The 115,200 is a side affect of the way the baud rate divisor worked on the original 8250 UART. It is the baud rate obtained with the minimum divisor. Bob Ammerman RAm Systems ----- Original Message ----- From: "John J. McDonough" To: Sent: Tuesday, January 20, 2004 7:31 PM Subject: Re: [EE:] Why don't baud rates just double? > There is a little history impairment going on here methinks. > > The "standard" baud rates: > 38,400 > 19,200 > 9,600 > 4,800 > 2,400 > 1,200 > 600 > 300 > > were intended for baseband communication and are harmonically related as you > observed. In the early days, modems also matched these "standard" baud > rates. > > However, modem makers found that by using different encoding techniques, > they could get speeds greater than 9,600, but not always quite up to the > next standard frequency. So we had 14.4, 28.8, 33.6, 48.4 and 57.6 (and > probably a few others). These were derived from the technology, rather than > from any sort of standard. > > I believe 115.2 was simply a way of getting data into the PC faster than the > modem could move it across the landline ... I don't believe it is/was ever > used much for out of the box communications. > > 72/73 de WB8RCR http://www.qsl.net/wb8rcr > didileydadidah QRP-L #1446 Code Warriors #35 > > > ----- Original Message ----- > From: "James Newton, Host" > To: > Sent: Tuesday, January 20, 2004 7:17 PM > Subject: [EE] Why don't baud rates just double? > > > > Why is each higher baud rate twice as fast until 14.4K which is only 1.5 > > times faster than 9600? > > > > 115,200 > > 57,600 > > 28,800 > > 14,400 > > ? > > 9,600 > > 4,800 > > 2,400 > > 1,200 > > 600 > > 300 > > > > --- > > James Newton: PICList webmaster/Admin > > mailto:jamesnewton@piclist.com 1-619-652-0593 phone > > http://www.piclist.com/member/JMN-EFP-786 > > PIC/PICList FAQ: http://www.piclist.com > > > > -- > > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body > > > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu