Configuring function keys for vt102

[Bill Campbell]

On Mon, Oct 15, 2007, Bob Rasmussen wrote:
>On Mon, 15 Oct 2007, Bill Campbell wrote:
>
>> I have found that the VT220 emulation works well with many dumb
>> terminals.  It is generally well supported, and has a full
>> selection of function keys.
>
>Except F5. Which has caused untold hassles.
>
>A standard VT220 has PF1 - PF4 over the num pad, and F1 - F20 across the 
>top. But F1 to F5 did local things within the terminal (such as setup), 
>and did not send codes to the server. Thus codes usable on the server 
>include PF1 - PF4 and F6 - F20. 

True enough, but I never ran into these problems with Wyse, and
other terminal's VT220 emulations.  Their function keys behaved
as one would expect.

I did get a bunch of DEC VT-220 terminals Really Cheap(tm) for a
class room, with genuine DEC keyboards which did have these
``features''.  Fortunately we were using these to teach Unix and
Linux courses where function keys were not critical.

Personally, I prefer mnemonic keystrokes (e.g. ctrl-I to insert,
ctrl-d to delete, etc.) as the original Scripsit program used,
and don't really like using function keys since they require
moving fingers from the keypad or home keys (I've often said
that WordPerfect would have been happy to use function keys for
all typing :-).

Programs depending on high function keys (F11->) often run into
problems with (a) terminals that don't have that many, or (b)
systems such as Apple's OS X that uses F9, F10, F11, and F12 for
system functions (yes you an redefine these functions, but IHMO
it would be better for programmers to avoid using them).

Bill
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