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Thread ID: 37740 2003-09-16 23:59:00 Looking for obsolete modem Morse (4575) Press F1
Post ID Timestamp Content User
175817 2003-09-16 23:59:00 Has anyone ever used or heard of an obsolete modem by Tandy (DCM series) or other manufacturer which uses the 300 baud Bell 103 standard? It has manually selectable answer and originate tones. I need to find one of these to facilitate dial-up telegraphy but don't want to waste time advertising if they were never used in New Zealand. Morse (4575)
175818 2003-09-17 00:28:00 I would think they would have been around, but there wouldn't have been many of them and that was a long time ago.....
robo.
robo (205)
175819 2003-09-17 03:49:00 I used the 300 baud modems many years ago (man they were fast, compared to 50 baud)
They also had a 300/1200 baud mode.
They weren't Tandy but were locally made.

So that type of modem was available here in the '80s

Would not have a clue as to any working ones remaining.
godfather (25)
175820 2003-09-17 06:34:00 You might not have to hunt far for an obsolete modem. Try a modern one. :D There is a Hayes AT code F1, which sets a modem to "V21 or Bell 103" mode. It might not work on some of the most modern ones, (especially Winmodems ?) but any reasonably "old" like a 14/28/33.6 kbps one will probably work. Look especially for ISA or very specially for external modems. You might be looking at external modems anyway.

Backwards compatibilitty is a wonderful thing. B-)
Graham L (2)
175821 2003-09-18 05:39:00 That "F1" seems to be a bit of wrong information from the Internet. :D "B1" looks much better. I had a look at a few modem manuals at home, and it looks as if you've got a pretty good chance.

B0 selects CCIT, B1 selects Bell 103 tones if 300 baud is selected. Special register s14 looks to be the one for answer/originate (though one book says the bit switches "intuitively" ... if the modem answers, it goes to answer; if it dials out it goes to originate. The modems which look to be OK are a Genius 56k one, a no-name V32 bis, V 32 model , a 3Com PC card combination ethernet/33.6k modem card (!:D). One book for a USRobotics Sportster didn't look encouraging. That's not a bad ratio for the books I could find in a quick search.
Graham L (2)
175822 2003-11-06 07:30:00 Graham - Thanks a heap for your info on obsolete modem I requested. Sorry have taken so long to get back to you but I lost my username and code word info so couldnt get back into the program for a while - its all very confusing to me anyway. I posted the original request under "Morse" and have reregistered under "Amorse" so I hope this reply finds you. Thanks again and best wishes. - Maurie Challinor Amorse (4576)
175823 2003-11-06 07:56:00 If it was me I'd connect an External Modem on Com2 and have a very close look at AT commands. Elephant (599)
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