Content originally posted in LPCWare by starblue on Sat Aug 01 11:48:50 MST 2015
Quote: IanB
Whose idea were all these strange baud rates?
It started with 300 baud (at least that is the lowest I encountered in the early eighties, ignoring 1200/75 for BTX), on an acoustic coupler.
Then you start doubling it: 600, 1200, 2400, 4800, 9600, 19200, 38400 were all common baud rates for modems.
The ISDN phone system sends 8K samples of 8 bits per second, so it maxes out at 64Kbit/s, so you can't get 76800 over a phone line. You can't get 64Kbit/s either on an analog phone because of the digital-to-analog-to-digital conversion. But you can get 57600 = 3 * 19200 if the line is good.
Continue doubling: 115200, ...