7 ms·

VGA ROM Fonts (2020)

88 points by Lammy 6y ago

h2odragon 6y ago
Font loader TSRs... Blast from the past there. You don't have to have the font table resident in the "resident" kernel of the TSR, hook timer and 21h and use the timer to check if the VGA font table has been changed; when it has, raise a flag and next 21h hook can safely re-read that data from a file and cram it into video ram again.
- SavantIdiot 6y ago
  Do you recall "DOSBLOOD.EXE", a font loader TSR that made the letters look like they were dripping?
  - gfaure 6y ago
    This sounds fascinating, although "DOSBLOOD.EXE" only returns one Google result, being this comment. I assume it would work by constantly modifying the bitmap font?
    - h2odragon 6y ago
      iirc thats what it did, cycled through a "palette" of bitmap fonts, but i dont recall if it did the whole block or individual characters...
    - SavantIdiot 6y ago
      lol. that's funny. no it wasn't animated, just drippy letters. and it was 1995 so i might have misspelled it, memory and all.
caf 6y ago
We used to erase those eproms with sunlight. Took a lot longer, but seems a lot safer than that rig!
- pestatije 6y ago
  Yes, that rig looks too close to a Darwin award.
- VLM 6y ago
  The irony is real erasers, sometimes even UL and OSHA approved, have cost less than ten eprom chips since the 80s, and have always cost a quarter to a tenth what an eprom programmer costs, so all the effort and danger is not saving very much. Ten eproms seems like a lot to people born after the eprom era, but when every build and test cycle requires at least one (or maybe 2 for a 16 bit system, etc) then you can see why people tended to accumulate a hoard of eproms so they'd always have clean erased ready to use ones while actively programming, and erase was done in bulk either because the eraser held 16 chips at once or the erase process could be done in parallel with downtime (while watching TV or something). Also in some cases during the transition era of UV to EEPROM hardware I remember some EEPROMs were pin for pin compatible with some EPROMs and nobody likes waiting for UV, EEPROMs are simply faster. Obviously not all EPROMs have an identical or faster EEPROM twin, but "many" do.
- swineyy 6y ago
  The UVC lamp setup seems dangerous as fuck - exposed live AC voltage AND mercury??? If you're in need of erasing EEPROMs, just do yourself a favor and buy 10mW UVC 265nm LED. A single LED should suffice to erase a single EEPROM chip within 10-15 minutes.
  - tyingq 6y ago
    Most popular UV EPROMS have an electrically eraseable EEPROM equivalent, so you can usually avoid it altogether. In the case of the 27C256 in the article, a 29C256 would be a pin compatible drop-in.
  - progman32 6y ago
    Psh, I've used a TIG welder's arc as an impromptu EPROM eraser. Worked great. It's on video somewhere but I'm not posting it here :) But yeah, LED is the way to go. Normal "black light" LEDs won't work, I tried. Do as parent says.
SavantIdiot 6y ago
After 30+ years of XGA and higher I've forgotten what coding on an 80x25 terminal felt like. Cramped. The answer is "cramped".
- rbanffy 6y ago
  It depends on the language. Modern languages feel like that because they evolved on high resolution workstation screens with GUIs that could use smaller fonts. You can do 132x50 on most SVGA cards, but you’ll want a bigger screen for that (and the fonts will be ugly 8x8 or 6x8 ones). Writing BASIC on 80x25 feels constrained, but 80x35 is much better. Java would be a lot more concise if it was designed with VT-100s in mind.
  - swiley 6y ago
    C# feels cramped unless you have huge desktop monitors.
    - sedatk 6y ago
      Luckily, that’s changing. C# 10 is converting namespace blocks into directives like Java. That means one fewer indent.
      - zorked 6y ago
        Do people indent namespaces in C#? In C++ it's common practice to not indent.
        sedatk 6y ago
        Yes, it's traditional with C# to indent every multi-line block. There are teams and individuals who opt for some exceptions (like switch/case), but none of them are universally adopted. I haven't seen a single example over the last two decades where namespaces aren't indented. The defaults go a long way.
  - kjs3 6y ago
afturkrull 6y ago
