHUNK¯IDX

  INPUT #2,TMPO%
  
  ' LOAD ENVELOPES
  ' --------------
  FOR ROW = 0 TO 9
    INPUT #2, ENVS¯NAME$(ROW)
    INPUT #2, ENVS¯ATTACK(ROW)
    INPUT #2, ENVS¯DECAY(ROW)
    INPUT #2, ENVS¯SUSTAIN(ROW)
    INPUT #2, ENVS¯RELEASE(ROW)
    INPUT #2, ENVS¯WAVEFORM(ROW)
    INPUT #2, ENVS¯PW(ROW)
    GOSUB SET¯ENV
  NEXT ROW
  PRINT

  ' LOAD FILTER PRESETS
  ' -------------------
  FOR ROW = 0 TO 10
    INPUT #2, FILT¯NAME$(ROW)
    INPUT #2, FILT¯FREQ(ROW)
    INPUT #2, FILT¯LP(ROW)
    INPUT #2, FILT¯BP(ROW)
    INPUT #2, FILT¯HP(ROW)
    INPUT #2, FILT¯RES(ROW)
    INPUT #2, FILT¯DIR(ROW)
    INPUT #2, FILT¯MIN(ROW)
    INPUT #2, FILT¯SWEEP(ROW)
  NEXT ROW

  ' LOAD SEQUENCE
  ' -------------
  SEQCNT = 0
  INPUT #2, SEQCNT
  ROW = 0
  DO WHILE ROW < SEQCNT
    INPUT #2, SEQ¯CHUNK(ROW)
    INPUT #2, SEQ¯EXTRA(ROW)
    ROW = ROW + 1
  LOOP


  DCLOSE #2

  CHUNK¯IDX = 0
  RETURN

.GET¯CHUNK¯CNT
'-------------
  CHUNK¯CNT = 0
  FOR K = 0 TO CHUNK¯MAX
    IF V$(0,K)<>"" OR V$(1,K)<>"" OR V$(2,K)<>"" OR V$(3,K)<>"" OR V$(4,K)<>"" OR V$(5,K)<>"" THEN BEGIN
      CHUNK¯CNT = K + 1
    BEND
  NEXT K

  RETURN


.SAVE
'----
  INPUT "SAVE NAME: ";KEY$
  IF KEY$="" THEN RETURN
  
  DELETE (KEY$)
  DOPEN #2,(KEY$),W,U8
  TMP = CHUNK¯IDX

  ' SAVE MELODY CHUNKS
  ' ------------------
  GOSUB GET¯CHUNK¯CNT
  PRINT #2, CHUNK¯CNT
  FOR CHUNK¯IDX = 0 TO CHUNK¯CNT - 1
    FOR VIDX=0 TO 5
      PRINT #2,V$(VIDX, CHUNK¯IDX)
    NEXT VIDX
  NEXT CHUNK¯IDX
  PRINT #2,TMPO%

  ' SAVE ENVELOPES
  ' --------------
  FOR ROW = 0 TO 9
    PRINT #2, ENVS¯NAME$(ROW)
    PRINT #2, ENVS¯ATTACK(ROW)
    PRINT #2, ENVS¯DECAY(ROW)
    PRINT #2, ENVS¯SUSTAIN(ROW)
    PRINT #2, ENVS¯RELEASE(ROW)
    PRINT #2, ENVS¯WAVEFORM(ROW)
    PRINT #2, ENVS¯PW(ROW)
  NEXT ROW

  ' SAVE FILTER PRESETS
  ' -------------------
  FOR ROW = 0 TO 10
    PRINT #2, FILT¯NAME$(ROW)
    PRINT #2, FILT¯FREQ(ROW)
    PRINT #2, FILT¯LP(ROW)
    PRINT #2, FILT¯BP(ROW)
    PRINT #2, FILT¯HP(ROW)
    PRINT #2, FILT¯RES(ROW)
    PRINT #2, FILT¯DIR(ROW)
    PRINT #2, FILT¯MIN(ROW)
    PRINT #2, FILT¯SWEEP(ROW)
  NEXT ROW

  ' SAVE SEQUENCE
  ' -------------
  PRINT #2, SEQCNT
  ROW = 0
  DO WHILE ROW < SEQCNT
    PRINT #2, SEQ¯CHUNK(ROW)
    PRINT #2, SEQ¯EXTRA(ROW)
    ROW = ROW + 1
  LOOP

  DCLOSE #2

  CHUNK¯IDX = TMP
  RETURN

.SAVE¯AS¯TEXT
'------------
  INPUT "SAVE (AS TEXT) NAME: ";KEY$
  IF KEY$="" THEN RETURN

  DELETE (KEY$)
    
  DOPEN #2,(KEY$),W,U8
  FOR CHUNK¯IDX = 0 TO CHUNK¯MAX
    FOR VIDX=0 TO 5
      PRINT #2, "V";CHR$(49+VIDX);"$(";STR$(CHUNK¯IDX);")=";
      PRINT #2, CHR$(34);V$(VIDX, CHUNK¯IDX);CHR$(34)
    NEXT VIDX  
    PRINT #2, ""
  NEXT CHUNK¯IDX
  DCLOSE #2

  CHUNK¯IDX = 0
  RETURN


.USER¯INPUT
'----------
  ' GETKEY KEY$
  GOSUB READ¯KEY¯LOOP
  KEY$ = A$

  GOSUB CHECK¯ALT¯KEY¯INPUTS

  ' DOWN ARROW?
  IF KEY$ = ËÅÙ¯ÄÏ×Î AND CURSOR¯Y<5 THEN BEGIN
    CURSOR¯Y = CURSOR¯Y + 1
    IF CURSOR¯X > LEN(V$(CURSOR¯Y,CHUNK¯IDX)) THEN CURSOR¯X = _
      LEN(V$(CURSOR¯Y,CHUNK¯IDX))
  BEND

  ' UP ARROW?
  IF KEY$ = ËÅÙ¯ÕÐ AND CURSOR¯Y>0 THEN BEGIN
    CURSOR¯Y = CURSOR¯Y - 1
    IF CURSOR¯X > LEN(V$(CURSOR¯Y,CHUNK¯IDX)) THEN _
      CURSOR¯X = LEN(V$(CURSOR¯Y,CHUNK¯IDX))
  BEND

  ' RIGHT ARROW?
  IF KEY$ = ËÅÙ¯ÒÉÇÈÔ AND CURSOR¯X < LEN(V$(CURSOR¯Y,CHUNK¯IDX)) THEN BEGIN
    CURSOR¯X=CURSOR¯X+1
  BEND

