Are gameboy programs free

25 Antworten [Letzter Beitrag]
tomlukeywood
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Beigetreten: 12/05/2014

i have been doing some gameboy programming recently(good tutorials here)
and have learn that every program that runs on the game-boy(not including emulators)

must include the Nintendo logo in the ROM:

;* Nintendo scrolling logo
;* (Code won't work on a real GameBoy)
;* (if these lines are altered.)
 DB $CE,$ED,$66,$66,$CC,$0D,$00,$0B,$03,$73,$00,$83,$00,$0C,$00,$0D
 DB $00,$08,$11,$1F,$88,$89,$00,$0E,$DC,$CC,$6E,$E6,$DD,$DD,$D9,$99
 DB $BB,$BB,$67,$63,$6E,$0E,$EC,$CC,$DD,$DC,$99,$9F,$BB,$B9,$33,$3E

this means Nintendo effectively own the ROM and can decide who can make copy’s of it

of course you could just distribute the source code without the Nintendo logo and then
get people to run it in a emulator or include the Nintendo logo themselves

but do people here think Nintendo could infact stop you distributing a game-boy program
based on 48 bytes of data they forced you to include?

are there not anti monopoly laws in some countries?

onpon4
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Beigetreten: 05/30/2012

Yes, they could, with trademark law, since putting the logo in front sort of suggests an endorsement by Nintendo. This may have been what Nintendo was thinking: making it impossible to put games not endorsed by Nintendo on the Gameboy.

JadedCtrl
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Beigetreten: 08/11/2014

Perhaps you could add something that says "This game is not affiliated, endorsed, nor licensed by Nintendo."
Didn't the GameShark or Action Replay do that? My memory's rather horrid...

tomlukeywood
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Beigetreten: 12/05/2014

its impossible to put anything else next to the nintedo logo while its scrolling for a few seconds when you turn on the machine

so you would have to put any kind of message imediately afterwards

JadedCtrl
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Beigetreten: 08/11/2014

Yea, that's what the homebrews I've played do.

tomlukeywood
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Beigetreten: 12/05/2014

some decent ones (free as in freedom):
https://github.com/Sanqui/2048-gb
https://github.com/AntonioND/back-to-color

wish there were more though
but gbz80 assembler is hard O.O!

onpon4
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Beigetreten: 05/30/2012

Why would you want to use an assembly language for outdated, limited hardware that you're not even really targeting when you can use a modern language that's much easier and gives you much more options?

JadedCtrl
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Beigetreten: 08/11/2014

There's a rush you get, running a new program on an old friend you've shared so many memories with. =w=

tomlukeywood
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Beigetreten: 12/05/2014

1.
i am trying to learn an assembler language and gbz80 assembler is easier than x86 assembler
2.
its fun to try and make such limited hardware do cool things
and interesting to learn about the system in detail
3.
i love the gameboy!(nostalgia)

andermetalsh
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Beigetreten: 01/04/2013

" i am trying to learn an assembler language and gbz80 assembler is easier than x86 assembler"

Ditto, but with the ZX Speccy instead of the GB. Hardware initialisation on the GB is difficult.

Legimet
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Beigetreten: 12/10/2013

Assembly is fun, so why not?

tomlukeywood
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Beigetreten: 12/05/2014

no its not O.O!

andermetalsh
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Beigetreten: 01/04/2013

Is not as difficult as you think. There even homebrew games with the full source code available.

Like "Los amores de Brunilda". The game is available in English, too.

andermetalsh
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Beigetreten: 01/04/2013

z80 is really easy.

I don't think there is much change between coding for the ZX Spectrum and the Game Boy.

tomlukeywood
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Beigetreten: 12/05/2014

ok well its my first assembler language
do you know any good tutorials?

andermetalsh
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Beigetreten: 01/04/2013

I have a really good book but it's in Spanish :|

You have a lot of books in English on developing for the ZX Spectrum.

http://www.worldofspectrum.org/books.html

I use pasmo to compile the tap files (pasmo --tapbas file.asm file.tap ).

I run the tap files on FUSE-emu.

For Trisquel users, OpenSE is a libre boot basic ROM for FUSE.

pizzaiolo
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Beigetreten: 03/12/2015

Hm. I would also be interested in knowing whether these games can be seen as free or nonfree.

tomlukeywood
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Beigetreten: 12/05/2014

i have this cartridge(useable with free software):
http://store.kitsch-bent.com/product/usb-64m-smart-card

which shows the Nintendo logo when it starts up and i doubt Nintendo would allow it

so maby they just don’t enforce it anymore?

JadedCtrl
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Beigetreten: 08/11/2014

They really don't care anymore.
Quick question tom-- does that cart only support GB ROMs, or does it support GBC ROMs, like the 2048 program you linked to earlier?

tomlukeywood
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Beigetreten: 12/05/2014

GB and GBC

tomlukeywood
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Beigetreten: 12/05/2014

well anyway enjoy a crappy counter program!
(compiled with RGBDS assembler)

AnhangGröße
Counter.tar.xz 16.45 KB
andermetalsh
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Beigetreten: 01/04/2013

You don't have LDIR on the GB's z80 clone?

tomlukeywood
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Beigetreten: 12/05/2014

i haven’t seen it in any tutorials
what dose LDIR do?

andermetalsh
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Beigetreten: 01/04/2013

Copies DE into HL (well, this way you can point HL into memory), INCreases DE and HL, DECrements BC. If BC < 0, stops.
http://z80-heaven.wikidot.com/instructions-set:ldir
Useful to move sprites.

tomlukeywood
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Beigetreten: 12/05/2014

and now i made have a half decent game-boy tile editor!:

requires lua5.2 and the LuaSDL2 Libary

to start the program just use lua5.2 main.lua providing you have lua5.2 and luasdl2 installed

Scroll wheel to Select different Colours
Left Mouse to Paint a Pixel
Right Mouse to Set a Pixel to White

The Program writes the tile data to a file constantly
so when your finished just exit the program and the
file will have your tile data

This File(./OutputTile.asm) is in the same directory as the Tile program

and you can then just include it in your RGBDS Gameboy Program

if you want the program to start fullscreen run it like so
lua main.lua FULLSCREEN

Screenshot from 2015-08-21 18:35:01.png
AnhangGröße
TGBTE.tar.xz 27.59 KB
tomlukeywood
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Beigetreten: 12/05/2014

to add to this
someone has just made a free software(MIT) video player for the gameboy color!:
https://github.com/LIJI32/GBVideoPlayer/
https://www.youtube.com/watch?v=c5HfmaDCVsY