Article View: comp.terminals
Article #2136Re: Mysterious VT100 behaviors
From: Bob Larson
Date: Mon, 05 Sep 1988 04:53
Date: Mon, 05 Sep 1988 04:53
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In article <6249@dasys1.UUCP> pechter@dasys1.UUCP (Bill Pechter) writes:
>There'a a number of undocumented "features" on the VT100 - some of which
>are real nasty microcode bugs in the firmware.
My favorites:
Infinite wait mode (display wait in the upper left corner until someone
hits the power switch): <esc>[?2;8y
Flashing background mode (also puts the terminal in local):
<esc>[?2;15y (I think)
Disabling flow control and sending scrolling region sequences at 2400
baud would drive the vt100 batty, sometimes doing such things as 24
copies of one line (the one with the cursor, the terminal still works!)
reverse scroling (linefeed means go up a line) etc. Usually the terminal
would reset itself eventually.
(If you didn't guess, the policy of not letting students read the manual
wasn't very efective, it led us to things we wouldn't have found otherwise.)
Some of the documented sequences were fun too: Tops-10 had a way to
type a file (in a public directory) from a not logged in terminal.
By putting a ^E in the end of the file and programming the answerback
buffer, an infinite loop displaying the file could be created.
Bob Larson Arpa: Blarson@Ecla.Usc.Edu blarson@skat.usc.edu
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!cs.utexas.edu!sm.unisys.com!oberon!skat.usc.edu!blarson From: blarson@skat.usc.edu (Bob Larson) Newsgroups: comp.terminals Subject: Re: Mysterious VT100 behaviors Keywords: vt100 undocumented behavior information wanted Message-ID: <11989@oberon.USC.EDU> Date: 5 Sep 88 04:53:20 GMT References: <13801@agate.BERKELEY.EDU> <6249@dasys1.UUCP> Sender: news@oberon.USC.EDU Reply-To: blarson@skat.usc.edu (Bob Larson) Organization: USC AIS, Los Angeles Lines: 29