  ' LEFT ARROW?
  IF KEY$ = ËÅÙ¯ÌÅÆÔ AND CURSOR¯X > 0 THEN CURSOR¯X=CURSOR¯X-1

  ' BACKSPACE (INST/DEL)?
  IF KEY$ = ËÅÙ¯ÄÅÌ AND CURSOR¯X > 0 THEN BEGIN
    V$(CURSOR¯Y,CHUNK¯IDX)=LEFT$(V$(CURSOR¯Y,CHUNK¯IDX),CURSOR¯X-1) _
      + MID$(V$(CURSOR¯Y,CHUNK¯IDX),CURSOR¯X+1)
    CURSOR¯X=CURSOR¯X-1
  BEND

  IF ESC¯FLAG% THEN BEGIN
    ESC¯FLAG%=0
    IF KEY$ = "J" THEN BEGIN:CURSOR¯X=0:BEND
    IF KEY$ = "K" THEN BEGIN:CURSOR¯X=LEN(V$(CURSOR¯Y,CHUNK¯IDX)):BEND
    IF KEY$=ËÅÙ¯ÅÓÃÁÐÅ THEN GOSUB STOP¯ALL¯MUSIC
    KEY$=""
  BEND

  IF KEY$ = ËÅÙ¯ÅÓÃÁÐÅ THEN ESC¯FLAG%=ABS(ESC¯FLAG%-1)

  ' CTRL-W = FORWARD ONE WORD
  IF KEY$ = ËÅÙ¯ÃÔÒÌ¯× THEN GOSUB FORWARD¯WORD

  ' CTRL-U = BACK ONE WORD
  IF KEY$ = ËÅÙ¯ÃÔÒÌ¯Õ THEN GOSUB PREVIOUS¯WORD

  ' < / > = PREVIOUS/NEXT CHUNK
  IF KEY$ = "<" AND CHUNK¯IDX>0 THEN BEGIN
    CHUNK¯IDX=CHUNK¯IDX-1
    CURSOR¯X=0
  BEND
  IF KEY$ = ">" AND CHUNK¯IDX<CHUNK¯MAX THEN BEGIN
    CHUNK¯IDX=CHUNK¯IDX+1
    CURSOR¯X=0
  BEND

  ' +/- = TEMPO CHANGE
  IF KEY$="-" THEN TMPO%=TMPO%-1
  IF KEY$="+" THEN TMPO%=TMPO%+1

  ' MEGA-Q = EXIT
  IF KEY$ = ËÅÙ¯ÍÅÇÁ¯Ñ THEN BEGIN
    PRINT "ARE YOU SURE? (Y/N)"
    GET KEY A$
    IF A$="Y" THEN KEY ON:END
  BEND

  IF KEY$ = ËÅÙ¯Æ1 THEN GOSUB LOAD
  IF KEY$ = ËÅÙ¯Æ3 THEN GOSUB SAVE
  IF KEY$ = ËÅÙ¯Æ7 THEN GOSUB ENVELOPE¯EDITOR
  IF KEY$ = ËÅÙ¯Æ9 THEN GOSUB CHUNK¯SEQUENCER

  ' Æ4 = SAVE AS TEXT
  IF KEY$ = ËÅÙ¯Æ4 THEN GOSUB SAVE¯AS¯TEXT

  ' RETURN=PLAY ROW
  IF KEY$ = ËÅÙ¯ÒÅÔÕÒÎ THEN TEMPO TMPO% : PLAY V$(CURSOR¯Y,CHUNK¯IDX)

  ' SHIFT+RETURN=PLAY ALL CHANNELS
  IF KEY$ = ËÅÙ¯ÓÈÉÆÔ¯ÒÅÔÕÒÎ THEN BEGIN
    TEMPO TMPO%
    GOSUB PLAY¯CHUNK¯IDX
  BEND

  IF KEY$ = ËÅÙ¯ÉÎÓÔ THEN BEGIN
    V1$ = V$(CURSOR¯Y, CHUNK¯IDX)
    V1$ = LEFT$(V1$,CURSOR¯X) + MID$(V1$,CURSOR¯X+2)
    V$(CURSOR¯Y, CHUNK¯IDX) = V1$
  BEND

  GOSUB CHECK¯VALID¯KEY
  RETURN

.CHECK¯ALT¯KEY¯INPUTS
'--------------------
  ALT¯KEY = PEEK($D611) AND 16

  IF ALT¯KEY = 0 THEN RETURN

  IF KEY$="X" THEN CLIP$=V$(CURSOR¯Y, CHUNK¯IDX) : V$(CURSOR¯Y, CHUNK¯IDX) = ""
  IF KEY$="C" THEN CLIP$=V$(CURSOR¯Y, CHUNK¯IDX)
  IF KEY$="V" THEN V$(CURSOR¯Y, CHUNK¯IDX) = CLIP$
  IF KEY$="Ã" THEN GOSUB COPY¯ALL¯VOICES¯TO¯CLIPBOARD
  IF KEY$="Ö" THEN GOSUB PASTE¯ALL¯VOICES¯FROM¯CLIPBOARD

  IF KEY$=ËÅÙ¯ÒÅÔÕÒÎ THEN BEGIN
    V1$ = MID$(V$(CURSOR¯Y, CHUNK¯IDX), CURSOR¯X + 1)
    TEMPO TMPO% : PLAY V1$
  BEND

  IF KEY$="," THEN DELTA = -1 : GOSUB TRANSPOSE¯OCTAVE
  IF KEY$="." THEN DELTA = 1  : GOSUB TRANSPOSE¯OCTAVE
  IF KEY$="I" THEN GOSUB INSERT¯CHUNK

  KEY$ = ""
  RETURN

.COPY¯ALL¯VOICES¯TO¯CLIPBOARD
'----------------------------
  FOR Y = 0 TO 5
    CP$(Y) = V$(Y, CHUNK¯IDX)
  NEXT Y
  RETURN

.PASTE¯ALL¯VOICES¯FROM¯CLIPBOARD
'-------------------------------
  FOR Y = 0 TO 5
    V$(Y, CHUNK¯IDX) = CP$(Y)
  NEXT Y
  RETURN

.INSERT¯CHUNK
'------------
  FOR K = CHUNK¯MAX-1 TO CHUNK¯IDX + 1 STEP -1
    FOR Y = 0 TO 5
      V$(Y, K) = V$(Y, K-1)
    NEXT Y
  NEXT K

  FOR Y = 0 TO 5
    V$(Y, CHUNK¯IDX) = ""
  NEXT Y

  ' REPAIR ITEMS IN THE SEQUENCE THAT ARE AFFECTED
  FOR K = 0 TO 100
    IF SEQ¯CHUNK(K) >= CHUNK¯IDX THEN SEQ¯CHUNK(K) = SEQ¯CHUNK(K) + 1
  NEXT K

  RETURN

.TRANSPOSE¯OCTAVE
'----------------
  V1$ = V$(CURSOR¯Y, CHUNK¯IDX)

