5 ms·

CGA in 1024 colors – a new mode (2015)

125 points by tomduncalf 3y ago

theandrewbailey 3y ago
(2015)
- dang 3y ago
  Added. Thanks!
tecleandor 3y ago
This is about the "8088 MPH" demo for an original IBM PC ( previously in 2015: https://news.ycombinator.com/item?id=9338944 https://news.ycombinator.com/item?id=9338944 ) Then "succeeded" by "Area 5150" past year: https://news.ycombinator.com/item?id=32394195 https://news.ycombinator.com/item?id=32394195
- layer8 3y ago
  It seems that a decent 8088/CGA version of Second Reality should be in the cards.
  - mikejarema 3y ago
    Hopefully! But until then we do have the C64 version to enjoy: https://www.pouet.net/prod.php?which=1216 https://www.pouet.net/prod.php?which=1216
    - porbelm 3y ago
      I think that Smash Designs' Second Reality has the most amazingly programmed SID music out there, I'd love to see a write-up of how that was made.
keithnoizu 3y ago
and I felt like a rebel just using vga x mode.
- 1letterunixname 3y ago
  Square pixel 360×240 was sane, but 360×480 always felt dirty. IIRC, Mode X video mode set routines boiled down to an exhaustive table of VGA register control values. (See SDL or older FreeBSD for examples.) Then, the fun was pixel addressing, bitblting, and page flipping.
  - p1mrx 3y ago
    > Square pixel 360×240 Did you mean 320×240?
    - Dwedit 3y ago
      360x240 and 360x480 are both real modes. But it was 320x240 that had the square pixels.
    - 1letterunixname 3y ago
      Yes, Google. ;@P Thanks. 360x270 wouldn't be possible with VGA. 4:3 pixel aspect ratios of mode X-like VGA modes 256×256: 1.0 (Stretched) 320×200: 1.6 (Mode 13h - slightly squished) 320×224: 1.428.. (Imperceptibly squished) 320×240: 1.333.. (Square) 320×350: 0.914.. (Stretched) 320×400: 0.8 (Stretched) 320×480: 0.666.. (Extremely stretched) 360×200: 1.8 (Very squished) 360×240: 1.5 (Imperceptibly squished except when drawing circles) (360×270 is impossible) 360×350: 1.029.. (Slightly stretched) 360×400: 0.9 (Stretched) 360×480: 0.75 (Extremely stretched) 400×300: 1.333.. (Square)
- marmakoide 3y ago
  I felt like an unknown genius using 256x256 unchained VGA : marginally faster sprites ! Sprite clipping using a 4 pixels out of screen border !
dang 3y ago
Related: CGA in 1024 Colors – A New Mode: The Illustrated Guide (2015) - https://news.ycombinator.com/item?id=21992870 https://news.ycombinator.com/item?id=21992870 - Jan 2020 (69 comments) CGA in 1024 Colors – A New Mode: The Illustrated Guide - https://news.ycombinator.com/item?id=9386505 https://news.ycombinator.com/item?id=9386505 - April 2015 (11 comments)
hyperman1 3y ago
Look at the referenced IBM docs: They included the actual schematics of the adapters. I don't know if they are 100% complete, but even so, that level of technical detail is almost unimaginable now. (I hope the link works, otherwise, see e.g. page 19=28). https://archive.org/details/bitsavers_ibmpccardsptionsandAdaptersVolume2Apr84_25079400/page/n27/mode/2up?view=theater https://archive.org/details/bitsavers_ibmpccardsptionsandAda...
- dekhn 3y ago
  that seems pretty typical for a datasheet?
  - userbinator 3y ago
    Try getting that level of documentation for a modern or even just slightly older (as in a decade ago) GPU.
  - hyperman1 3y ago
    The fact that the public could get these at all. I have another one of these with the BIOS source code. I don't think e.g. HP would publish a schematic or BIOS source for one of their laptops today(I'd love it if you prove me wrong, of course) . Otoh, I have an old 1960's tube radio, and the full circuit is attached to the backplate, in the expectation that you might want to replace a resistor some day.
    - actionfromafar 3y ago
      I was gonna say, "or tube", but then again, I think the tubes were standard models so you'd just bring your tubes in to the department store, test them in the tube tester⁰ and get your replacement. 0: http://oldradios.50webs.com/precision/ http://oldradios.50webs.com/precision/
    - dekhn 3y ago
      BIOS is still a shitshow; an ex-coworker of mine has been working on open bios for several decades now https://www.usenix.org/conference/als-2000/linux-bios https://www.usenix.org/conference/als-2000/linux-bios
esafak 3y ago
https://en.wikipedia.org/wiki/List_of_16-bit_computer_color_palettes https://en.wikipedia.org/wiki/List_of_16-bit_computer_color_...
deleted 3y ago
[deleted]
thanatos519 3y ago
I made a Mandelbrot renderer for something like this 30 years ago. Never realized it would look so good if I plugged it in my TV.

