Changes
/* Complete keyboard scanning routine */
keyscan di ;1 ##%%## C P C VERSION ##%%##
xor a ;1
ld hl,keymap ;3
ld bc,#f782 ;3
out (c),c ;4
ld bc,#f40e ;3
out (c),c ;4
ld e,b ;1
ld bc,#f6c0 ;3
out (c),c ;4
out (c),a ;4
sub c ;1 a=#40 (-#C0)
ld bc,#f792 ;3
out (c),c ;4
loop ld b,d ;1
out (c),a ;4 select line
ld bc,#f782 ;3
out (c),c ;4
ei ;1 (+8 = 209 208 microseconds)
ret
</pre>
