Serial ports: How are the two Rx lines differentiated?

[Derek_Stewart]

Hi,

With regards to the Hermes source code, I would guess this is still with Laurence Reeves. Maybe if we ask nicely, he might release under a GPL licence like Minerva Source.

There is some extensions called SIMSER (see Dilwyn Site) by Hans Peter Reckenwald, which allows SER1/2 to have SRX, STX extensions added to the serial port. This allows Sernet to access SER1 or SER2 using the split serial clock rates.

I only managed to get reliable Sernet connection with an 8049 at 9600 baud, but since Hermes is a debugged version of the 8049 code, maybe a higher rate would be possible, I do not have a Hermes chip, so can not test it.

According to a recent email to Tony Firshman with regards Superhermes and Sernet, this is not possible as there is only one clock on the Superhermes so he say Sernet of split baud rates not possible.

I did wonder if SIMSER could be applied to the Superhermes SER3 port, but source code to SIMSER is not available. The code could be disassembled and modified for Superhermes SER3, which I am looking at now.