125 points by tomduncalf 3y ago

theandrewbailey 3y ago

(2015)

dang 3y ago
Added. Thanks!

tecleandor 3y ago

This is about the "8088 MPH" demo for an original IBM PC ( previously in 2015: https://news.ycombinator.com/item?id=9338944 https://news.ycombinator.com/item?id=9338944 ) Then "succeeded" by "Area 5150" past year: https://news.ycombinator.com/item?id=32394195 https://news.ycombinator.com/item?id=32394195

layer8 3y ago
It seems that a decent 8088/CGA version of Second Reality should be in the cards.
- mikejarema 3y ago
  Hopefully! But until then we do have the C64 version to enjoy: https://www.pouet.net/prod.php?which=1216 https://www.pouet.net/prod.php?which=1216
  - porbelm 3y ago
    I think that Smash Designs' Second Reality has the most amazingly programmed SID music out there, I'd love to see a write-up of how that was made.

keithnoizu 3y ago

and I felt like a rebel just using vga x mode.

1letterunixname 3y ago
Square pixel 360×240 was sane, but 360×480 always felt dirty. IIRC, Mode X video mode set routines boiled down to an exhaustive table of VGA register control values. (See SDL or older FreeBSD for examples.) Then, the fun was pixel addressing, bitblting, and page flipping.
- p1mrx 3y ago
  > Square pixel 360×240 Did you mean 320×240?
  - Dwedit 3y ago
    360x240 and 360x480 are both real modes. But it was 320x240 that had the square pixels.
  - 1letterunixname 3y ago
    Yes, Google. ;@P Thanks. 360x270 wouldn't be possible with VGA. 4:3 pixel aspect ratios of mode X-like VGA modes 256×256: 1.0 (Stretched) 320×200: 1.6 (Mode 13h - slightly squished) 320×224: 1.428.. (Imperceptibly squished) 320×240: 1.333.. (Square) 320×350: 0.914.. (Stretched) 320×400: 0.8 (Stretched) 320×480: 0.666.. (Extremely stretched) 360×200: 1.8 (Very squished) 360×240: 1.5 (Imperceptibly squished except when drawing circles) (360×270 is impossible) 360×350: 1.029.. (Slightly stretched) 360×400: 0.9 (Stretched) 360×480: 0.75 (Extremely stretched) 400×300: 1.333.. (Square)
marmakoide 3y ago
I felt like an unknown genius using 256x256 unchained VGA : marginally faster sprites ! Sprite clipping using a 4 pixels out of screen border !

dang 3y ago

Related: CGA in 1024 Colors – A New Mode: The Illustrated Guide (2015) - https://news.ycombinator.com/item?id=21992870 https://news.ycombinator.com/item?id=21992870 - Jan 2020 (69 comments) CGA in 1024 Colors – A New Mode: The Illustrated Guide - https://news.ycombinator.com/item?id=9386505 https://news.ycombinator.com/item?id=9386505 - April 2015 (11 comments)

hyperman1 3y ago

Look at the referenced IBM docs: They included the actual schematics of the adapters. I don't know if they are 100% complete, but even so, that level of technical detail is almost unimaginable now. (I hope the link works, otherwise, see e.g. page 19=28). https://archive.org/details/bitsavers_ibmpccardsptionsandAdaptersVolume2Apr84_25079400/page/n27/mode/2up?view=theater https://archive.org/details/bitsavers_ibmpccardsptionsandAda...

dekhn 3y ago
that seems pretty typical for a datasheet?
- userbinator 3y ago
  Try getting that level of documentation for a modern or even just slightly older (as in a decade ago) GPU.
- hyperman1 3y ago
  The fact that the public could get these at all. I have another one of these with the BIOS source code. I don't think e.g. HP would publish a schematic or BIOS source for one of their laptops today(I'd love it if you prove me wrong, of course) . Otoh, I have an old 1960's tube radio, and the full circuit is attached to the backplate, in the expectation that you might want to replace a resistor some day.
  - actionfromafar 3y ago
    I was gonna say, "or tube", but then again, I think the tubes were standard models so you'd just bring your tubes in to the department store, test them in the tube tester⁰ and get your replacement. 0: http://oldradios.50webs.com/precision/ http://oldradios.50webs.com/precision/
  - dekhn 3y ago
    BIOS is still a shitshow; an ex-coworker of mine has been working on open bios for several decades now https://www.usenix.org/conference/als-2000/linux-bios https://www.usenix.org/conference/als-2000/linux-bios

esafak 3y ago

https://en.wikipedia.org/wiki/List_of_16-bit_computer_color_palettes https://en.wikipedia.org/wiki/List_of_16-bit_computer_color_...

deleted 3y ago

[deleted]

thanatos519 3y ago

I made a Mandelbrot renderer for something like this 30 years ago. Never realized it would look so good if I plugged it in my TV.