Hello,
I love to play my favorite games on original hardware. So far I successfully built one translated cart. I am in the process of doing a second one.
I am trying to build a cart with a translation of Akira (Famicom).
From what I see, the games has one PRG rom and two CHR rom:
http://bootgod.dyndns.org:7777/profile.php?id=1561
Orignal roms are as follows:
PRG0 - 128K
CHR0 - 128K
CHR1 - 128K
The three roms are DIP-28
After patching the translation and then using readnes to split I get:
PRG - 256K
CHR - 256K
Luckily PRG will fit on a M27C512 as this is the maximum size on a DIP-28.
My question is what to do with the CHR ?
- How can I check if the patches alter CHR and make it needed to replace the original CHR rom ?
- Should I split the CHR in two and burn the two CHR rom ?
Many thanks!
Akira translated cart
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1. NO BLATANT PIRACY. This includes reproducing homebrew less than 10 years old, with the exception of free software.
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3. Be nice. See RFC 1855 if you aren't sure what this means.
Re: Akira translated cart
512 = kibit, not kiByte! If they genuinely expanded the PRG to 256KB, you'll have to use a 2 megabit 'PROM, which only comes in 32 pin.decoder_82 wrote: ↑Fri May 22, 2020 10:55 pm Luckily PRG will fit on a M27C512 as this is the maximum size on a DIP-28.
Use some program that can compare binary files, or can tell you the checksum / hash of said files.How can I check if the patches alter CHR and make it needed to replace the original CHR rom ?
The purpose of the 74'139 you see on the board is to allow the use of two 28 pin 128KiB ROMs: it both combines PPU A13 and PPU /RD (to generate CHR /OE) but also uses some banking output from the TC0190 to address both ROMs.Should I split the CHR in two and burn the two CHR rom ?
If you use a new 2 mega bit 'PROM for CHR, you don't need either of the CHR ROMs or 74'139.
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Re: Akira translated cart
Many thanks for the reply !
Thanks for pointing that, you are right.
Indeed SHA-256 are not the same so it is fair to assume I will need to replace the original CHR.
Do you mean I can remove from the PCB CHR1 and 74'139 ?
Re: Akira translated cart
If you use a new 2 megabit PROM for CHR, you must disable both ROMs (by whatever means - this could include tying /CE high, or removing a ROM entirely from the PCB, or removing the 74'139 and tying the /CE pin high from that side)decoder_82 wrote: ↑Fri May 22, 2020 11:52 pm Do you mean I can remove from the PCB CHR1 and 74'139 ?
You could also see if the patch changes only one half of the CHR, and if so, only replace one CHR ROM or the other.
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Re: Akira translated cart
Famirom will split roms to appropriate sizes. DL from here:
http://retro.angelfire.com/kingmercury/
Itll also give you the hash for the chr, you can compare translated vs original rom chrs to see if theyve changed. It wont do halves though, only the whole.
http://retro.angelfire.com/kingmercury/
Itll also give you the hash for the chr, you can compare translated vs original rom chrs to see if theyve changed. It wont do halves though, only the whole.
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Re: Akira translated cart
Thanks everyone for the reply.
I have checked and after split the two CHR files have different checksum.
I guess some trials and errors will be needed to make it work.
I have checked and after split the two CHR files have different checksum.
I guess some trials and errors will be needed to make it work.
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- Posts: 8
- Joined: Fri May 22, 2020 7:49 am
Re: Akira translated cart
Awesome I was searching for a post like this. This should indeed help.Ice Man wrote: ↑Sun May 24, 2020 4:49 am Or look here: http://forums.nesdev.com/viewtopic.php?f=28&t=14210