On that website, why don't the text word wrap when I zoom in?
- tyingq 6y ago
  Because the css is forcing display:table, display:table row, and display:table cell on some divs and a fixed 1024px width. Remove all that and it zooms in/out fine. No idea why it's styled that way.
pdenton 6y ago
For actual fonts you can use in your terminal emulators and whatnot, visit https://int10h.org/oldschool-pc-fonts/download/ https://int10h.org/oldschool-pc-fonts/download/
- khm 6y ago
  Those are missing tons of Unicode glyphs, for obvious reasons. Dmitry Bolkhovityanov maintains an expanded-coverage font[1] which has been converted to many useful formats[2]. 1 - https://www.inp.nsk.su/~bolkhov/files/fonts/univga/ https://www.inp.nsk.su/~bolkhov/files/fonts/univga/ 2 - http://sciops.net/downloads/vga/ http://sciops.net/downloads/vga/ (my site)
  - Lammy 6y ago
    Thanks for this. I've been using Zeh Fernando's "Perfect DOS VGA 473" (and derivatives like http://laemeur.sdf.org/fonts/ http://laemeur.sdf.org/fonts/) for ages but have been looking for a replacement since those only cover CP473/Windows-1252. Also very happy to see an outline version on your site since BDF fonts aren't very usable after Pango 1.44 broke support for them: https://gitlab.gnome.org/GNOME/pango/-/issues/386 https://gitlab.gnome.org/GNOME/pango/-/issues/386
bogomipz 6y ago
Can anyone say what the characters in rows B, C and D in their character map here would be used for? http://www.alexandrugroza.ro/microelectronics/essays-research/vga-rom-fonts/_pict/vga-rom-fonts-fontraption3.jpg http://www.alexandrugroza.ro/microelectronics/essays-researc...
- EvanAnderson 6y ago
  Those are line-drawing and shading characters. They were used all the time in MS-DOS programs (to great good, in my opinion) for textual "windowing" UIs (a "TUI"). A good example is Turbo Vision: https://en.wikipedia.org/wiki/Turbo_Vision https://en.wikipedia.org/wiki/Turbo_Vision
  - bogomipz 6y ago
    Ah yes, interesting. I guess seeing them sort of "out of context" stumped me. Cheers.
- a_e_k 6y ago
  https://en.wikipedia.org/wiki/Code_page_437 https://en.wikipedia.org/wiki/Code_page_437
EvanAnderson 6y ago
This is as good of a place as any to ask this: Years ago when I envied demoscene programmers I tried to do animation by way of the redefining VGA font table quickly. I never succeeded in getting that to work for any reasonable frame-rate. Is anybody aware of examples of software that did that and were able to achieve a reasonable frame-rate? I'd love to look at the code, even >25 years later, just for fun.
- trollbridge 6y ago
  I can’t think of any, but it would be trivial to do, just update bitplane 2. On some cards you need to update it during vsync.
mrlonglong 6y ago
My terminal shell is still 132x43 despite not having used a real VT220 for decades. I have an Amstrad pc1512 emulator that I use for fun sometimes, that one has a really nice font that I loved.
peter_d_sherman 6y ago
>"Thus I began designing the font of my dreams. Some might find it beautiful, some might find it ugly. But I love it. It is the first iteration of the font and I'm happy with it. I did a lot of work on these fonts and I find then usable for now. The base font for my design was the original one that I recovered from the ET4000/W32i ROM. Then I tried hard to remember what the old fonts looked like. I also drew inspiration from the ATI VGA Wonder 16 ROM font." PDS: I think they're awesome! >"This is my Micro-Labs Tseng Labs ET4000/W32i ISA card. I find it very beautifully laid out.' [...] "The card clocks are built around the CHRONTEL CH9294 dual PLL graphics clock generator integrated circuit. These are still available on various sites. The RAMDAC is an AT&T ATT20C490-80 part. These are also available on-line. The ET4000/W32i chip is also available on-line. Which makes me think: what if I'd build my own VGA card? I still have the Tseng Labs datasheets catalog and this VGA controller along with a sample schematic is described in depth. I could improve that design by using modern memories which would be cheaper and easier to source. But this is another topic. For the moment it is only food for thought." PDS: I think it's a great idea! Excellent article, all in all! Well worth re-reading in the future!

