REM Convert Mac sound files to Amiga Format
REM David Q. King May 14, 1989

CLEAR ,80000
FILES
INPUT "Enter file name to convert";n$
OPEN n$ FOR INPUT AS #10
INPUT "Enter guestimate of samples per second for playback";freq%

ld&=LOF(10)          'length of sample

PRINT "file ";n$;" is ";ld&;" samples long."

OPEN n$+".8SVX" FOR OUTPUT AS #11
PRINT "output file is open as "n$".8SVX"

e$="FORM    8SVXVHDR                 NAME    "+n$+"BODY    "
REM fill in blanks in e$

formLength&=LEN(e$)-8+ld&
REM insert length of whole enchilada
CALL InsLong(4,formLength&)
REM insert length of name text
ln&=LEN(n$)
CALL InsLong(INSTR(e$,"NAME")+4,ln&)
REM insert length of body
CALL InsLong(INSTR(INSTR(e$,"NAME")+4+ln&,e$,"BODY")+4,ld&)
REM fill in fields in VHDR
v&=INSTR(e$,"VHDR")+4
CALL InsLong(v&,ld&)            'number of samples
CALL InsLong(v&+4, 0)         'repeatHiSamples = 0 for one shot
CALL InsLong(v&+8, 0)         'samplesPerHiCycle = 0 for one shot sample
CALL InsShort(v&+12, freq%)    'samples per second
CALL InsByte(v&+14, 1)        'ctOctave = 1 for one shot
CALL InsByte(v&+15, 0)        'no data compression
MID$(e$,v&+16,4)=MKS$(1)       'playback volume = 1.0 (maximum)

PRINT #11,e$;       'print header

PRINT "Converting..."
REM convert mac sample range to signed byte for amiga
n&=ld&
WHILE n&>0
  c&=1000
  IF n& > c& THEN    'set max size to read
    n&=n&-c&
  ELSE
    c&=n&
    n&=0
  END IF
  d$=INPUT$(c&,10)     'read a chunk'
  PRINT ".";
  
  FOR i&=1 TO c&
    x%=ASC(MID$(d$,i&,1))-128
    IF x% < 0 THEN x%=256+x% 
    MID$(d$,i&,1)=CHR$(x%)
  NEXT i&
  
  PRINT#11,d$;           'print a chunk

WEND

CLOSE(11)
PRINT "Done!"
END

REM GOSUB ShowD
END

SUB InsLong(p&, x&) STATIC
  MID$(e$,p&,4)=MKL$(x&)
END SUB

SUB InsShort(p&, x%) STATIC
   MID$(e$,p&,2)=MKI$(x%)
END SUB

SUB InsByte(p&, x%)  STATIC
   MID$(e$,p&,1)=CHR$(x%)
END SUB