[HN Gopher] VT220 Built-in Glyphs (2006)
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VT220 Built-in Glyphs (2006)
Author : rbanffy
Score : 42 points
Date : 2021-06-01 14:32 UTC (8 hours ago)
(HTM) web link (www.vt100.net)
(TXT) w3m dump (www.vt100.net)
| wanderingjew wrote:
| This is a great trick, but it's only really useful if you're
| using a CRT or are on a very memory-constrained platform where
| you can't store a separate 'bold' font.
|
| I've implemented it here
| https://twitter.com/ViolenceWorks/status/1387519297262477312 and
| barring the exception of fiddling around with dotclocks and such,
| it would be far simpler to have a different 'bold' font. Of
| course, if you're using a CRT doing this is as easy as 'keep the
| gun on a bit longer if it's bold'.
|
| This is one of the rare cases where you really get to see the
| relation of a CRT with the thought of, 'a technology is only
| perfected after it has been rendered obsolete.'
| rbanffy wrote:
| > 'a technology is only perfected after it has been rendered
| obsolete.'
|
| It's easier when it stops moving.
| zozbot234 wrote:
| The horizontal pixel doubling as mentioned in the article was a
| common trick on home computer character sets, which helped cope
| with the poor horizontal resolution of color TV signals. Though
| the default font in PC text mode also has a similar appearance
| which seems a bit harder to explain. Perhaps it was a pure
| readability concern there, similar to the thick vertical strokes
| in many printed typefaces.
| masswerk wrote:
| Mind that IBM 5150 had still a TV output (as well as a cassette
| port and BASIC in ROM), much like the home computers of the
| time.
| rbanffy wrote:
| Still, they could use something derived from the 3270's more
| elegant font...
|
| IIRC, you could use dip switches to select different
| character ROMs. My CGA had a horrible font with single pixel
| wide stems.
| GekkePrutser wrote:
| I think all CGAs did have that font by default because CGA
| just had just poor resolution that they didn't have space
| for better characters.
|
| Most CGA adapters switched to MDA or Hercules mode when
| displaying text, which offered much better rendering. But
| if you needed to mix graphics and text this didn't work. So
| you got stuck with the piss-poor 320x200. And the two
| hideous colour palettes.
|
| I never understood how anyone could design that and think
| it was a good idea or something.
| masswerk wrote:
| The PC (5150) wasn't a "real" IBM design, but was developed
| externally. Even more so, IBM was quite cautious to not put
| their more valuable assets on risk by this "small" office
| machine (a strategy, which eventually came to nothing with
| the advent of the i386 generation). So there wasn't much
| "trickle-down" and the 3270 stuff was still dedicated to
| "genuine" IBM assets. You couldn't even run a 3270 terminal
| emulation. This required an expensive extra card or later a
| special XT model. - Just consider this: the 5150 was
| actually some sort of plan B, where plan A would have been
| to acquire Atari and sell (a possible somewhat improved
| version of) the Atari 800 as the IBM PC (there are photos
| of prototypes for the repackaged design by Bill Lowe [1]).
| Which may also shed some light on what the original specs
| for the 5150 may have looked like.
|
| [1] https://twitter.com/yesterbits/status/97511900453167923
| 2/pho...
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(page generated 2021-06-01 23:01 UTC)