Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!mit-eddie!uw-beaver!ubc-vision!van-bc!sl From: sl@van-bc.UUCP (Stuart Lynne) Newsgroups: comp.sources.d,comp.terminals Subject: Re: VT100's keeping up at high baud rates Message-ID: <837@van-bc.UUCP> Date: Mon, 15-Jun-87 22:41:13 EDT Article-I.D.: van-bc.837 Posted: Mon Jun 15 22:41:13 1987 Date-Received: Sun, 21-Jun-87 06:10:39 EDT References: <1149@carthage.swatsun.UUCP> <8601@tekecs.TEK.COM> Reply-To: sl@van-bc.UUCP (Stuart Lynne) Organization: Public Access Network, Vancouver, BC. Lines: 42 Xref: mnetor comp.sources.d:849 comp.terminals:311 In article <4101@teddy.UUCP> jpn@teddy.UUCP (John P. Nelson) writes: >>> - Some (all?) PC/clones cannot keep up with speeds > 4800 baud in the VT100 >>> - terminal emulator >>> >>Heck, even the VT100 "emulation" inside a bona-fide _V_T_1_0_0 can't >>keep up at speeds of more than 4800 baud. >> > >I once did some benchmarking that you all might find interesting. I >wrote a program which did nothing but fill a 80x24 screen with blanks >several times, to time the terminal throughput (admittedly, without >scrolling, since that was not part of our requirement). The only >Anyway, true VT100's had a throughput just over 9600 baud. VT101's had >a throughput of only 4800!!!! VT220's could go a sustained 19200 baud! > The problem with VT100 is mainly with scrolling! From page 79 of the VT100 User Guide (2nd Edition, Jan '79): "Fill characters are required to keep the VT100 synchonized with the host computer when the XON/XOFF control codes are not used...." The following is gleaned from table C-1 on the same page: NEL, IND, LF, RI NEL, IND, LF,RI Speed Smooth Scolling Jump Scrolling 19200 384 60 9600 192 30 4800 96 15 2400 48 11 1200 24 7 300 6 1 NEL Next Line RI Reverse Index IND Index -- Stuart Lynne ihnp4!alberta!ubc-vision!van-bc!sl Vancouver,BC,604-937-7532