  LIMIT = 0
  IF DELTA = 1 THEN LIMIT = 6

  RET% = 0
  GOSUB CAN¯TRANSPOSE¯OCTAVE

  IF RET% = 0 THEN PRINT ËÅÙ¯ÂÅÅÐ; : RETURN

  K = 0
  DO WHILE K < LEN(V1$)
    V2$ = MID$(V1$,K+1,1)
    IF V2$ = "O" AND (K + 1) < LEN(V1$) THEN BEGIN
      V2$ = STR$(VAL(MID$(V1$,K+2,1)) + DELTA)
      V2$ = MID$(V2$,2)
      V1$ = LEFT$(V1$,K+1) + V2$ + MID$(V1$, K+3)
    BEND
    K = K + 1
  LOOP

  V$(CURSOR¯Y, CHUNK¯IDX) = V1$

  RETURN

.CAN¯TRANSPOSE¯OCTAVE
'--------------------
  RET% = 1

  K = 0
  DO WHILE K < LEN(V1$)
    V2$ = MID$(V1$,K+1,1)
    IF V2$ = "O" AND (K+1) < LEN(V1$) THEN BEGIN
      V2$ = MID$(V1$,K+2,1)
      IF VAL(V2$) = LIMIT THEN RET% = 0 : RETURN
    BEND

    K = K + 1
  LOOP

  RETURN

.PLAY¯CHUNK¯IDX
'--------------
  V1$ = V$(0,CHUNK¯IDX)
  V2$ = V$(1,CHUNK¯IDX)
  V3$ = V$(2,CHUNK¯IDX)
  V4$ = V$(3,CHUNK¯IDX)
  V5$ = V$(4,CHUNK¯IDX)
  V6$ = V$(5,CHUNK¯IDX)

  IF ECHO¯DELAY = 1 THEN BEGIN
    PLAY V1$
    SLEEP (ECHO¯SZ)
    PLAY ,V2$
    SLEEP (ECHO¯SZ)
    PLAY ,,V3$
    SLEEP (ECHO¯SZ)
    PLAY ,,,V4$
    SLEEP (ECHO¯SZ)
    PLAY ,,,,V5$
    SLEEP (ECHO¯SZ)
    PLAY ,,,,,V6$
    SLEEP (ECHO¯SZ)
    RETURN
  BEND

  IF ECHO¯M = 0 AND ECHO¯B = 0 THEN BEGIN
    PLAY V1$, V2$, V3$, V4$, V5$, V6$
    RETURN
  BEND

  IF ECHO¯M = 1 AND ECHO¯B = 0 THEN BEGIN
    PLAY V1$, V2$, V3$,    , V5$, V6$
    SLEEP (ECHO¯SZ)
    PLAY    ,    ,    , V1$
  BEND

  IF ECHO¯M = 1 AND ECHO¯B = 1 THEN BEGIN
    PLAY V1$, V2$, V3$,    , V5$
    SLEEP (ECHO¯SZ)
    PLAY    ,    ,    , V1$,    , V3$
  BEND

  IF ECHO¯M = 2 AND ECHO¯B = 0 THEN BEGIN
    PLAY V1$,    , V3$,    ,    , V6$
    SLEEP (ECHO¯SZ)
    PLAY    ,    ,    , V1$
    SLEEP (ECHO¯SZ)
    PLAY    , V1$
    SLEEP (ECHO¯SZ)
    PLAY    ,    ,    ,    , V1$
  BEND

  IF ECHO¯M = 2 AND ECHO¯B = 1 THEN BEGIN
    PLAY V1$,    , V3$
    SLEEP (ECHO¯SZ)
    PLAY    ,    ,    , V1$
    SLEEP (ECHO¯SZ)
    PLAY    , V1$,    ,    ,    , V3$
    SLEEP (ECHO¯SZ)
    PLAY    ,    ,    ,    , V1$
  BEND

  RETURN

.ENVELOPE¯EDITOR
'---------------
  DO WHILE 1
    GOSUB DRAW¯TABLE
    GOSUB GET¯USER¯INPUT¯FOR¯TABLE

    ' ALT+Q TO EXIT
    IF A$ = ËÅÙ¯ÍÅÇÁ¯Ñ THEN EXIT
  LOOP
  RETURN



.DRAW¯TABLE
'----------
  PRINT "“ENV EDITOR";ËÅÙ¯ÔÁÂ;DUR$(SDUR, ÄÎÁÍÅ);ËÅÙ¯ÔÁÂ;"OCTAVE";OCT
  PRINT "----------"
  PRINT "-/+: DECR/INCR, </>: OCTAVE, ÒÔÎ: EDIT, ÔÁÂ: FOCUS ENV/FILTER, ÍÅÇÁ+Ñ: EXIT"
  PRINT
  PRINT "   ÎÁÍÅ";ËÅÙ¯ÔÁÂ;ËÅÙ¯ÔÁÂ;"ÁÔÔÁÃË";ËÅÙ¯ÔÁÂ;"ÄÅÃÁÙ";ËÅÙ¯ÔÁÂ;"ÓÕÓÔÁÉÎ";ËÅÙ¯ÔÁÂ;"ÒÅÌÅÁÓÅ";ËÅÙ¯ÔÁÂ;
  PRINT "×ÁÖÅÆÒÍ";ËÅÙ¯ÔÁÂ;"ÐÕÌÓÅ×ÉÄÔÈ"

  FOR ROW = 0 TO 9
    IF SROW = ROW THEN PRINT ">";:ELSE PRINT " ";
    PRINT ROW;": ";
    COL = 0 : V$ = ENVS¯NAME$(ROW)
    GOSUB SHOW¯CELL
    COL = 1 : V = ENVS¯ATTACK(ROW)
    GOSUB SHOW¯CELL
    COL = 2 : V = ENVS¯DECAY(ROW)
    GOSUB SHOW¯CELL
    COL = 3 : V = ENVS¯SUSTAIN(ROW)
    GOSUB SHOW¯CELL
    COL = 4 : V = ENVS¯RELEASE(ROW)
    GOSUB SHOW¯CELL
    COL = 5 : V = ENVS¯WAVEFORM(ROW)
    GOSUB SHOW¯CELL
    COL = 6 : V = ENVS¯PW(ROW)
    GOSUB SHOW¯CELL
    PRINT
  NEXT ROW

  PRINT
  PRINT "FILTER EDITOR"
  PRINT "-------------";
  PRINT ËÅÙ¯ÔÁÂ;"FREQ";ËÅÙ¯ÔÁÂ;"LP";ËÅÙ¯ÔÁÂ;"BP";ËÅÙ¯ÔÁÂ;"HP";ËÅÙ¯ÔÁÂ;"RES";
  PRINT ËÅÙ¯ÔÁÂ;"DIR";ËÅÙ¯ÔÁÂ;"MIN";ËÅÙ¯ÔÁÂ;"SWEEP"

  FOR FPRESET = 0 TO 10
    GOSUB SHOW¯FILTER
  NEXT FPRESET

  RETURN


.SHOW¯FILTER
'-----------
  IF FSEL = FPRESET THEN PRINT ">";:ELSE PRINT " ";

