I remember the Vadic modem fondly. In the 1980's, on weekends I'd take home a terminal and a modem from work, and dial up the Tektronix Information Display Division's mainframe to play Rogue. However, I think that was 2400 not 1200.
Dave Wise ________________________________ From: Paul Koning via cctalk <[email protected]> Sent: Saturday, February 1, 2025 10:28 AM To: [email protected] <[email protected]> Cc: Paul Koning <[email protected]> Subject: [cctalk] Re: A baudy tale > On Jan 31, 2025, at 8:44 PM, Dennis Boone via cctalk <[email protected]> > wrote: > >> Those rack-mount Milgo units were built like battleships and very >> well regarded in the industry. My first "high-speed" modem was a >> Racal/Vadic 3451 that, IIRC, could do 2000 bps when talking to >> another 3451 using RV's proprietary protocol. > > Vadic had a variant 1200 baud system that wasn't compatible with 212, > too, as I recall. I remember Vadic, though vaguely. Incidentally, starting with the 212 modem and much more so with higher speed ones, using "baud" as a synonym for "bits per second" is incorrect. Baud, correctly used, is signaling units per second. For 103 and 202 modems which just use plain FSK, the two match. But the 212 uses QPSK, which means it does 1200 bits per second using 600 baud signaling. And the same, only more so, goes for the more complex modulation systems of faster modems. This applies to various modern high speed networks as well. Original Ethernet is one bit per baud. But that's not true for the higher speed ones. If you see a link that uses, say, QAM256 coding, you're looking at something that does 8 bits per baud (ignoring any ECC overhead, if the signaling scheme does such a thing). paul
