NES vs 7800

[Metal Ghost]

It stated that Max Cart size for the 7800 is 128K, while for the NES it's 512K. Is that true? Or is there more to the story than those simple figures?

 

Absolutely not true!

 

- First, in the lifetime of the 7800, Alien Brigade and Crossbow were 144K.

- Second, there have been 512K demos for the 7800 released more recently. Examples:

- A prototype 512K 7800 board has been found

- Games that never got kicked off like TIME LORDS were intended to be 512K

- On both the NES and 7800, the games still deal with data in much smaller chunks because that's all the 6502 can access at a time

- I think there's a couple NES games that are bigger than 512K.

 

 

Yea, I had seen the Stickman Chronicles on 7800 video and remembered that it was a 512K cart. But this console information I was reading, that stated max 7800 cart size was 128K and NES was 512K, I assumed it was referring to max size without bankswitching. But of course after reading all the great input from the community it looks like it was just plan incorrect.

[supercat]

What about VCS carts?

 

Until 2006, every bank-switched 2600 cartridge either used a custom ROM chip, a custom or semi-custom/programmable bank-switching chip, or else two or more chips in addition to the ROM (Tigervision 3F might have only used two; I think most required three). Toyshop Trouble is an 8K game for the 2600 that uses a PROM plus one standard 74xx chip to control both banking and chip-select.

[gdement]

AFAICT,

 

Zelda 1 = 128 KB

SMB 1 = 40 KB

SMB 2J = 72 KB

SMB 2 = 256 KB

SMB 3 = 384 KB

is that the size of the programs on the cart? that's astounding! just from a layman's perspective, I would think that games like Zelda which featured massive worlds would be measured in the megabytes... isn't civ 3 for the PC something like 300 megabytes! I'm not at all disputing this data that usotsuki posted, I'm just saying it blows my mind how small these programs are!!!

 

 

The map compression used on popular NES games is pretty interesting. It generally depends on a hierarchy of data, building up bigger items from smaller units.

For example, the Legend of Zelda overworld defines 256 different vertical strips of tiles. Each of those would fill a single column of tiles on screen. There's a limited compression that reduces the bytes used for these. In the entire overworld, there are 256 possible arrangements of tiles in any column.

 

Then, 124 unique overworld screens are defined, each using only 16 bytes. Those 16 bytes reference the ID numbers of which prefabbed tile columns to use on that screen.

The overworld map is 128 bytes, each byte referencing one of those 124 unique screens (some screens are reused). There's another map for the 2nd quest.

 

End result is the entire overworld map data only takes a few KB to store on cartridge. The underworld is probably done in a similar way, and would take even less space since those screens are smaller.

If it ever seemed like the tiles in Zelda have a slightly repetitive arrangement, you're right, they do.

 

There's also some documentation online of the compression used in Kid Icarus and Metroid. I don't remember much about them but I do remember Metroid defines "screens", even though it's a scrolling game. The fact that you seem to run past screen-sized areas that look the same, isn't your imagination.