The null modem is present (without it, i guess the bitbanger wouldn't start) -

What is missing?

- i have not the faintest idea how baud rates are programmed into the 7201 (except there is an extra bitrate register at port $06 in 8088 I/O space with 2 half bytes for up and download rates ... $F means 19200, $E 9600 etc.).

- there are also 5 unemulated status and 4 control bits in 'comm_control_r' and 'comm_control_w'

Question is, how do i set individual port bits (DTR, RTS) or get the status of DSR, CTS, RI...?

The Rainbow documentation suggests the 808x CPU has direct control on these bits via 'comm_control_r' and 'comm_control_w'.

Thanks for any clues

Last edited by Bavarese; 07/03/16 07:26 AM.