
Raster CRT Typography According to DEC - fanf2
https://www.masswerk.at/nowgobang/2019/dec-crt-typography
======
13of40
Reminds me a bit of a weekend project I did a few years back: When I was about
6, my dad went out and bought what would be the family computer for half a
decade, a TI-99/4a. The thing that stuck in my craw was that even though Apple
and Commodore had mastered the lowercase Latin font, the lowercase letters on
the TI were just tiny uppercase ones. So flash forward 25 years or so, and I'd
downloaded a TI-99 emulator to play with, and decided to see if I could put an
Apple II font on it. It was relatively easy to find the font in the ROM, and I
found a donor font through Google. Kludged them together, and it worked
beautifully. Lowercase letters on a TI-99! No idea WTF they were thinking with
the original font.

~~~
ChuckMcM
I don't know either, however TI at the time also produced the "Silent 700"
terminal series and it had the same font (all essentially upper case
characters just some larger and some smaller.

Perhaps it was an early example of the DRY mantra being applied incorrectly.

~~~
theoh
[https://en.wikipedia.org/wiki/Small_caps](https://en.wikipedia.org/wiki/Small_caps)

~~~
theoh
That was an unobjectionable comment, so I guess the downvotes are a stimulus
to try to get me to write more. The Wikipedia page for the TI-99 mentions the
"small capitals" but does _not_ link to the page I linked to. So some people,
at least, who read that page won't get the reference to the typographic
tradition (if that's what it is).

A larger issue is the idea that, by choosing a small caps style for their
font, TI were acting inexplicably or irrationally. It is worrying but not
surprising that the HN crowd finds it disturbing when a company makes a
creative decision that doesn't have a clear business case behind it, while
being completely innocuous, and which potentially could have helped to
differentiate their products. It's the typical negative engineer stereotype
coming through: "No imagination or creativity allowed, except if it's to solve
a specific problem".

~~~
wtallis
That Wikipedia page you linked to explains that small caps are used almost
exclusively to emphasize or distinguish text from text set using the usual mix
of uppercase and lowercase letters. So pointing out that small caps are a
well-established typographical practice does nothing to explain what TI was
thinking by including small caps but not lowercase. And no matter how
innocuous you consider it, it is clear that the decision strikes many users as
odd, and that it comes across as something of an unattractive technological
limitation, akin to the then-recent systems that only supported uppercase.

~~~
theoh
It's slightly complicated, but the smaller caps of "small caps" _are_ the
lower case. As Wikipedia says, setting text in small caps is "technically not
a case-transformation". In those days it would not be surprising that a system
would only have one font.

I don't know about the Silent 700's font, but it looks to me like this
probably wasn't a mistaken case of the DRY principle: after all, the TI-99's
lower case letters are still stored as separate bitmaps (they are reproduced
in an image here: [http://electrickeet.com/line-
itfont.html](http://electrickeet.com/line-itfont.html)).

So it is clear, at least, that they had the storage for lower case, and for
whatever reason decided to go with a small caps font. It isn't a result of a
simple limitation that they hacked around by scaling bitmaps or something like
that. I wouldn't like to speculate about what fraction of users found it odd
at the time.

------
avian
Interesting post. From my work on 1980s micros that used CRT TVs for display,
the phosphor response described here seems to be a bit oversimplified.

In my purely subjective experience, rise time seems to be shorter than fall
time - pixels will usually be visibly blurred on the trailing (right) edge,
but sharper on the leading (left) edge. Another thing I noticed is that a
longer horizontal row of pixels will leave a longer decay on the trailing edge
than a single pixel. For example, the Ts will usually have their horizontal
line visibly stretched on the trailing edge, even when the vertical line
seemed sharp.

Of course, purpose-built terminals might have used different phosphors than
cheap TVs of the time. It might also have to do with video amp bandwidth, or
something else electrical.

~~~
jepler
Without disagreeing with you, the diagrams from the linked page are pretty
much reproductions of the ones from an official VT100 technical manual,
[https://vt100.net/docs/vt100-tm/](https://vt100.net/docs/vt100-tm/)

It appears to me that the rise/fall graphs are just graphs of ideal RC
networks, while the whole true CRT system will have lots of other factors such
as inductance going on.

