Question about Cart space

[Metallica Man X]

Just wondering how much data can you fit onto say...

a NES cart
a SNES cart
a Genesis cart
or any other cart that's been made!

[palmertech]

Depends on the cart.

As a flash drive or something? Not really possible, using the original guts, at least.

[XCVG]

Depends on the cart.

As a flash drive or something? Not really possible, using the original guts, at least.

More like secret storage for secret files that must be hidden from the world, lest the conspiracy be discovered. It would play normally unless read by a special machine...

[eurddrue]

I'm pretty sure most n64 carts are 8 mb, but the mildy heavy ones are 16-32 and conkers bad fur day and resident evil are 64 mb

[palmertech]

Don't forget Pokemon Stadium 2, 64mb as well!

[Metallica Man X]

wow, 64 is all the N64 cart could hold? geez...that's piddly, lol. I wonder how weak the NES/SNES/Genesis carts are....

[nitro2k01]

(Note, B consistenly means bytes, not bits in this post, in case anyone is wondering)

There are two values to be considered.
1) How much cart space that can be directly addressed by the CPU.
2) How much can be addressed with standard mappers.
1 depends on the system's address bus. 8bit systems (Which generally have a 16-bit address bus) can address up to 64 kB of data. However, all memory has to fit into to that area. (Internal RAM, graphics RAM, IO registers) so typically, 1/2 or 1/4 of that space is available for cartridges. To solve this problem, a cartidge may contain a mapper which takes, say, a visible area of 16 kB and swap it to any 16 kB area of the total ROM. That way all data can be accessed, albeit not at the same time. (Like pages in a book)

For NES I'd estimate the standard sizes was in the range 32 kB - 256 kB with some commercial cartridges hitting 512 or maybe even 1024 kB. The biggest NES ROM I've seen is a HKO version (Honkong Original) of Final Fantasy 7, at a wobbling 2 MB.
About the same for Gameboy.

The two rivaling 16-bit systems (Gensis and SNES) did in fact have 24-bit address busses. Genesis had it directly through its 68k CPU, while the SNES had it though a weird segmented 8+16 bit addressing. Again, the full memory area is not directly available. I don't know the details for the SNES, but for the Genesis only 4 MB of the memory map (2 Mwords) is designated to the cartridge. I believe only 2 or so commercial games ever used memory mappers to increase the available ROM space. So the majority of Genesis carts are maximum 4 MB.

GBA has a 32 MB linear (Non-banked) memory space. I don't know if there are memory mappers for it GBA cartridges.

I'm guessing N64 has a completely linear cartridge memory space.

DS, as well as any disc based system must use a different method. The CPU can't execute code directly from the CD. Instead the data must be loaded into RAM and executed there. The same goes DS for cartridges which are using serial communication to transfer the data to RAM where it is then executed.

[marshallh]

I'm guessing N64 has a completely linear cartridge memory space.

DS, as well as any disc based system must use a different method. The CPU can't execute code directly from the CD. Instead the data must be loaded into RAM and executed there. The same goes DS for cartridges which are using serial communication to transfer the data to RAM where it is then executed.

N64 cartridges range from 4mbytes - 64mbytes and are treated as mass storage - the first 1 mb at the beginning of the rom. The CPU cannot actually access cart memory directly, it has to have the RCP DMA it into RDRAM. In this sense it's like a CD-ROM device more than anything. This is why the 64DD add-on is so electronically simple.

Very similar to the DS

[timmeh87]

I know perfect dark was 256 mbit... did they ever actually make a 512mb (64MB) n64 game?

[palmertech]

Pokemon Stadium 2.

And the others that people have already posted.

[eurddrue]

and conkers bad fur day and resident evil are 64 mb

[timmeh87]

Hey, why read entire one-page threads when I can just say whatever I want?