Back in the '80s we used to materially improve our daily work experience by replacing the 2708 1Kx8 EPROM screen font map chip in our Z19 terminals with our own that specified wider verticals, after the manner of the VT100's pixel stretching. Otherwise horizontals would be substantially brighter than verticals, which looked awful.
We never knew why the VT100 looked better than other terminals; this is the first I have heard of the pixel stretching. Elegant design, for its day.
A more common trick was to have a 9-dot character cell with an 8-bit font ROM, and double the rightmost bit of each cell, mainly so that underscores would connect. Thus, most characters occupied 7 pixels, with 2 blank pixels between.
The latter trick is also present in the VT100: in 80 cols mode the font matrix is stretched from 9×10 to 10×10 by replicating the rightmost pixel, which is only set in horizontals of line-drawing characters (with dot-streching closing any remaining gaps).
It should be possible to programmatically modify fonts to add CRT-ness to them.
Another interesting CRT feature happens on the CDC 6x00 consoles. They use vector fonts and often show relatively large amounts of text. The geometry of the screen font ends up being deformed by the response of the analog components of the xy beam positioning, giving it a slightly odd (for something that was, at the time, the fastest computer ever built) comic book character.
I submitted as 'DEC' but unfortunately there's some automangling on headlines - presumably to avoid shrieking all-caps ones. @dang might be able to rectify it...?
Anyway, thanks for the article - it was an interesting read that I stumbled upon while wondering-via-google what fonts the DEC manuals were printed with.
Thanks for liking it. Admittedly, at first, I didn't know, if this would make a story at all, but decided to do the writeup anyway. So everyone enjoying it is decidedly a win.
It's the kind of thing I'd love to see more of here. Err more on the side of submitting maybe?
I am a little bit nostalgic about DEC stuff from college years working on projects in rooms full of VT220s connected to a small cluster. There's an advert on the local (Stockholm, Sweden) listings currently for a VaxStation and it's oh so tempting to pick it up and have a play with VMS again!
BTW, regarding the font used in DEC manual, I've been looking for this as well, to not much avail. I think, the print on the control panels of the early machines is Neuzeit S, if this is of any help.
This was absolutely awesome! Seeing how you took the font from the first ROM images to something that is reasonably close to the original display is pretty cool!
https://github.com/Swordfish90/cool-retro-term is pretty good at emulating the old terminals, from memory the DOS stuff is pretty close to what the old CGA's mono monitors looked like.
Fantastic work - nearly perfect, as far as I can tell. Really brings me back to college days in the late 80s doing programming assignments on the computer lab VAX terminals. Maybe you can do the DECwriter font next :-)
We never knew why the VT100 looked better than other terminals; this is the first I have heard of the pixel stretching. Elegant design, for its day.
A more common trick was to have a 9-dot character cell with an 8-bit font ROM, and double the rightmost bit of each cell, mainly so that underscores would connect. Thus, most characters occupied 7 pixels, with 2 blank pixels between.