Gameboy Development Forum

LIJI · 2015-08-27 16:24:17

Hey,

I created a big Gameboy Color demo, sized about 5MB, but I currently use a GB USB Smart Card 64m cartridge, which can only store 4MB ROMs.

I'm looking for a cartridge recommendation that can fit 8MB ROMs. The only one I can find is the Everdrive GB, which is quite an overkill (and expensive) for a single demo.

Further notes:

- Compression is not an option – I've actually proven I do not have enough "free" CPU cycles to implement any kind of decompression in this kind of demo.
- The GB smart card actually does have enough room for 8MBs of data, but the cartridge is split into two separate 4MB ROMs you can switch between. If anyone knows any cartridge-specific software hack to switch between the ROMs without restarting the Gameboy, this would be really helpful.
- Since I'm otherwise quite happy with my Smart Card, I'm simply looking for the cheapest 8MB-capable flash cart, assuming it doesn't suffer from any awful compatibility problems.

Thanks in advance!

a cat · 2015-08-27 18:29:46

Why not try find a GBA Flash cart and use that to load the ROM on a GBA
it should work the same on a GBA as it dose on a GBC

also
WOW 5MB!
must be a pretty awesome demo!
is the source code available?

Last edited by a cat (2015-08-27 18:30:24)

LIJI · 2015-08-27 18:43:03

Mmm, I actually do have a GBA flash cart for my DSL, but I don't have a GBA. I didn't know you could flash GB/C games on a GBA cartridge!

As for the demo and the source – since I believe my demo is quite unique and will probably be very interesting outside the GB development community, I'd first like to get the thing to run on a real GBC myself, and upload a video online before I share the sources (and reveal what the demo actually is! ). The code itself is quite short, but it uses a LOT of data (it reached 7MB before) and uses some pretty cool tricks I will explain in detail once the source is release.

Also, for the proposes of shooting the video, I'd rather to actually use a GBC and not a GBA, so I guess I'll leave the GBA as a last resort.

Thanks!

Jesse · 2015-08-29 05:31:29

Who actually decompresses stuff when the game is running? aren't you supposed to do that when you load a room for example? and then store it in ram?

LIJI · 2015-08-29 06:41:50

The game would have to decompress data from the ROM into the RAM. In my case however, I'm reading so many bytes of data very quickly, so there isn't enough CPU idle time left for me to do this (I've actually counted free cycles and micro optimized the code, and I still don't have enough)

Btw, about using a GBA flash cart – do these include a Gameboy MBC? Because it obviously won't work without one.

a cat · 2015-08-30 16:42:36

i have no idea

you may be better off buying a Ever-drive GB
as with the GBA option you would have to buy a GBA and GBA flash cart

so it may even be cheaper

LIJI · 2015-08-31 19:44:35

Well, here it is: a video player for the Gameboy Color!
https://www.youtube.com/watch?v=c5HfmaDCVsY

The ROM, source code, and an article explaining how it works can be found on GitHub: https://github.com/LIJI32/GBVideoPlayer/

a cat · 2015-09-01 06:15:00

Thats Amazing!
Thanks a lot for this!
now all we need is 256MB cartridges and the GBC Media industry will begin once more!

did you use the Everdrive GB?

also do you know what license your source code is under?

*if you dont have a license i recommend viewing this page:
http://choosealicense.com/

LIJI · 2015-09-01 06:41:13

Whoops, forgot adding a license! It's under the MIT license now.

And yeah, you could fit 25 minutes of video in a 256MB cart, and use OAMs for subtitles. Another cool thing to note is that you can reach full resolution by reducing the number of colors to 3/4 (without blur) or 10 (with blur) – perfect for black and white/greyscale videos. You can also double the resolution without losing color information (or increasing size!) by creating a more advanced encoder.

Eventually I worked around the 4MB limitation of my cart by actually splitting the video in two for sake of uploading to Youtube; I should probably add a proper disclosure.

a cat · 2015-09-01 08:07:05

would the program also run on the gameboy classic with some small modifications?

LIJI · 2015-09-01 08:20:01

Yes, but at half the resolution that would be possible on a Gameboy Color: 10 colors on 80x144, or 3 colors on full resolution with blur.

Edit: See https://github.com/LIJI32/GBVideoPlayer … 20Works.md

Last edited by LIJI (2015-09-01 08:22:49)

l0k1 · 2015-09-01 13:54:38

Wow that's amazing! Definitely going to be looking into your code.

Xephyr · 2015-09-03 18:29:59

That's really awesome, I wish I had the skill to do something like that x)

doragasu · 2015-09-04 08:07:08

Maybe you have found that by yourself, but you CANNOT load GB[C] ROMs on a GBA, using a GBA flash cart, unless you use some kind of adapter. Bus interfaces are different (GBA bus is multiplexed) and voltages are different (GB[C] carts run at 5 V while GBA games run at 3.3V).

Just to clarify: even though you can run GB[C] games on a GBA, a GBA flash cart cannot be used to load GB[C] games unless you use an adapter.

BTW nice demo!

LIJI · 2015-09-04 09:31:05

I see, makes sense. Well I guessed the lack of an MBC would probably already make it impossible, but seems like there's more to it.

Gameboy Development Forum

Ads

#1 2015-08-27 16:24:17

Need a cartridge to store a big (>4MB) demo

#2 2015-08-27 18:29:46

Re: Need a cartridge to store a big (>4MB) demo

#3 2015-08-27 18:43:03

Re: Need a cartridge to store a big (>4MB) demo

#4 2015-08-29 05:31:29

Re: Need a cartridge to store a big (>4MB) demo

#5 2015-08-29 06:41:50

Re: Need a cartridge to store a big (>4MB) demo

#6 2015-08-30 16:42:36

Re: Need a cartridge to store a big (>4MB) demo

#7 2015-08-31 19:44:35

Re: Need a cartridge to store a big (>4MB) demo

#8 2015-09-01 06:15:00

Re: Need a cartridge to store a big (>4MB) demo

#9 2015-09-01 06:41:13

Re: Need a cartridge to store a big (>4MB) demo

#10 2015-09-01 08:07:05

Re: Need a cartridge to store a big (>4MB) demo

#11 2015-09-01 08:20:01

Re: Need a cartridge to store a big (>4MB) demo

#12 2015-09-01 13:54:38

Re: Need a cartridge to store a big (>4MB) demo

#13 2015-09-03 18:29:59

Re: Need a cartridge to store a big (>4MB) demo

#14 2015-09-04 08:07:08

Re: Need a cartridge to store a big (>4MB) demo

#15 2015-09-04 09:31:05

Re: Need a cartridge to store a big (>4MB) demo

Board footer