Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site cornell.UUCP Path: utzoo!utcsri!ubc-vision!uw-beaver!cornell!jqj From: jqj@cornell.UUCP (J Q Johnson) Newsgroups: net.dcom,net.micro,net.unix-wizards Subject: interactive (host=>PC) data compression wanted Message-ID: <741@cornell.UUCP> Date: Thu, 26-Sep-85 05:49:28 EDT Article-I.D.: cornell.741 Posted: Thu Sep 26 05:49:28 1985 Date-Received: Fri, 27-Sep-85 13:35:13 EDT Reply-To: jqj@cornell.UUCP (J Q Johnson) Followup-To: net.dcom Organization: Cornell Univ. CS Dept. Lines: 23 People using a terminal emulator on home computer with a modem soon find that 1200b or 2400b isn't all that fast. In principal, effective data rates for typical interactive terminal sessions could be improved by at least a factor of 2 or 3 using data compression techniques. Does anyone have software for such host=>terminal data compression? Easy static techniques exist for 20% to 50% improvements; can we do better? Note that in addition to being self-synchronizing or reliable (to cope with modem transmission failures) any such technique must not be too costly to either encode or decode. Note also that various vendors have quite efficent proprietary implementations. My particular environment is a 4.xBSD host and an ATT 3b2 (sys V) or IBM PC (running DOS or Xenix) client, talking at 1200b asynch 7 bit with XON/XOFF. Ideally I'd like public domain code that supports at least one of these environments. Failing that, pointers to algorithms or publicly available implementations for other environments would also be appreciated. Given sufficient feedback, I will of course summarize. cornell!jqj UUCP jqj@cornell.arpa Internet Brought to you by Super Global Mega Corp .com