  K = 0 : GOSUB CHECK¯SHOW¯FILTER¯HIGHLIGHT
  PRINT FILT¯NAME$(FPRESET);"  ";ËÅÙ¯ÔÁÂ;

  K = 1 : GOSUB CHECK¯SHOW¯FILTER¯HIGHLIGHT
  PRINT FILT¯FREQ(FPRESET);ËÅÙ¯ÔÁÂ;

  K = 2 : GOSUB CHECK¯SHOW¯FILTER¯HIGHLIGHT
  PRINT FILT¯STATE¯NAME$(FILT¯LP(FPRESET));ËÅÙ¯ÔÁÂ;

  K = 3 : GOSUB CHECK¯SHOW¯FILTER¯HIGHLIGHT
  PRINT FILT¯STATE¯NAME$(FILT¯BP(FPRESET));ËÅÙ¯ÔÁÂ;

  K = 4 : GOSUB CHECK¯SHOW¯FILTER¯HIGHLIGHT
  PRINT FILT¯STATE¯NAME$(FILT¯HP(FPRESET));ËÅÙ¯ÔÁÂ;

  K = 5 : GOSUB CHECK¯SHOW¯FILTER¯HIGHLIGHT
  PRINT FILT¯RES(FPRESET);ËÅÙ¯ÔÁÂ;

  K = 6 : GOSUB CHECK¯SHOW¯FILTER¯HIGHLIGHT
  PRINT DIR¯NAME$(FILT¯DIR(FPRESET));ËÅÙ¯ÔÁÂ;

  K = 7 : GOSUB CHECK¯SHOW¯FILTER¯HIGHLIGHT
  PRINT FILT¯MIN(FPRESET);ËÅÙ¯ÔÁÂ;

  K = 8 : GOSUB CHECK¯SHOW¯FILTER¯HIGHLIGHT
  PRINT FILT¯SWEEP(FPRESET);

  PRINT ËÅÙ¯ÒÅÖ¯ÏÆÆ
  RETURN

.CHECK¯SHOW¯FILTER¯HIGHLIGHT
'---------------------------
  IF FSROW = FPRESET AND FFOCUS = 1 AND FSCOL = K THEN _
    PRINT ËÅÙ¯ÒÅÖ¯ÏÎ; : ELSE PRINT ËÅÙ¯ÒÅÖ¯ÏÆÆ;
  RETURN


.GET¯VAL
'-------
  IF SCOL = 0 THEN V$ = ENVS¯NAME$(SROW)
  IF SCOL = 1 THEN V = ENVS¯ATTACK(SROW)
  IF SCOL = 2 THEN V = ENVS¯DECAY(SROW)
  IF SCOL = 3 THEN V = ENVS¯SUSTAIN(SROW)
  IF SCOL = 4 THEN V = ENVS¯RELEASE(SROW)
  IF SCOL = 5 THEN V = ENVS¯WAVEFORM(SROW)
  IF SCOL = 6 THEN V = ENVS¯PW(SROW)

  RETURN

.SHOW¯CELL
'---------
  IF SROW=ROW AND SCOL = COL AND FFOCUS=0 THEN PRINT ËÅÙ¯ÒÅÖ¯ÏÎ;:ELSE PRINT ËÅÙ¯ÒÅÖ¯ÏÆÆ;

  IF COL = 0 THEN BEGIN
    PRINT V$;ËÅÙ¯ÔÁÂ;"’";
    RETURN
  BEND

  IF COL = 5 THEN BEGIN
    PRINT WNAME$(V);ËÅÙ¯ÔÁÂ;ËÅÙ¯ÒÅÖ¯ÏÆÆ;
    RETURN
  BEND

  ' ELSE
  PRINT V;ËÅÙ¯ÔÁÂ;ËÅÙ¯ÒÅÖ¯ÏÆÆ;
  RETURN


.GET¯USER¯INPUT¯FOR¯TABLE
'------------------------
  ' GET KEY A$
  GOSUB READ¯KEY¯LOOP
  IF A$ = ËÅÙ¯ÌÅÆÔ AND SCOL > 0 THEN SCOL = SCOL - 1
  IF A$ = ËÅÙ¯ÒÉÇÈÔ AND SCOL < 6 THEN SCOL = SCOL + 1
  IF A$ = ËÅÙ¯ÕÐ AND SROW > 0 THEN SROW = SROW - 1
  IF A$ = ËÅÙ¯ÄÏ×Î AND SROW < 9 THEN SROW = SROW + 1
  IF A$ = "+" OR A$="=" THEN DELTA=1 : GOSUB INCR¯VAL
  IF A$ = "-" THEN DELTA=1 : GOSUB DECR¯VAL
  IF A$ = ËÅÙ¯ÓÈÉÆÔ¯ÐÌÕÓ THEN DELTA=100 : GOSUB INCR¯VAL
  IF A$ = ËÅÙ¯ÓÈÉÆÔ¯ÍÉÎÕÓ THEN DELTA=100 : GOSUB DECR¯VAL
  IF A$ = ËÅÙ¯ÒÅÔÕÒÎ THEN A$ = "+" : GOSUB EDIT¯ENV¯FIELD
  IF A$ = ËÅÙ¯ÓÈÉÆÔ¯ÒÅÔÕÒÎ THEN A$ = "-" : GOSUB EDIT¯ENV¯FIELD

  IF A$ = ËÅÙ¯ÔÁÂ THEN FFOCUS = 1 : GOSUB GET¯USER¯INPUT¯FOR¯FILTERS

  GOSUB CHECK¯DURATION¯CHANGE
  GOSUB CHECK¯PIANO¯KEYS
  RETURN

.GET¯USER¯INPUT¯FOR¯FILTERS
'--------------------------
  DO WHILE 1
    GOSUB DRAW¯TABLE

    ' GET KEY A$
    GOSUB READ¯KEY¯LOOP

    IF A$ = ËÅÙ¯ÌÅÆÔ AND FSCOL > 0 THEN FSCOL = FSCOL - 1
    IF A$ = ËÅÙ¯ÒÉÇÈÔ AND FSCOL < 8 THEN FSCOL = FSCOL + 1
    IF A$ = ËÅÙ¯ÕÐ AND FSROW > 0 THEN FSROW = FSROW - 1
    IF A$ = ËÅÙ¯ÄÏ×Î AND FSROW < 10 THEN FSROW = FSROW + 1
    IF A$ = "+" OR A$="=" THEN DELTA=1 : GOSUB INCR¯FVAL
    IF A$ = "-" THEN DELTA=1 : GOSUB DECR¯FVAL
    IF A$ = ËÅÙ¯ÓÈÉÆÔ¯ÐÌÕÓ THEN DELTA = 100 : GOSUB INCR¯FVAL
    IF A$ = ËÅÙ¯ÓÈÉÆÔ¯ÍÉÎÕÓ THEN DELTA = 100 : GOSUB DECR¯FVAL

