edward@ucbarpa.Berkeley.EDU (Edward Wang) (08/12/89)
Are there terminals out there with something like a "programmed string" feature: escape sequences that can be programmed on-the-fly to expand into strings of displayed characters? Somewhat like the reverse of programmed function keys. The programming must be done by other escape sequences, not from the keyboard. I've been playing with data compression using a simple model like this, going from a Unix machine to my own terminal emulator (on an Apple II). I'm just wondering whether there are commercial terminals that can support it. By the way, I get factor-of-two compression (4800 baud on a 2400 baud line) on a good day, and almost always more than 1.5.
loverso@Xylogics.COM (John Robert LoVerso) (08/15/89)
In article <30582@ucbvax.BERKELEY.EDU> Edward Wang asks about terminals
that support text compression by pre-programming common strings.
Someone at CMU did exactly this with some custon Ann Arbor ROMs, ~8 years
ago. There was a tech report or two published about it. I'll see if I can
dig up references.
What I remember from what I was told about it, a pre-compiled list of common
text strings was derived from internal CMU bulletin boards (and/or possibly
USENET). This was part of the ROMs in each terminal. Additionally, there
was escape sequences or the like to redefine common strings. I think the
strings were asked for by the 128-255 codes. Finally, I think a line disc
was introduced that knew how to compress text, but the same feature could
easily be placed into a `screen'-like program, etc.
John