collapseos/blk/589

: (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!
;