    IF A$ = " " THEN BEGIN
      IF FSEL = FSROW THEN FSEL = -1:ELSE FSEL = FSROW
      GOSUB APPLY¯SELECTED¯FILTER
    BEND

    IF A$ = ËÅÙ¯ÒÅÔÕÒÎ THEN GOSUB EDIT¯FILTER¯FIELD:GOSUB APPLY¯SELECTED¯FILTER

    IF A$ = ËÅÙ¯ÔÁ OR A$ = ËÅÙ¯ÍÅÇÁ¯Ñ THEN EXIT

    GOSUB CHECK¯DURATION¯CHANGE
    GOSUB CHECK¯PIANO¯KEYS
  LOOP
  FFOCUS = 0
  RETURN

.READ¯KEY¯LOOP
'-------------
  A$ = ""
  DO WHILE A$=""
    GET A$
    IF FSEL <> -1 THEN BEGIN
      GOSUB UPDATE¯SELECTED¯FILTER
    BEND
    IF PLYFLAG = 1 THEN BEGIN
      IF RPLAY(1) = 0 THEN GOSUB PARSE¯CURRENT¯SEQPTR
    BEND
  LOOP
  RETURN

.PARSE¯CURRENT¯SEQPTR
'--------------------
  K = SEQ¯CHUNK(PLYPTR)
  
  IF K >= 0 THEN BEGIN
    CHUNK¯IDX = K
    IF CHUNK¯RPT <= 0 THEN CHUNK¯RPT = SEQ¯EXTRA(PLYPTR)
    GOSUB PLAY¯CHUNK¯IDX
    SLEEP .1
    GOSUB DRAW¯SEQUENCE
  BEND
  IF K = ÃÍįÔÅÍÐÏ THEN BEGIN
    K = SEQ¯EXTRA(PLYPTR)
    TEMPO (K)
    TMPO% = K
  BEND
  IF K = ÃÍįÆÉÌÔÅÒ THEN BEGIN
    K = SEQ¯EXTRA(PLYPTR)
    FSROW = K
    FSEL = K
    GOSUB APPLY¯SELECTED¯FILTER
  BEND
  IF K = ÃÍįÅÃÈϯÍ1 THEN ECHO¯M = 1 : ECHO¯DELAY = 0
  IF K = ÃÍįÅÃÈϯÍ2 THEN ECHO¯M = 2 : ECHO¯DELAY = 0
  IF K = ÃÍįÅÃÈϯ  THEN ECHO¯B = 1 : ECHO¯DELAY = 0
  IF K = ÃÍįÅÃÈϯÏÆÆ THEN ECHO¯M = 0 : ECHO¯B = 0
  IF K = ÃÍįÅÃÈϯÓÚ THEN ECHO¯SZ = SEQ¯EXTRA(PLYPTR)
  IF K = ÃÍįÄÅÌÁÙ THEN ECHO¯DELAY = 1 : ECHO¯M = 0 : ECHO¯B = 0

  IF K = ÃÍįÖÏÌ THEN V = SEQ¯EXTRA(PLYPTR) : VOL V, V

  IF CHUNK¯RPT > 0 THEN CHUNK¯RPT = CHUNK¯RPT - 1

  IF CHUNK¯RPT <= 0 THEN PLYPTR = PLYPTR + 1

  IF K = ÃÍįÌÏÏÐ THEN PLYPTR = 0

  IF PLYPTR >= SEQCNT THEN PLYFLAG = 0 : PLYPTR = -1
  RETURN

.CHECK¯DURATION¯CHANGE
'---------------------
  FOR K = į×ÈÏÌÅ TO įÓÉØÔÅÅÎÔÈ
    IF A$ = DUR$(K, ÄËÅÙ) THEN SDUR = K
  NEXT K

  ' CHECK OCTAVE TOO
  IF A$ = ">" AND OCT < 6 THEN OCT = OCT + 1
  IF A$ = "<" AND OCT > 0 THEN OCT = OCT - 1

  RETURN


.UPDATE¯SELECTED¯FILTER
'----------------------
  IF FSEL = -1 THEN RETURN
  IF CURR¯DIR = ÄÉÒ¯ÎÏÎÅ THEN RETURN

  PRINT "";ËÅÙ¯ÔÁÂ;ËÅÙ¯ÔÁÂ;ËÅÙ¯ÔÁÂ;ËÅÙ¯ÔÁÂ;ËÅÙ¯ÔÁÂ;CHR$(27);"QCURR¯FREQ=";CURR¯FREQ;
  
  ' ÎÏÔÅ: ÃAN'T USE ÓÅÔÂÉÔ FOR ÓÉÄ REGISTERS AS THE REGS ARE WRITE-ONLY
  '       (ÓÅÔÂÉÔ WILL INTERNALLY NEED A READ PRIOR TO THE WRITE)

  ' ÂÕÇ? É COULDN'T DO ÐÏËÅ $Ä415 (IT BECAME 868691 = $Ä4153 ?!)
  WPOKE 54293, (CURR¯FREQ AND 7) + ((CURR¯FREQ >> 3) * 256)

  WPOKE 54357, (CURR¯FREQ AND 7) + ((CURR¯FREQ >> 3) * 256)

  IF CURR¯DIR = ÄÉÒ¯ÕÐ THEN BEGIN
    CURR¯FREQ = CURR¯FREQ + FILT¯SWEEP(FSEL)
    IF CURR¯FREQ > FILT¯FREQ(FSEL) THEN BEGIN
      CURR¯FREQ = FILT¯FREQ(FSEL)
      IF FILT¯DIR(FSEL) = ÄÉÒ¯ÏÓà THEN CURR¯DIR = ÄÉÒ¯ÄÏ×Î
      IF FILT¯DIR(FSEL) = ÄÉÒ¯ÕÐ THEN CURR¯FREQ = FILT¯MIN(FSEL)
    BEND
    RETURN
  BEND

  IF CURR¯DIR = ÄÉÒ¯ÄÏ×Î THEN BEGIN
    CURR¯FREQ = CURR¯FREQ - FILT¯SWEEP(FSEL)
    IF CURR¯FREQ < FILT¯MIN(FSEL) THEN BEGIN
      CURR¯FREQ = FILT¯MIN(FSEL)
      IF FILT¯DIR(FSEL) = ÄÉÒ¯ÏÓà THEN CURR¯DIR = ÄÉÒ¯ÕÐ
      IF FILT¯DIR(FSEL) = ÄÉÒ¯ÄÏ×Î THEN CURR¯FREQ = FILT¯FREQ(FSEL)
    BEND
    RETURN
  BEND

  RETURN


.APPLY¯SELECTED¯FILTER
'---------------------
  IF FSEL = -1 THEN RETURN

  CURR¯FREQ = FILT¯FREQ(FSEL)
  CURR¯DIR = ÄÉÒ¯ÎÏÎÅ
  IF   FILT¯DIR(FSEL) = ÄÉÒ¯ÕÐ _
    OR FILT¯DIR(FSEL) = ÄÉÒ¯ÏÓà THEN BEGIN
    CURR¯FREQ = FILT¯MIN(FSEL)
    CURR¯DIR = ÄÉÒ¯ÕÐ
  BEND
  IF FILT¯DIR(FSEL) = ÄÉÒ¯ÄÏ×Î THEN BEGIN
    CURR¯DIR = ÄÉÒ¯ÄÏ×Î
  BEND