88 points by Lammy 6y ago

Font loader TSRs... Blast from the past there. You don't have to have the font table resident in the "resident" kernel of the TSR, hook timer and 21h and use the timer to check if the VGA font table has been changed; when it has, raise a flag and next 21h hook can safely re-read that data from a file and cram it into video ram again.

SavantIdiot 6y ago
Do you recall "DOSBLOOD.EXE", a font loader TSR that made the letters look like they were dripping?
- gfaure 6y ago
  This sounds fascinating, although "DOSBLOOD.EXE" only returns one Google result, being this comment. I assume it would work by constantly modifying the bitmap font?
  - h2odragon 6y ago
    iirc thats what it did, cycled through a "palette" of bitmap fonts, but i dont recall if it did the whole block or individual characters...
  - SavantIdiot 6y ago
    lol. that's funny. no it wasn't animated, just drippy letters. and it was 1995 so i might have misspelled it, memory and all.

caf 6y ago

We used to erase those eproms with sunlight. Took a lot longer, but seems a lot safer than that rig!

pestatije 6y ago
Yes, that rig looks too close to a Darwin award.
VLM 6y ago
The irony is real erasers, sometimes even UL and OSHA approved, have cost less than ten eprom chips since the 80s, and have always cost a quarter to a tenth what an eprom programmer costs, so all the effort and danger is not saving very much. Ten eproms seems like a lot to people born after the eprom era, but when every build and test cycle requires at least one (or maybe 2 for a 16 bit system, etc) then you can see why people tended to accumulate a hoard of eproms so they'd always have clean erased ready to use ones while actively programming, and erase was done in bulk either because the eraser held 16 chips at once or the erase process could be done in parallel with downtime (while watching TV or something). Also in some cases during the transition era of UV to EEPROM hardware I remember some EEPROMs were pin for pin compatible with some EPROMs and nobody likes waiting for UV, EEPROMs are simply faster. Obviously not all EPROMs have an identical or faster EEPROM twin, but "many" do.
swineyy 6y ago
The UVC lamp setup seems dangerous as fuck - exposed live AC voltage AND mercury??? If you're in need of erasing EEPROMs, just do yourself a favor and buy 10mW UVC 265nm LED. A single LED should suffice to erase a single EEPROM chip within 10-15 minutes.
- tyingq 6y ago
  Most popular UV EPROMS have an electrically eraseable EEPROM equivalent, so you can usually avoid it altogether. In the case of the 27C256 in the article, a 29C256 would be a pin compatible drop-in.
- progman32 6y ago
  Psh, I've used a TIG welder's arc as an impromptu EPROM eraser. Worked great. It's on video somewhere but I'm not posting it here :) But yeah, LED is the way to go. Normal "black light" LEDs won't work, I tried. Do as parent says.

SavantIdiot 6y ago

After 30+ years of XGA and higher I've forgotten what coding on an 80x25 terminal felt like. Cramped. The answer is "cramped".

rbanffy 6y ago
It depends on the language. Modern languages feel like that because they evolved on high resolution workstation screens with GUIs that could use smaller fonts. You can do 132x50 on most SVGA cards, but you’ll want a bigger screen for that (and the fonts will be ugly 8x8 or 6x8 ones). Writing BASIC on 80x25 feels constrained, but 80x35 is much better. Java would be a lot more concise if it was designed with VT-100s in mind.
- swiley 6y ago
  C# feels cramped unless you have huge desktop monitors.
  - sedatk 6y ago
    Luckily, that’s changing. C# 10 is converting namespace blocks into directives like Java. That means one fewer indent.
    - zorked 6y ago
      Do people indent namespaces in C#? In C++ it's common practice to not indent.
      - sedatk 6y ago
        Yes, it's traditional with C# to indent every multi-line block. There are teams and individuals who opt for some exceptions (like switch/case), but none of them are universally adopted. I haven't seen a single example over the last two decades where namespaces aren't indented. The defaults go a long way.
- kjs3 6y ago

afturkrull 6y ago

On that website, why don't the text word wrap when I zoom in?

