Intermittent Connectivity with US Modem

[codepoet80]

Discussed at length on AssemblerGames, but adding here for tracking. There seems to be timing issues when using a US Dreamcast modem that reduce the odds of a successful connection to about 1 in 3. Some games (Maximum Pool, 4x4 Evo, Starlancer) won't accept even a successful connection, and hang up immediately after connection (rage quit). Logs attached.

BadGoodConnectionLog.txt

Starlancer-RageQuit.txt

[codepoet80]

Resolved by expanding the response detection evaluation to include partial strings: "ER" instead of "ERROR" or "CO" instead of "CONNECT" since random new-line characters were seen in modem responses and screwing up the string comparison.

[Kazade]

This is still an issue. 0.98 had code to strip newlines and buffered the output - I don't suppose you could print out the buffer variable when the timeout exception is thrown?

[codepoet80]

I'm not sure exactly which is the buffer variable, but I modified the end of send_command, thusly:

if (datetime.now() - start).total_seconds() > timeout:
logger.info("Last string in buffer...")
logger.info(line)
raise IOError("There was a timeout while waiting for a response from the modem")

And get this output when a connection fails...

Last string in buffer...
ATACO
Something went wrong...
Traceback (most recent call last):
File "./dreampi.py", line 368, in main
return process()
File "./dreampi.py", line 345, in process
modem.answer()
File "./dreampi.py", line 247, in answer
self.send_command("ATA")
File "./dreampi.py", line 278, in send_command
raise IOError("There was a timeout while waiting for a response from the modem")
IOError: There was a timeout while waiting for a response from the modem

Another attempt looked like this:

Last string in buffer...
ATAC
Something went wrong...
Traceback (most recent call last):
File "./dreampi.py", line 368, in main
return process()
File "./dreampi.py", line 345, in process
modem.answer()
File "./dreampi.py", line 247, in answer
self.send_command("ATA")
File "./dreampi.py", line 278, in send_command
raise IOError("There was a timeout while waiting for a response from the modem")
IOError: There was a timeout while waiting for a response from the modem