Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

https://github.com/svendahlstrand/10-print-game-boy

🖨 Port of a famous C64 BASIC one-liner to the Game Boy.
https://github.com/svendahlstrand/10-print-game-boy

10-print 10print assembly game-boy gameboy rgbds

Last synced: 2 months ago
JSON representation

🖨 Port of a famous C64 BASIC one-liner to the Game Boy.

Lists

README 

        
`10 PRINT` Game Boy

===================



`10 PRINT CHR$(205.5+RND(1)); : GOTO 10` is a concise and elegant single line of

code written in BASIC for the Commodore 64 sometime in the early 1980s. When

run, it produces a maze-like pattern on the screen in an endless loop.



This is my port of that one-liner for the original Game Boy. Written in

assembly language using the RGBDS toolchain.



![](./10-print.gif)



> `10 PRINT` running on Commodore 64 (left) and Game Boy (right).



How comes is that?

------------------



[10 PRINT CHR$(205.5+RND(1)); : GOTO 10][10] is not only a witty one-liner but

also the title of a book. With the short program as the lowest common

denominator, the authors delve into diverse subjects like the Commodore 64,

maze in culture, and randomness in computing and art.



As I read the book and learned about `10 PRINT`, I thought that porting it to

the Game Boy would be a good learning experience and fun challenge. Not a

trivial one, though, as the Game Boy lacks some of the luxuries the Commodore 64

has through its KERNAL operating system and BASIC programming language.



I hope that you, fellow reader, will learn something as well or just have a

good time playing around with `10 PRINT`.



Watch it on a Game Boy

----------------------



Wanna watch the mesmerizing maze for real? Sure thing! Just download the

[preassembled ROM][rom], copy it over to a [flash cartridge][flash] and boot it

up using your Game Boy. You can also load the ROM in your favorite emulator or

[watch `10 PRINT` in your browser][browser].



![](./game-boy.jpg)



> The ROM should run on all hardware from the original Game Boy to Game Boy Advance SP.



Study the source

----------------



Do you want to take a peek behind the curtains? I'm glad to hear that! There's

an [annotated version][asrc] of the source code that's easy to read on GitHub.

Give it a shot – if it's not your thing you can always read the

[plain assembly version][src].



### New to assembly language and low-level programming?



Then you may want to catch up on the basics, before reading the source. A

favorite book of mine and its associated web course has you covered:

[The Elements of Computing Systems][book] and [NAND2Tetris][n2t]. Another great

resource is [Easy 6502][e65] - an e-book that shows how to get started with

6502 assembly language.



Assemble using RGBDS...

-----------------------



To assemble the `10 PRINT` Game Boy ROM, you'll need the assembler, linker and

fixer tools provided by the Rednex Game Boy Development System or RGBDS for

short. Go ahead and [install RGBDS][rgbds] on your system and come back here

when you're ready.



### ...and `make`



If you are on a \*nixy system, like macOS or Ubuntu, and have Make installed,

you should be able to run `make 10-print.gb` in the root of this directory and

see *10-print.gb* appear before your eyes.



### ...by hand



If Make is not your cup of tea, you can always do things the manual way. There

are three steps to assemble a ROM from source: assembling, linking and fixing.



You should be able to build *10-print.gb* by the following steps:



```sh

rgbasm -E -v -o "10-print.o" "10-print.asm"

rgblink -d -t -n "10-print.sym" -m "10-print.map" -o "10-print.gb" "10-print.o"

rgbfix -j -p 0x0 -t "10 PRINT" -v "10-print.gb"

```



License

-------



Licensed under the [MIT License][mit] – Copyright © 2018 Sven Dahlstrand.



[rgbds]: https://github.com/rednex/rgbds#1-installing-rgbds

[asrc]: ./10-pretty.md

[src]: ./10-print.asm

[rom]: https://github.com/svendahlstrand/10-print-game-boy/releases/download/v0x02/10-print.gb

[10]: http://10print.org

[asm]: #assembling-with-rgbds

[browser]: https://svendahlstrand.github.io/10-print-game-boy/

[make]: ./Makefile

[flash]: https://www.reddit.com/r/flashcarts/comments/6u7fuu/which_flashcart_do_i_want_start_here/

[n2t]: http://nand2tetris.org

[book]: http://nand2tetris.org/book.php

[e65]: https://skilldrick.github.io/easy6502/

[mit]: ./LICENSE