DECLARE SUB sboff ()
DECLARE SUB sbsetup ()
DECLARE SUB setupnotetable ()
DECLARE SUB sbnote (ch%, NOTE%, n%)
DECLARE SUB sbout (r%, d%)
DECLARE SUB writeaddr (b%)
DECLARE SUB writedata (b%)
DECLARE SUB resetsb ()
DIM keytable AS SHARED STRING
DIM notetable(0 TO 50) AS SHARED INTEGER
keytable$ = "                         Q2W3ER5T6Y7UI9O0P[=]"
setupnotetable
SCREEN 0
WIDTH 80, 25
CLS
COLOR 10
PRINT "Simple adlib piano"
COLOR 12
PRINT "  C  C#  D  D#  E  F  F#  G  G#  A  A#  B  C    Exit"
PRINT
PRINT "  Q   2  W  3   E  R  5   T  6   Y   7  U  I     X"
resetsb
sbout 1, &H10                   'THAT IS WHAT I MISSED
sbsetup
DO
        pbin$ = UCASE$(INPUT$(1))
        r% = notetable%(INSTR(keytable$, pbin$))
        sbnote 1, r%, 1
LOOP UNTIL pbin$ = "X"
sboff
resetsb

SUB resetsb
FOR i% = 1 TO &HF5
        writeaddr (i%)
        writedata (0)
NEXT i%
END SUB

SUB sbnote (ch%, NOTE%, n%)

IF NOTE% > 512 THEN F% = 2 ELSE F% = 1
IF NOTE% > 768 THEN F% = 3
sbout &HA0 + ch%, NOTE% AND 1279
sbout &HB0 + ch%, (&H20 * n%) OR &H10 OR F%

END SUB

SUB sboff
writeaddr (&HB0)
writedata (&H11)
END SUB

SUB sbout (r%, d%)
writeaddr (r%)
writedata (d%)
END SUB

SUB sbsetup
sbout &H20, 1
sbout &H40, &H10
sbout &H60, &HF0
sbout &H80, &H77
sbout &HA0, &H98
sbout &H23, 1
sbout &H43, 0
sbout &H63, &HF0
sbout &H83, &H77
sbout &HB0, 0
END SUB

SUB setupnotetable
notetable%(0) = 0
notetable%(26) = &H157  'C
notetable%(27) = &H16B  'C#
notetable%(28) = &H181  'D
notetable%(29) = &H198  'D#
notetable%(30) = &H1B0  'E
notetable%(31) = &H1CA  'F
notetable%(32) = &H1E5  'F#
notetable%(33) = &H202  'G
notetable%(34) = &H220  'G#
notetable%(35) = &H241  'A
notetable%(36) = &H263 'A#
notetable%(37) = &H287 'B
notetable%(38) = &H2AE 'c
notetable%(39) = &H2D6 'c#
notetable%(40) = &H302 'd
notetable%(41) = &H330 'd#
notetable%(42) = &H360 'e
notetable%(43) = &H394 'f
notetable%(44) = &H3CA 'f#
notetable%(45) = &H404 'g
notetable%(46) = &H440 'g#
notetable%(47) = &H482 'a
notetable%(48) = &H4C6 'a#
notetable%(49) = &H50E 'b
notetable%(50) = &H55C 'C
END SUB

SUB writeaddr (b%)
OUT &H388, b%
'FOR a% = 1 TO 6
        x% = INP(&H388)
'NEXT a%
END SUB

SUB writedata (b%)
OUT &H389, b%
'FOR a% = 1 TO &H34
        x% = INP(&H389)
'NEXT a%
END SUB