collapseos/arch/z80/rc2014/blk/609

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: (key)
( inc then fetch )
[ SIOR> LITN ] C@ 1+ [ SIO_BUFSZ 1- LITN ] AND
( As long as R> == W>-1, it means that buffer is empty )
BEGIN DUP [ SIOW> LITN ] C@ = NOT UNTIL
DUP [ SIO( LITN ] @ + C@ ( ridx c )
SWAP [ SIOR> LITN ] C! ( c )
;
: (emit)
( As long at CTL bit 2 is low, we are transmitting. wait )
BEGIN [ SIO_ACTL LITN ] PC@ 0x04 AND UNTIL
( The way is clear, go! )
[ SIO_ADATA LITN ] PC!
;