GEOF@mit-xx@sri-unix.UUCP (08/11/83)
From: Geoffrey H. Cooper <GEOF@mit-xx>
I too have been somewhat amused at the number of messages that request
termcap entries for pieces of hardware (...does anyone have a termcap
entry for a black telephone with a white receiver...). Since ...jdi's
message about Camelon didn't quite explain why these queries make no
sense, I thought I'd try.
A termcap entry is a description of a terminal's software characteristics.
It specifies what codes the computer should send to do interesting things
like clear the screen, move the cursor, and so on. When you buy a hardware
terminal like a vt-52 or a h19 or an adm-3a, the hardware and software
characteristics of the machine are linked, so that one name is sufficient to
describe both.
When you buy a personal computer, and then hook a modem to it to use it as
a terminal, you need some specialized software to make the whole thing
work. Sometimes this software just makes the computer act as if it were some
popular computer terminal, such as a vt52, in which case, your computer
can be aptly described to the foreign computer as a vt52.
More commonly, the software (the so-called terminal emulation package)
makes your computer look something like some existing terminal, but not
exactly. To get things like EMACS and ROGUE to work with your computer
(if you use berkeley unix) you then need to have a custom TERMCAP which
describes just what your computer and software combination looks like.
When you say something like "does anyone have a termcap entry for a TRS-80
COLOR COMPUTER...?" you are asking a non-question. The statement doesn't
even type-check: 'termcap' represents the sofware interface and 'TRS-80'
represents the hardware. Given enough hacking, you can make your TRS-80
work with ANY termcap entry.
Next time you need a termcap entry, and you think someone has it over the
net, just fill in the blanks:
"Does anyone have a TERMCAP entry for a _____________(hardware)
computer running the terminal emulation software _______________ ?"
- Geof
-------stepp@uiuccsb.UUCP (08/17/83)
#R:sri-arpa:-411700:uiuccsb:4400007:000:7 uiuccsb!stepp Aug 16 09:10:00 1983 Bravo!