gary@brb.isnet.inmos.co.uk (06/16/90)
In article <2878@syma.sussex.ac.uk>, grahamt@syma.sussex.ac.uk (Graham Thomas) writes: > There are several commercial programs which allow you to call up > services transmitting at 1200/75 bits per second (V23). Two of them are > Fastcom (the ST version of Vicom for the PC) and K-Comm. They also > support viewdata services (videotex services operating to the Prestel > standard). However, they are not PD/Shareware, and are not particularly > wonderful programs either. I can't remember exactly where I heard this, but the above program recieves at 1200 baud using the normal UART mechanism. However to transmit at the slower 75 baud rate, the software makes use of ability to set the Transmit Out pin to the appropriate state (by forcing a Break?). I assume another timer is setup to interrupt at an appropriate rate for 75 baud, and that the interrupt routine either sets or resets the TX Out pin for each of the start, data, and stop bits (one transition per interrupt). --Gary ============================================================================ Gary Morton Inmos Ltd, Aztec West, Bristol | EMail(UK) ----------| +44 454 616616 X520 |------------| gary@brb.isnet.inmos.co.uk The opinions above are my personal views | EMail(ROW) and may not reflect Inmos policy. | gary@brb.isnet.inmos.com ============================================================================