  FILTER 1, FILT¯FREQ(FSEL), FILT¯LP(FSEL), _ 
         FILT¯BP(FSEL), FILT¯HP(FSEL), FILT¯RES(FSEL)
  FILTER 2, FILT¯FREQ(FSEL), FILT¯LP(FSEL), _ 
         FILT¯BP(FSEL), FILT¯HP(FSEL), FILT¯RES(FSEL)

  RETURN

.CHANGE¯ENV¯NAME
'---------------
  V$=""
  INPUT "NEW NAME: ",V$
  IF V$<>"" THEN ENVS¯NAME$(SROW) = V$
  RETURN

.EDIT¯ENV¯FIELD
'--------------
  IF SCOL = 0 THEN GOSUB CHANGE¯ENV¯NAME : RETURN
  IF SCOL = 6 THEN BEGIN
    V$=""
    INPUT "NEW VALUE: ",V$
    V = VAL(V$)
    IF V > 4095 THEN V = 4095
    IF V < 0 THEN V = 0
    ENVS¯PW(SROW) = V
    RETURN
  BEND

  IF A$="+" THEN DELTA=1 : GOSUB INCR¯VAL
  IF A$="-" THEN DELTA=1 : GOSUB DECR¯VAL
  RETURN

.EDIT¯FILTER¯FIELD
'-----------------
  IF FSCOL = 2 THEN V=FILT¯LP(FSROW):V=MOD(V+1,2):FILT¯LP(FSROW)=V:RETURN
  IF FSCOL = 3 THEN V=FILT¯BP(FSROW):V=MOD(V+1,2):FILT¯BP(FSROW)=V:RETURN
  IF FSCOL = 4 THEN V=FILT¯HP(FSROW):V=MOD(V+1,2):FILT¯HP(FSROW)=V:RETURN
  IF FSCOL = 6 THEN V=FILT¯DIR(FSROW):V=MOD(V+1,4):FILT¯DIR(FSROW)=V:RETURN

  V$=""
  INPUT "NEW VALUE: ",V$
  IF V$<>"" THEN BEGIN
    IF FSCOL = 0 THEN FILT¯NAME$(FSROW) = V$
    IF FSCOL = 1 THEN BEGIN
      V = VAL(V$)
      IF V > 2047 THEN V = 2047
      IF V < 0 THEN V = 0
      FILT¯FREQ(FSROW) = V
    BEND
    IF FSCOL = 5 THEN BEGIN
      V = VAL(V$)
      IF V > 15 THEN V = 15
      IF V < 0 THEN V = 0
      FILT¯RES(FSROW) = V
    BEND
    IF FSCOL = 6 THEN BEGIN
      V = VAL(V$)
      IF V > 3 THEN V = 3
      IF V < 0 THEN V = 0
      FILT¯DIR(FSROW) = V
    BEND
    IF FSCOL = 7 THEN BEGIN
      V = VAL(V$)
      IF V > 2047 THEN V = 2047
      IF V < 0 THEN V = 0
      FILT¯MIN(FSROW) = V
    BEND
    IF FSCOL = 8 THEN BEGIN
      V = VAL(V$)
      IF V > 2047 THEN V = 2047
      IF V < 0 THEN V = 0
      FILT¯SWEEP(FSROW) = V
    BEND
  BEND

.CHECK¯PIANO¯KEYS
'----------------
  ' APPLY FILTER
  PSTR$ = "X0"
  IF FSEL <> -1 THEN PSTR$ = "X1"

  ' DECIDE NOTE LENGTH
  PSTR$ = PSTR$ + DUR$(SDUR, ÄÃÈÁÒ)

  ' DECIDE OCTAVE
  PSTR$ = PSTR$ + "O" + STR$(OCT)

  ' WHICH NOTE TO PLAY
  FOR K = 0 TO 11
    IF A$ = KEYS¯IN$(K) THEN PSTR$ = PSTR$ + KEYS¯OUT$(K)
  NEXT K

  IF LEN(PSTR$)>0 THEN BEGIN
    PLAY "T"+STR$(SROW)+PSTR$
  BEND

  RETURN

.INCR¯VAL
'--------
  GOSUB GET¯VAL

  MAXV = 15
  IF SCOL = 5 THEN MAXV = 4
  IF SCOL = 6 THEN MAXV = 4095
  V = V + DELTA
  IF V > MAXV THEN V = MAXV
  GOSUB APPLY¯VAL
  RETURN


.DECR¯VAL
'--------
  GOSUB GET¯VAL

  V = V - DELTA
  IF V < 0 THEN V = 0
  GOSUB APPLY¯VAL
  RETURN


.INCR¯FVAL
'---------
  IF FSCOL = 1 THEN BEGIN
    V = FILT¯FREQ(FSROW) + DELTA
    IF V > 2047 THEN V = 2047
    FILT¯FREQ(FSROW) = V
  BEND

  IF FSCOL = 2 THEN FILT¯LP(FSROW) = 1
  IF FSCOL = 3 THEN FILT¯BP(FSROW) = 1
  IF FSCOL = 4 THEN FILT¯HP(FSROW) = 1

  IF FSCOL = 5 THEN BEGIN
    V = FILT¯RES(FSROW) + DELTA
    IF V > 15 THEN V = 15
    FILT¯RES(FSROW) = V
  BEND

  IF FSCOL=6 AND FILT¯DIR(FSROW) < 3 THEN FILT¯DIR(FSROW) = FILT¯DIR(FSROW) + 1

  IF FSCOL=7 AND FILT¯MIN(FSROW) < 2047 THEN BEGIN
    V = FILT¯MIN(FSROW) + DELTA
    IF V > 2047 THEN V = 2047
    FILT¯MIN(FSROW) = V
  BEND
    
  IF FSCOL=8 AND FILT¯SWEEP(FSROW) < 2047 THEN BEGIN
    V = FILT¯SWEEP(FSROW) + DELTA
    IF V > 2047 THEN V = 2047
    FILT¯SWEEP(FSROW) = V
  BEND

  GOSUB APPLY¯SELECTED¯FILTER
  RETURN


.DECR¯FVAL
'---------
  IF FSCOL = 1 THEN BEGIN
    V = FILT¯FREQ(FSROW) - DELTA
    IF V < 0 THEN V = 0
    FILT¯FREQ(FSROW) = V
  BEND