tyingq 6y ago
Because the css is forcing display:table, display:table row, and display:table cell on some divs and a fixed 1024px width. Remove all that and it zooms in/out fine. No idea why it's styled that way.

pdenton 6y ago

For actual fonts you can use in your terminal emulators and whatnot, visit https://int10h.org/oldschool-pc-fonts/download/ https://int10h.org/oldschool-pc-fonts/download/

khm 6y ago
Those are missing tons of Unicode glyphs, for obvious reasons. Dmitry Bolkhovityanov maintains an expanded-coverage font[1] which has been converted to many useful formats[2]. 1 - https://www.inp.nsk.su/~bolkhov/files/fonts/univga/ https://www.inp.nsk.su/~bolkhov/files/fonts/univga/ 2 - http://sciops.net/downloads/vga/ http://sciops.net/downloads/vga/ (my site)
- Lammy 6y ago
  Thanks for this. I've been using Zeh Fernando's "Perfect DOS VGA 473" (and derivatives like http://laemeur.sdf.org/fonts/ http://laemeur.sdf.org/fonts/) for ages but have been looking for a replacement since those only cover CP473/Windows-1252. Also very happy to see an outline version on your site since BDF fonts aren't very usable after Pango 1.44 broke support for them: https://gitlab.gnome.org/GNOME/pango/-/issues/386 https://gitlab.gnome.org/GNOME/pango/-/issues/386

bogomipz 6y ago

Can anyone say what the characters in rows B, C and D in their character map here would be used for? http://www.alexandrugroza.ro/microelectronics/essays-research/vga-rom-fonts/_pict/vga-rom-fonts-fontraption3.jpg http://www.alexandrugroza.ro/microelectronics/essays-researc...

EvanAnderson 6y ago
Those are line-drawing and shading characters. They were used all the time in MS-DOS programs (to great good, in my opinion) for textual "windowing" UIs (a "TUI"). A good example is Turbo Vision: https://en.wikipedia.org/wiki/Turbo_Vision https://en.wikipedia.org/wiki/Turbo_Vision
- bogomipz 6y ago
  Ah yes, interesting. I guess seeing them sort of "out of context" stumped me. Cheers.
a_e_k 6y ago
https://en.wikipedia.org/wiki/Code_page_437 https://en.wikipedia.org/wiki/Code_page_437

EvanAnderson 6y ago

This is as good of a place as any to ask this: Years ago when I envied demoscene programmers I tried to do animation by way of the redefining VGA font table quickly. I never succeeded in getting that to work for any reasonable frame-rate. Is anybody aware of examples of software that did that and were able to achieve a reasonable frame-rate? I'd love to look at the code, even >25 years later, just for fun.

trollbridge 6y ago
I can’t think of any, but it would be trivial to do, just update bitplane 2. On some cards you need to update it during vsync.

mrlonglong 6y ago

My terminal shell is still 132x43 despite not having used a real VT220 for decades. I have an Amstrad pc1512 emulator that I use for fun sometimes, that one has a really nice font that I loved.

peter_d_sherman 6y ago

>"Thus I began designing the font of my dreams. Some might find it beautiful, some might find it ugly. But I love it. It is the first iteration of the font and I'm happy with it. I did a lot of work on these fonts and I find then usable for now. The base font for my design was the original one that I recovered from the ET4000/W32i ROM. Then I tried hard to remember what the old fonts looked like. I also drew inspiration from the ATI VGA Wonder 16 ROM font." PDS: I think they're awesome! >"This is my Micro-Labs Tseng Labs ET4000/W32i ISA card. I find it very beautifully laid out.' [...] "The card clocks are built around the CHRONTEL CH9294 dual PLL graphics clock generator integrated circuit. These are still available on various sites. The RAMDAC is an AT&T ATT20C490-80 part. These are also available on-line. The ET4000/W32i chip is also available on-line. Which makes me think: what if I'd build my own VGA card? I still have the Tseng Labs datasheets catalog and this VGA controller along with a sample schematic is described in depth. I could improve that design by using modern memories which would be cheaper and easier to source. But this is another topic. For the moment it is only food for thought." PDS: I think it's a great idea! Excellent article, all in all! Well worth re-reading in the future!