hhs@hou2h.UUCP (H.SHARP) (10/03/85)
A month ago or so I posted an article about a problem I had with a Hayes Smartmodem 2400. The problem was that when I ran the modem at 1200 bps (with my terminal set at 1200 bps), after the "CONNECT 1200" came up on the screen, I got garbage on the screen instead of the usual greeting. The garbage looked like a speed mismatch problem, but it wasn't. I have found a solution to the problem, but I am still not quite sure what the problem was. When I set up the options on the Hayes I chose the Bell mode instead of the CCITT mode. The ATB1 command options the modem to use BELL 212A at 1200 bps and the ATB0 command options the modem to use CCITT V.22. I have found that when I set the modem with either the ATB0 command or the ATB1 command I get garbage on the screen 3 out of 4 times (or worse). When I use the ATB command, the connection works fine. I could not find any detailed information on what exactly the ATB command does, but it is lumped together with the CCITT mode. If anyone has a suggestion as to what this means I would appreciate a reply. (The connection works fine when I use an AT&T 212, an AT&T 2224 and the integral modem on my AT&T - Teletype 4425 terminal.)
8332479@elecvax.eecs.unsw.oz (Bh Ting) (10/09/85)
There is nothing wrong with your modem. You said "... use Bell mode instead of CCITT mode..." , well, as far as I know, in the US, you can't use CCITT, as this is the standard used in Europe and Asia (mostly). Here, in Australia, I have a modem which has both Bell and CCITT modes, but I can only use the CCITT mode when connecting to local networks. If you decided to call someone overseas (directly) at his/her home, then CCITT mode will work (provided he/she is in Europe, Australia, Asia). When I find out how to cut down the long distance call phone bill, I'm going to use the Bell mode on my modem and logon to BBS and "stuff like that" in the US. I hope this explains your question. Regards, Bevan Ting (8332479:elecvax.OZ) (Greetings from Australia)