  IF FSCOL = 2 THEN FILT¯LP(FSROW) = 0
  IF FSCOL = 3 THEN FILT¯BP(FSROW) = 0
  IF FSCOL = 4 THEN FILT¯HP(FSROW) = 0

  IF FSCOL = 5 THEN BEGIN
    V = FILT¯RES(FSROW) - DELTA
    IF V < 0 THEN V = 0
    FILT¯RES(FSROW) = V
  BEND

  IF FSCOL=6 AND FILT¯DIR(FSROW) > 0 THEN FILT¯DIR(FSROW) = FILT¯DIR(FSROW) - 1

  IF FSCOL=7 AND FILT¯MIN(FSROW) > 0 THEN BEGIN
    V = FILT¯MIN(FSROW) - DELTA
    IF V < 0 THEN V = 0
    FILT¯MIN(FSROW) = V
  BEND

  IF FSCOL=8 AND FILT¯SWEEP(FSROW) > 0 THEN BEGIN
    V = FILT¯SWEEP(FSROW) - DELTA
    IF V < 0 THEN V = 0
    FILT¯SWEEP(FSROW) = V
  BEND

  GOSUB APPLY¯SELECTED¯FILTER
  RETURN


.APPLY¯VAL
'---------
  IF SCOL=0 THEN ENVS¯NAME$(SROW) = V$
  IF SCOL=1 THEN ENVS¯ATTACK(SROW) = V
  IF SCOL=2 THEN ENVS¯DECAY(SROW) = V
  IF SCOL=3 THEN ENVS¯SUSTAIN(SROW) = V
  IF SCOL=4 THEN ENVS¯RELEASE(SROW) = V
  IF SCOL=5 THEN ENVS¯WAVEFORM(SROW) = V
  IF SCOL=6 THEN ENVS¯PW(SROW) = V

  ROW = SROW
  GOSUB SET¯ENV
  RETURN


.SET¯ENV
'-------
  ENVELOPE ROW, ENVS¯ATTACK(ROW), ENVS¯DECAY(ROW), ENVS¯SUSTAIN(ROW), ENVS¯RELEASE(ROW), ENVS¯WAVEFORM(ROW), ENVS¯PW(ROW)
  RETURN

.RUNSTOP¯TRAPPER
'---------------
  IF ER=30 THEN RESUME  ' IGNORE RUN/STOP
  TRAP
  PRINT ERR$(ER);" ERROR"
  PRINT " IN LINE";EL
  KEY ON
  END

.CHUNK¯SEQUENCER
'---------------
  DO WHILE 1
    GOSUB DRAW¯SEQUENCE
    GOSUB GET¯USER¯INPUT¯FOR¯SEQUENCE

    IF A$ = ËÅÙ¯ÍÅÇÁ¯Ñ THEN EXIT
  LOOP
  RETURN

.DRAW¯SEQUENCE
'-------------
  PRINT "“SEQUENCE EDITOR"
  PRINT "---------------"
  PRINT "Á)DD É)NSERT Ä)ELETE, ÅDIT=ÒÔÎ, ÐLAYÁLL=ÓÈÆÔ+ÒÔÎ, ÐLAY=ÓÐÃ - SEQCNT = ";SEQCNT
  PRINT "Ã: EDIT ÃÍÄ, ÅÓÃ: STOP MUSIC, ÍÅÇÁ+Ñ: EXIT"
  PRINT " ÃMD            ÅXTRA"         
  PRINT " ---            -----"

  IF INT((SEQCNT-1)/43) > 1 AND (INT(SEQ¯OFFS/43)+1) < INT((SEQCNT-1)/43) THEN BEGIN
    'IF INT((SEQCNT-1) / 43) * 43 > SEQ¯OFFS THEN BEGIN
      CURSOR 75, 5:PRINT "--->"
    'BEND
  BEND
  IF SEQ¯OFFS > 0 THEN BEGIN
    CURSOR 70, 5:PRINT "<---"
  BEND

  K = SEQ¯OFFS
  DO WHILE K < SEQCNT
    IF K > (SEQ¯OFFS + 43 * 2 - 1) THEN K=SEQCNT:GOTO NXT

    IF (K-SEQ¯OFFS) >= 43 THEN CURSOR 40,6+(K-SEQ¯OFFS-43)
    IF PLYPTR = K THEN PRINT ">";:ELSE PRINT " ";

    S=0:GOSUB HIGHLIGHT¯SELECTED¯SEQ¯COLUMN

    ' CHUNK IS A SPECIAL ÃÍį*?
    IF SEQ¯CHUNK(K) < 0 AND ABS(SEQ¯CHUNK(K)) < ÃÍįÍÁØ THEN BEGIN
      V$ = SEQ¯CMDNAME$(ABS(SEQ¯CHUNK(K)))
      S = 10-LEN(V$)
      PRINT V$;
      DO WHILE S >= 0
        PRINT " ";
        S = S - 1
      LOOP
    BEND:ELSE BEGIN
      PRINT SEQ¯CHUNK(K);ËÅÙ¯ÔÁÂ;
    BEND

    S=1:GOSUB HIGHLIGHT¯SELECTED¯SEQ¯COLUMN
    HANDLED = 0
    IF SEQ¯CHUNK(K) = ÃÍįÆÉÌÔÅÒ THEN BEGIN
      HANDLED = 1
      IF SEQ¯EXTRA(K) = -1 THEN PRINT ËÅÙ¯ÔÁÂ;"<NONE>":ELSE BEGIN
        PRINT ËÅÙ¯ÔÁÂ;FILT¯NAME$(SEQ¯EXTRA(K))
      BEND
    BEND
    IF HANDLED=0 AND SEQ¯CHUNK(K) = ÃÍįÔÅÍÐÏ THEN BEGIN
      HANDLED = 1
      PRINT ËÅÙ¯ÔÁÂ;SEQ¯EXTRA(K)
    BEND
    ' ÅÌÓÅ
    IF HANDLED = 0 THEN BEGIN 
      PRINT ËÅÙ¯ÔÁÂ;SEQ¯EXTRA(K)
    BEND

    PRINT ËÅÙ¯ÒÅÖ¯ÏÆÆ;

.NXT
    K = K + 1
  LOOP
  
  RETURN

.HIGHLIGHT¯SELECTED¯SEQ¯COLUMN
'-----------------------------
  IF SEQPTR = K AND SSCOL=S THEN PRINT ËÅÙ¯ÒÅÖ¯ÏÎ;:ELSE PRINT ËÅÙ¯ÒÅÖ¯ÏÆÆ;
  RETURN

.GET¯USER¯INPUT¯FOR¯SEQUENCE
'---------------------------
  GOSUB READ¯KEY¯LOOP

  IF A$="A" THEN GOSUB ADD¯CHUNK¯TO¯SEQ
  IF A$="I" THEN GOSUB INSERT¯CHUNK¯TO¯SEQ
  ' IF A$="E" THEN GOSUB EDIT¯CHUNK¯SEQ
  IF A$="D" THEN GOSUB DELETE¯CHUNK¯SEQ