When it comes to comparing what you might recall of CRT TVs and 80s micros to
what a dedicated monochrome CRT would show, well, the dedicated CRT was much
better and sharper, particularly if your color display technology involved a
"composite" system like NTSC or PAL, where horizontal luminance (Y) bandwidth
was SEVERELY limited to "make room for" the color information (I/Q).

To get an idea of how much Composite video encoding degraded picture
information, take a look at modern videos of "RGB-modded" classic consoles
such as
[https://www.youtube.com/watch?v=kpdpAxzjmA8](https://www.youtube.com/watch?v=kpdpAxzjmA8)
\-- As far as I understand from the video explanation, both signals are video-
captured, so this is not a "CRT effect", it's a "composite video effect" that
makes the right-side image so smeared. There's also the palette difference,
but that's more a matter of preference.

~~~
SiempreViernes
What does the long decay times of forbidden transition lines have to do with
analogue circuits?

------
Vogtinator
There's a really interesting video about character generation on HP 264x
series terminals:
[https://www.youtube.com/watch?v=QikO0WOAGWI](https://www.youtube.com/watch?v=QikO0WOAGWI)

~~~
blattimwind
That's nothing! Tektronix did vector fonts in the 60s using analogue ROMs.

~~~
abainbridge
That's nothing, the Jaquet-Droz family were producing glyphs from mechanical
analogue storage in ~1770.
[https://www.youtube.com/watch?v=bY_wfKVjuJM](https://www.youtube.com/watch?v=bY_wfKVjuJM)

~~~
masswerk
Also, see the use of a metal plate as a binary storage device for fonts used
for the print on punch cards with the IBM key punches:

[https://www.masswerk.at/misc/card-punch-
typography/](https://www.masswerk.at/misc/card-punch-typography/)

------
Keyframe
Fantastic. My favourite terminal I worked on was the amber-colored vt320
hooked to a sun box and sometimes to an sgi. There was something special to
it, even 'back in the day'.

~~~
drudru11
Truth - the only problem with those old terminals was the keyboard. They
tended to not have the control key or ESC key (DEC terminals) in a nice spot.

------
edejong
Similar project is cool-retro-term [1] although I think the defaults are a
little over the top.

[1] [https://github.com/Swordfish90/cool-retro-
term](https://github.com/Swordfish90/cool-retro-term)

~~~
reaperducer
cool-retro-term is my go-to terminal program for quick projects that don't
need multiple panes.

It freaks out the IT guys and our workspace consultants, which is a bonus.

The only downside is that on macOS it crashes on quit. But since I'm quitting
it anyway, no harm done.

~~~
pushpop
Why would cool-retro-term “freak out” IT professionals any more than a typical
terminal emulator? Does “freak out” have some additional definition I’m
unaware of?

Personally I found cool-retro-term lacked support for a few ANSI escape
sequences I needed for tmux to work quite how I liked which prevented me using
it as my daily $TERM. I’m sure with a bit of effort I could have gotten it
working but it was an effort not work making when there’s literally dozens of
other ${TERM}s I could use and the only thing in favour of cool-retro-term is
novelty.

I do really like how cool-retro-term is an expansion of the acronym CRT.
Clever project naming.

~~~
reaperducer
_Why would cool-retro-term “freak out” IT professionals any more than a
typical terminal emulator?_

Because a typical terminal emulator doesn't make the brand new monitor they
just installed look like it's broken.

~~~
pushpop
Cool-retro-term doesn’t make a brand new monitor look like it’s broken. The
effect of CRT isn’t even remotely what an LCD looks like when it fails.

So I’m guessing when you say “IT professionals freak out” what you actually
mean is “idiot desktop support engineers who think anyone who uses the command
line are ‘l33t h4xx0rz’”.

In which case they’d have a hernia if they saw the kind of workspace a typical
non-poser runs.

