Building a Tetris Clone in X86 Assembly, Pt. Ⅰ: Hello, World | Hacker News Reader

Building a Tetris Clone in X86 Assembly, Pt. Ⅰ: Hello, World

cmcenroe.me

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Tetris seems to be one of those games that people love to size-optimise in Asm; here's a few in the <512b category:

http://www.pouet.net/prod.php?which=33942

http://www.pouet.net/prod.php?which=6951

There was a competition too, based on a standard appearance and behaviour, and the winner is 363 bytes:

https://files.scene.org/view/mags/hugi/compos/hc22fin.zip

Vaguely related; chess game in 487 bytes:

https://news.ycombinator.com/item?id=8954630

It's not 100% related but I had great fun building a very minimal Tetris clone in 6502 assembly, for the C=64, a couple of years ago (the code is "kinda" commented):

https://github.com/cjauvin/tetris-464

Is anybody able to get the repo running? 'make qemu' simply shows a blank screen and exits. But the repo seems much farther along than the blog post.

The build defaults to debug, so `make qemu` also starts QEMU waiting for a debugger to attach. `make qemu BUILD=release` won't.

Thanks!

there's no comment section there so i'd figure i'd ask here: what is that font that it outputs? is that part of BIOS or something? or part of boot loader or PXE server?

i assumed asm was the lowest level, is there some builtin font by default that can't be changed or something?

I haven't read through the tutorial, but I would assume that the programmer does not specify the fonts being used, but rather outputs bytes to stdout. It's the terminal emulator that's running the program that is responsible for displaying those bytes, so that's where things like font would be set.

It is indeed the default BIOS font. You usually get it when switching to a TTY on Linux, as well.

But of course nowadays most distributions use KMS and put the consoles in a graphics mode on which the virtual console is emulated.

The default video bios mode is used as-is here, https://en.wikipedia.org/wiki/Video_BIOS

There is no terminal emulator here. This hello world text is written directly to video memory -- and yes, there is a character rom, so placing a string of words in memory OR'd with bits set for video attributes (the #defines there) make it color.

Furthermore, see an example of setting the mode explicitly from PC-DOS: https://github.com/johannesl/EditANSi/blob/master/ea.asm#L23 and http://fleder44.net/312/notes/18Graphics/index.html