  IF A$=ËÅÙ¯ÕÐ AND SEQPTR > 0 THEN SEQPTR = SEQPTR - 1
  IF A$=ËÅÙ¯ÄÏ×Î AND SEQPTR < SEQCNT-1 THEN SEQPTR = SEQPTR + 1 
  IF A$=ËÅÙ¯ÌÅÆÔ THEN BEGIN
    IF SSCOL = 1 THEN BEGIN
      SSCOL = 0
    BEND:ELSE BEGIN
      IF (SEQPTR-43)>=0 THEN BEGIN
        SSCOL = 1
        SEQPTR = SEQPTR - 43
      BEND
    BEND
  BEND
  IF A$=ËÅÙ¯ÒÉÇÈÔ THEN BEGIN
    IF SSCOL = 0 THEN BEGIN
      SSCOL = 1
    BEND:ELSE BEGIN
      IF (SEQPTR+43) < SEQCNT THEN BEGIN
        SSCOL = 0
        SEQPTR = SEQPTR + 43
      BEND
    BEND
  BEND

  IF A$=ËÅÙ¯ÓÈÉÆÔ¯ÒÅÔÕÒÎ THEN BEGIN
    PLYPTR = 0
    PLYFLAG = 1
    CHUNK¯RPT = 0
    PLAY
    GOSUB SET¯ALL¯ENV
    TEMPO TMPO%
  BEND

  IF A$=ËÅÙ¯ÓÐÁÃÅ THEN BEGIN
    PLYPTR = SEQPTR
    PLYFLAG = 1
    CHUNK¯RPT = 0
    PLAY
    GOSUB SET¯ALL¯ENV
    TEMPO TMPO%
  BEND
  IF A$=ËÅÙ¯ÒÅÔÕÒÎ THEN GOSUB EDIT¯CHUNK¯CELL
  IF A$="C" THEN GOSUB EDIT¯CHUNK¯CMD
  IF A$=ËÅÙ¯ÅÓÃÁÐÅ THEN GOSUB STOP¯ALL¯MUSIC
  IF A$=ËÅÙ¯ÈÏÍÅ THEN SEQPTR = 0
  IF A$=ËÅÙ¯ÃÌÒ THEN SEQPTR = SEQCNT-1

  ' FINALLY, ADJUST SEQ¯OFFS IF NEEDBE
  IF (INT(SEQPTR / 43) * 43) < SEQ¯OFFS THEN SEQ¯OFFS = SEQ¯OFFS - 43
  IF (INT(SEQPTR / 43) * 43) > (SEQ¯OFFS+43) THEN SEQ¯OFFS = SEQ¯OFFS + 43

  RETURN

.STOP¯ALL¯MUSIC
'--------------
  PLYPTR = -1
  PLYFLAG = 0
  PLAY
  GOSUB SET¯ALL¯ENV
  TEMPO TMPO%
  GOSUB APPLY¯SELECTED¯FILTER
  RETURN

.DELETE¯CHUNK¯SEQ
'----------------
  IF SEQCNT = 0 THEN RETURN

  K = SEQPTR
  DO WHILE K < SEQCNT - 1
    SEQ¯CHUNK(K) = SEQ¯CHUNK(K + 1)
    SEQ¯EXTRA(K) = SEQ¯EXTRA(K + 1)
    K = K + 1
  LOOP

  SEQCNT = SEQCNT - 1

  IF SEQPTR = SEQCNT AND SEQPTR>0 THEN SEQPTR = SEQPTR - 1
  RETURN

.EDIT¯CHUNK¯SEQ
'--------------
  IF SEQCNT = 0 THEN RETURN

  PRINT ËÅÙ¯ÈÏÍÅ;ËÅÙ¯ÔÁÂ;ËÅÙ¯ÔÁÂ;ËÅÙ¯ÅÓÃÁÐÅ;"Q";
  V=0:INPUT "CHUNK#: ", V
  SEQ¯CHUNK(SEQPTR) = V

  PRINT ËÅÙ¯ÈÏÍÅ;ËÅÙ¯ÔÁÂ;ËÅÙ¯ÔÁÂ;ËÅÙ¯ÅÓÃÁÐÅ;"Q";
  V=-1:INPUT "EXTRA#: ", V
  SEQ¯EXTRA(SEQPTR) = V
  RETURN

.EDIT¯CHUNK¯CELL
'---------------
  IF SEQCNT = 0 THEN RETURN

  PRINT ËÅÙ¯ÈÏÍÅ;ËÅÙ¯ÔÁÂ;ËÅÙ¯ÔÁÂ;ËÅÙ¯ÅÓÃÁÐÅ;"Q";

  IF SSCOL = 0 THEN BEGIN
    V = SEQ¯CHUNK(SEQPTR)

    V1$ = STR$(V)
    IF LEFT$(V1$,1) = " " THEN V1$=MID$(V1$,2)

    PRINT "CHUNK#: ";ËÅÙ¯ÅÓÃÁÐÅ;"^";V1$;ËÅÙ¯ÅÓÃÁÐÅ;"_";
    INPUT "", V
    SEQ¯CHUNK(SEQPTR) = V
  BEND

  IF SSCOL = 1 THEN BEGIN
    V = SEQ¯EXTRA(SEQPTR)

    V1$ = STR$(V)
    IF LEFT$(V1$,1) = " " THEN V1$=MID$(V1$,2)

    PRINT "EXTRA#: ";ËÅÙ¯ÅÓÃÁÐÅ;"^";V1$;ËÅÙ¯ÅÓÃÁÐÅ;"_";
    INPUT "", V
    SEQ¯EXTRA(SEQPTR) = V
  BEND

  RETURN

.EDIT¯CHUNK¯CMD
'--------------
  V = -SEQ¯CHUNK(SEQPTR)
  PRINT ËÅÙ¯ÃÌÒ;
  FOR ROW = 1 TO ÃÍįÍÁØ - 1
    PRINT ROW;":"; SEQ¯CMDNAME$(ROW)
  NEXT ROW
  PRINT
  INPUT "CMD: ", V

  IF V > 0 THEN SEQ¯CHUNK(SEQPTR) = -V
  RETURN


.INSERT¯CHUNK¯TO¯SEQ
'-------------------
  SEQCNT = SEQCNT + 1

  ' MOVE ALL HIGHER CHUNK SEQUENCES UP ONE
  K = SEQCNT - 2
  DO WHILE K >= SEQPTR
    SEQ¯CHUNK(K+1) = SEQ¯CHUNK(K)
    SEQ¯EXTRA(K+1) = SEQ¯EXTRA(K)
    K = K - 1
  LOOP

  SEQ¯CHUNK(SEQPTR) = 0
  SEQ¯EXTRA(SEQPTR) = 0

  RETURN

.ADD¯CHUNK¯TO¯SEQ
'----------------
  SEQPTR = SEQCNT
  SEQCNT = SEQCNT + 1
  SEQ¯CHUNK(SEQPTR) = 0
  SEQ¯EXTRA(SEQPTR) = 0
  RETURN