For the SCC as well as the PICPAR, DCD is a hardware signal, so
you cannot reasonnably change the DCD algorithm with software only.
For PAR96 and SER12, it is indeed a software algorithm that can
be changed.
> I thought this was possible with _the_ DOS drivers, but perhaps unneaded
Only for SER12 and PAR96
> Do the radio drivers (scc/baycom/etc.) do some sort of recovery on
> recieved packets with wrong CRC ?
No. This does not make much sense anyway, as the redundancy introduced
by the CRC is much too low to be used for error correction.
You would end up with excessive undetected erroneos packets.
73s
Tom