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Author Topic: A question about sprites in ROMs.  (Read 3940 times)

TheWhipperSnapper

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A question about sprites in ROMs.
« on: August 25, 2012, 11:10:11 am »
I have noticed that in some games the sprites for certain characters are in the rom multiple times. I.E.

Simon's Quest, Zelda II, Ninja Gaiden all have the main character frames: Simon, Link and Ryu in the ROMs image at
multiple locations using space unnecessarily.

But in games:
Castlevania I and III, Ninja Gaiden II and III, Megaman and even in the dreadful Dr. Jeckyll and Mr. Hyde
you only find the playable character animations once.

I find that confusing. Some of these games are linear platforms and others are adventure games but all things
being equal I don't understand the reason why they are set up like that.

henke37

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Re: A question about sprites in ROMs.
« Reply #1 on: August 25, 2012, 01:21:32 pm »
Laziness

ETG

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Re: A question about sprites in ROMs.
« Reply #2 on: August 25, 2012, 02:05:09 pm »
I know Zelda 2 was origianaly on the FDS, which used disk based games. It's much faster to load data onto ram in one big chunk than it is to move the head back and forth reading bits of data here and there.


Bregalad

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Re: A question about sprites in ROMs.
« Reply #3 on: August 25, 2012, 02:33:20 pm »
No, it's not laziness.

The mentioned games use the MMC1 mapper which can only switch CHR-ROM pages in 4kb units. All enemies of the game + the player apparently didn't fit a single 4kb page, therefore they needed to use multiple pages for different sets of enemies, the player's graphics staying constantly here, present on all pages.

I haven't checked but I'm pretty sure the FDS version of Zelda II only have the set a single time, he's talking about the cartridge version.

TheWhipperSnapper

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Re: A question about sprites in ROMs.
« Reply #4 on: August 25, 2012, 04:55:40 pm »
Zelda II FDS version has no VROM. It looks like there is only one page for Link's frames.

Question. Is there a program out there that can modify a ROM image so that games with no VROM can have graphics pages that are more easy to extract and edit, you know games like Castlevania where the graphics are scrambled and intermingled with other parts of the ROM?

Other question. Would it be at all possible to make a NES ROM the size of Dragon Warrior 4 (1024 kb) as a side scrolling adventure game or does the system have limitations on how big a platforming game it can handle?
« Last Edit: August 25, 2012, 05:16:48 pm by TheWhipperSnapper »

Bregalad

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Re: A question about sprites in ROMs.
« Reply #5 on: August 25, 2012, 05:52:30 pm »
Answer 1 : Yes - a tile editor.

Answer 2 : Dragon Warrior 4 is 512kb, and yes there is limitations on how bigs games can be, depending on the mapper. Those limitations are a bit complex, you should check ish's documents.

TheWhipperSnapper

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Re: A question about sprites in ROMs.
« Reply #6 on: August 25, 2012, 07:37:56 pm »
Answer 1 : Yes - a tile editor.

Answer 2 : Dragon Warrior 4 is 512kb, and yes there is limitations on how bigs games can be, depending on the mapper. Those limitations are a bit complex, you should check ish's documents.
No disrespect but....

Reply to Answer 1. Zelda II FDS version has no VROM. It looks like there is only one page for Link's frames. How do you think I came to that conclusion? I have Tile Layer Pro and Tile Molester. I probably should have mentioned that. All the same ripping graphics from non VROM games seems like a pain in the ass and I am not into making snapshots and ripping graphics that way. There must be an easier way.

Reply to Answer 2. I looked at the size of the Dragon Warrior 4 rom and it said 1024 kb.

Azkadellia

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Re: A question about sprites in ROMs.
« Reply #7 on: August 25, 2012, 07:51:17 pm »
A good Dragon Warrior 4 dump is 512K. The 1024K ROM is hacked to work on NESticle.
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danke

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Re: A question about sprites in ROMs.
« Reply #8 on: August 25, 2012, 08:18:01 pm »
No disrespect but....

Reply to Answer 1. Zelda II FDS version has no VROM. It looks like there is only one page for Link's frames. How do you think I came to that conclusion? I have Tile Layer Pro and Tile Molester. I probably should have mentioned that. All the same ripping graphics from non VROM games seems like a pain in the ass and I am not into making snapshots and ripping graphics that way. There must be an easier way.

I'm not sure what the problem is... The sprites are clearly viewable in YY-CHR. Even clearer if you switch to the FC/NES x 16 view. There are no programs out there that will magically layout all the sprites for you, since the programs have no idea what order the tiles go in.

Also, I'm not sure what you mean by "VROM"... Pretty sure you pulled that term out of thin air. The NES uses CHR-ROM, and the FDS doesn't really use ROM at all, CHR or otherwise. The graphics in the (Zelda 2) FDS image are laid out in a standard NES format and are easily accessible and viewable.

KingMike

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Re: A question about sprites in ROMs.
« Reply #9 on: August 25, 2012, 08:48:36 pm »
A good Dragon Warrior 4 dump is 512K. The 1024K ROM is hacked to work on NESticle.

Actually, it's not that it was hacked to Nesticle, but that Nesticle supported it before it was known to be a bad dump (by which point Nesticle was dead).

The FDS loads files from the disk into its PRG-RAM and CHR-RAM. So the graphics data will be in the same format as the cart because the FDS disks are just an alternate storage medium.
The only ROM the FDS uses is the BIOS ROM, which contains some functions (like reading the controller or turning the screen on or off) that games might use to conserve PRG-RAM.
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TheWhipperSnapper

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Re: A question about sprites in ROMs.
« Reply #10 on: August 25, 2012, 10:24:22 pm »
I'm not sure what the problem is... The sprites are clearly viewable in YY-CHR. Even clearer if you switch to the FC/NES x 16 view. There are no programs out there that will magically layout all the sprites for you, since the programs have no idea what order the tiles go in.

Also, I'm not sure what you mean by "VROM"... Pretty sure you pulled that term out of thin air. The NES uses CHR-ROM, and the FDS doesn't really use ROM at all, CHR or otherwise. The graphics in the (Zelda 2) FDS image are laid out in a standard NES format and are easily accessible and viewable.

http://www.nintendoplayer.com/database/info/emulation/doc/romdoc.html#graphics

VROM stands for video rom. However I will say this. I made a mistake. I do not know if those games have no video ROM except for Castlevania. Zelda II (J) I am not sure.

KingMike

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Re: A question about sprites in ROMs.
« Reply #11 on: August 26, 2012, 01:40:23 am »
CHR-ROM and VROM are two terms for the same thing. (a ROM chip in the cartridge that is directly accessed by the PPU to read tile data)

Zelda II for FDS is a magnetic disk. By definition it cannot have ROM. :)
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