Question about modems
alexandre.tabajara at gmail.com
Wed Nov 13 07:47:03 CST 2019
Jim, its a long time I don't use it, but I've used other configurations
beyond 8N1 and I remember when you put the modem in 7E1 it mirrored the
configuration of the other side. If you had a vax with a 2400 7E1 port,
you gotta have in the terminal 2400 7E1
So, you gotta match the configuration of the other side
Hope that helps!
Em 13/11/2019 04:25, Jim Brain via cctalk escreveu:
> I am the author of tcpser, a UNIX/Windows program that emulates a Hayes
> Some time ago, Chris Osborn (FozzTexx) forked a copy of my project to
> fix some bugs and he also added in some parity code, which looks to
> strip parity from the incoming serial connection (in the case that the
> serial port is set as 8N1 and the computer attached to it sends in 7E1
> or similar.
> I am working to merge in all of his changes into the mainline codebase,
> but I am unclear on prpper Hayes behavior. His Readme says:
> "I also made the modem routines automatically detect parity and ignore
> it in AT commands and print out modem responses in matching
> parity. Parity is *not* stripped when sending data over the
> connection, which is how a real modem behaves. This may or may not be
> what you want. Some servers will expect an 8 bit connection and may
> not work."
> Did Hayes modem really do that? I thought most later modems self
> detected parity and speed and thus would have switched both the comm on
> the serial port and the data sent to the other side in the same parity
> (if the terminal was 7E1, the modem would configure as 7E1 and send 7
> bit data to the other side.
> But, maybe real modems did as Chris notes. Anyone have guidance on
> this? The goal of tcpser is to emulate a Hayes modem as much as
> possible, but I never really thought about mismatched parity on the
> RS232 line and how to deal with it.
More information about the cctech