The Mythical \"X on a Dumb Terminal\" server, part 53

[valdis at sun.mcs.clarkson.edu]

Hmm. Maybe these wizards are cleverer than I, but I've been in this business
as either a student or a professional for close to a decade now, so I'll voice
my opinion... :-)

Somebody proposed that we use a downloadable 256-char font with appropriate
pixel definitions to cover all possible bit patters.

I've USED such a beast - it's called an IBM 3270 Programmable Symbol Set.

OK. So we're using 9x11 pixmaps.  (if not 9x11, then something else equally
sized 9x13, 11x15 - argument still holds).

Hmm. 99 pixels.  That gives us
a LOT of possible pixmaps - like 2**99 (each pixel can be on or off, count
in binary - we're all wizards here, right? :-)

Somehow I don't think we're gonna get it to fit.

And of course, that's the reason the IBM solution is ugly.  If you ever see
the 'coyboy hat' demo of Sas/graph, you can SEE where they cheated a bit
and MOVED THE LINES around so they could re-use an already defined character.
They only have like 3,000 graphics slots they can download.  And they STILL
have to cheat.

The biggest thing you can fit in a 256-char font and cover all bases is
if you have a 2x4 char font.  That gives you 8 pixels that need 2**8 = 256
different pixmaps for coverage. A 3x3 loses, as that's 9 pixels and 512 
pixmaps.  OK - all you OLD TIMERS out there - has ANYBODY ever seen a terminal
that gave you a ** two by four ** character matrix?? *AND* downloadable fonts?
*AND* didn't have a video generator that forced one blank pixel between chars
and two between rows like a lot do, so you have all-points-addressable?

I'm amazed that this discussion has gone this long without a reality check.

Personally, I'll wait for an X11 port to something a bit more powerful than
a terminal - like a Mac II.  Until then, I'll use 'screen' on my TVI 950
when I call from home.

				Valdis Kletnieks
				Sr. Systems Programmer
				Clarkson University