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  • ms-dos text mode tricks

    From hollowone@21:2/150 to All on Fri Dec 29 14:10:22 2023
    can somebody point me to some good tutorials how to play some visual tricks in MS-DOS terminal via coding?

    I saw examples of smooth fade in and fade out. also some non-standard palette in MS DOS text modes. I was wondering how those were done.

    any experience from those ancient times?

    -h1

    ... Xerox Alto was the thing. Anything after we use is just a mere copy.

    --- Mystic BBS v1.12 A48 (Linux/64)
    * Origin: 2o fOr beeRS bbS>>20ForBeers.com:1337 (21:2/150)
  • From NuSkooler@21:1/121 to hollowone on Fri Dec 29 19:37:53 2023

    On Friday, December 29th hollowone said...
    can somebody point me to some good tutorials how to play some visual tricks in MS-DOS terminal via coding?

    Look to the docs on DOS ANSI.SYS. You have basic color/movement/etc. functionality.


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  • From hollowone@21:2/150 to NuSkooler on Sat Dec 30 01:10:20 2023
    Look to the docs on DOS ANSI.SYS. You have basic color/movement/etc. functionality.

    I know ANSI.SYS, it is covering ANSI escape codes. I don't need that. I have my own printf alike function that parses ANSI escape codes within my app if I need ansi art and this way ANSI.SYS is just obsolete for this task.

    What I'm looking for is more VGA orientated than DOS thing.
    I believe some VGA ports need to be hacked to achieve something like:
    1) I print text, normal black bg color, lgray fg color
    2) then without changing the colors or anything with the text layout I just see it smoothly fading into black.

    This is more demoscene trick than BBS thing. That's why ANSI.SYS brings no help, just memory burden.

    I saw it in many demo productions while loading back in the 90s and I think there was some tech reference available back then, I just can't find it now.

    -h1

    ... Xerox Alto was the thing. Anything after we use is just a mere copy.

    --- Mystic BBS v1.12 A48 (Linux/64)
    * Origin: 2o fOr beeRS bbS>>20ForBeers.com:1337 (21:2/150)
  • From Aurelius@21:1/175 to hollowone on Sat Dec 30 04:07:23 2023
    Re: RE: ms-dos text mode tricks
    By: NuSkooler to hollowone on Fri Dec 29 2023 19:37:53

    A lot of weird tricks were done by directly accessing the BIOS directly, or the VGA card's registers. It's how this virus from the early 90's called BIGJOKE did some neat visual tricks. I actually decompiled it with Ghidra to see what it was doing.
    Aurelius
    --- SBBSecho 3.14-Linux
    * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (21:1/175)
  • From hollowone@21:2/150 to hollowone on Sat Dec 30 01:38:05 2023
    What I'm looking for is more VGA orientated than DOS thing.
    I believe some VGA ports need to be hacked to achieve something like:
    1) I print text, normal black bg color, lgray fg color
    2) then without changing the colors or anything with the text layout I just see it smoothly fading into black.

    And I just found a working example with source code: https://hornet.org/code/library/rvga01.zip

    If you're curious what I meant in above requirements, visually proven, download the zip, and launch t_exp-03.exe that shows the effect very well.

    -h1

    ... Xerox Alto was the thing. Anything after we use is just a mere copy.

    --- Mystic BBS v1.12 A48 (Linux/64)
    * Origin: 2o fOr beeRS bbS>>20ForBeers.com:1337 (21:2/150)
  • From hollowone@21:2/150 to Aurelius on Sat Dec 30 10:13:18 2023
    A lot of weird tricks were done by directly accessing the BIOS directly, or the VGA card's registers.

    Yep, that's how I did it. The effect I wanted to achieve was actually quite easy. I just did not know that indexed palette can be also modified in text modes. Funny discovery as I can provide completely different 16 foreground, 8 bg colors than standard palette.

    Which again is totally not usable in the BBS world, but interesting concept to experiment in just plain text mode MS-DOS demo.

    -h1

    ... Xerox Alto was the thing. Anything after we use is just a mere copy.

    --- Mystic BBS v1.12 A48 (Linux/64)
    * Origin: 2o fOr beeRS bbS>>20ForBeers.com:1337 (21:2/150)
  • From paulie420@21:2/150 to hollowone on Sat Dec 30 18:27:07 2023
    And I just found a working example with source code: https://hornet.org/code/library/rvga01.zip

    Thats pretty fun - I don't have a bunch IN MIND, but know theres many different things like this that show basic demoscene DOS code... remember the intro makers from back in the day.



    |07p|15AULIE|1142|07o
    |08.........

    --- Mystic BBS v1.12 A48 (Linux/64)
    * Origin: 2o fOr beeRS bbS>>20ForBeers.com:1337 (21:2/150)