Question about modems

Jim Brain brain at
Fri Nov 15 20:03:38 CST 2019

On 11/15/2019 5:18 PM, Chris Osborn via cctalk wrote:
> On Nov 15, 2019, at 1:54 PM, alan--- via cctalk <cctalk at> wrote:
>> MCU should set receive line coding to 8,N,1.  When in command mode, you don't care about parity
> Actually it's in command mode that you *do* care about parity, which is why I added the parity detection in the first place. Without the parity detection there's no way for the modem to send back the command responses with the correct parity. That made it cumbersome to use tcpser when using terminals or communications software that insist on using even/odd/mark parity and would drop any characters that had the wrong parity.

And, as I noted to Chris, I think it actually makes sense to convert all 
the time, so that a 7E1 device that is trying to connect to the Internet 
can do so with a minimum of hassle.  If parity is stripped on both sides 
(C64 to tcpser to Internet to tcpser to 64, for example) and replaced 
when needed for the local classic machine, I think that's the best scenario.


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