~~~
reaperducer
_So I’m guessing when you say “IT professionals freak out” what you actually
mean is “idiot desktop support engineers who think anyone who uses the command
line are ‘l33t h4xx0rz’”._

You guessed wrong, since they're used to seeing me use iTerm all over my other
monitors.

------
int_19h
On an unrelated note, I wish somebody made a modern portable and low-power
hardware terminal. Something with eInk, or maybe even reflective LCD, like
those old "electronic organizers", but with a full-size screen. If it can do
serial and serial-over-USB, that can come in handy with headless boxes, RPi
etc.

~~~
reaperducer
Until that happens, Prompt for iOS by Panic Software out of Portland is very
useful. I've used it on my iPhone in emergencies for years, and recently put
it on an iPad and it really shines.

------
notevenodd
Is the HTML5 "workbench" VT100/220 emulation available to try? (Didn't see a
link to it)

------
burfog
DEC Terminal Modern, fitting the old character shapes but having smooth
outlines, is rather nice. It's almost like the new Chicago font, which Apple
remade as a vector font that would produce the original bitmaps if rendered at
the original size.

I'd like to see that for the "fixed" font used as the xterm default. I got
addicted to this font, but pixels are getting smaller and my eyes are getting
worse.

------
jhallenworld
We need the VT52 experience: relay clicks as you type.

~~~
ch_123
Some of IBM's mainframe terminals used a solenoid which would hit the side of
the keyboard's case to indicate that a key-press was successfuly registered.
This was in addition to the well documented clicking noise of IBM's keyboard
switches.

~~~
dfox
IIRC original 3270 keyboard had solenoid that physically prevented user from
pressing any key when the terminal was busy and would not be able to register
the key press.

~~~
ch_123
The solenoid on the one which I have (a 3278 keyboard) is separate to the
keys. It is true that the solenoid will not operate when the terminal is
unable to accept any key press, but it does not impede the operation of the
keys themselves.

To the best of my knowledge, the only IBM keyboards that could flat out
prevent the keys from being pressed were ones based on the Selectric
typewriter mechanism, such as the 2741

~~~
kps
In order to prevent two keys being active simultaneously, the Selectric had a
linear track full of steel balls running from side to side, with just enough
free space to allow a metal tab from a single key to enter. So locking the
keyboard was just a matter of having a solenoid occupy the free space.

------
geuszb
Excellent research. I wonder who the artist is who drew the typeface and
whether they realized at the time that it would have such significance that
somebody would still be studying their work so many decades later

------
reaperducer
It's interesting that DEC did horizontal pixel stretching because individual
dots would be too precise to be seen because of phosphor latency.

The Commodore 64 had a similar problem with single-pixel latency, which is why
the vertical portions of its character ROM are all two pixels wide. Otherwise,
the character would be too blurry to be read comfortably on televisions of the
era.

I used to love making my own C-64 fonts pixel by pixel and comparing how they
looked on a Panasonic portable TV versus my Commodore CM-141 monitor.

------
cat199
this is great!

I'm a regular user of the glasstty font + the 'tritty'[1] utility which
emulates serial line I/O to create the 'true unix terminal' experience.

Looking forward to the next post!

ps: improved smeary-220 font would be great :b

.. [1]
[https://github.com/sjmulder/trickle](https://github.com/sjmulder/trickle)

~~~
dfox
I'm not sure that all the smearing and blur is historically accurate for
vt220. I still have Wyse WY-150 (IIRC) on my desk and while it has somewhat
poor contrast (which seems to be mainly caused by worn out contrast pot, I
gotta fix that someday), it has exceptionally crisp display. I remember the
same "crispness" feeling from various amber phosphor MDA monitors.

~~~
cat199
good point - I actually do have a 320 and the topics discussed in the article
seem to jive with my experience with it..

but yes, it is very crisp - i think the point of the 'fuzzing' details
discussed here is that they actually help the overall clarity (e.g. a
'dithering' sort of effect)

------
ChickeNES
I need to find/buy an eeprom and programmer for my VT102, the character ROMs
are failing and the text is totally garbled

------
bepvte
This is great! Id love if this expertise was added to the cool-retro-term
project.

