nibble2char
*(pi1ppc->sc_inbstart) = ((nibble2char(nibble[1]) << 4) & 0xf0) |
(nibble2char(nibble[0]) & 0x0f);
*(atppc->sc_inbstart) = ((nibble2char(nibble[1]) << 4) & 0xf0) |
(nibble2char(nibble[0]) & 0x0f);