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Some games aren't loading

Posted: Thu Jun 04, 2020 6:36 pm
by Beeble
Greetings,

I received 32MB RAM from a friend until my 128MB arrives and I wanted to play some good ol´NES, but many games arent loading.
While a few load fine (the little Mermaid (US), Ghostbusters (US), many load and then just give me a grey screen (Zelda 1+2, Junglebook, many more..)

I took the roms from my EverDrive N8 / Everdrive pack.

Thank you for your time!

Re: Some games aren't loading

Posted: Thu Jun 04, 2020 9:40 pm
by LeftEmpty
As a first move, in my experience, you should look up games with NES 2.0 headers. I had a bunch of issues with my older sets, almost all solved by starting to use such dumps.

Re: Some games aren't loading

Posted: Thu Jun 04, 2020 10:12 pm
by Beeble
Will look out for such a collection, thank you!

Re: Some games aren't loading

Posted: Thu Jun 04, 2020 11:03 pm
by ExCyber
This sort of thing can happen when ROMs are transferred over FTP in ASCII mode, or something else that does a similar conversion. For example, if converting newlines from DOS/Windows to Unix, ROMs that happen to contain the byte sequence "0D 0A" will be broken while those that don't contain that byte sequence will be fine.

Re: Some games aren´t loading

Posted: Thu Jun 04, 2020 11:38 pm
by Beeble
My dear ExCyber,

you are the man!

That actually did the trick and also fixed my bios issue I had with the TurboGrafx16-CD.

Thank you very much, was slowly going crazy on this.

Re: Some games aren't loading

Posted: Thu Jun 04, 2020 11:51 pm
by kubbie
LeftEmpty wrote: Thu Jun 04, 2020 9:40 pm As a first move, in my experience, you should look up games with NES 2.0 headers. I had a bunch of issues with my older sets, almost all solved by starting to use such dumps.
How can you tell if your game has NES 2.0 headers? is there a program that will tell you?

Re: Some games aren't loading

Posted: Fri Jun 05, 2020 12:55 am
by emmadness
kubbie wrote: Thu Jun 04, 2020 11:51 pm
LeftEmpty wrote: Thu Jun 04, 2020 9:40 pm As a first move, in my experience, you should look up games with NES 2.0 headers. I had a bunch of issues with my older sets, almost all solved by starting to use such dumps.
How can you tell if your game has NES 2.0 headers? is there a program that will tell you?
Check this:

NES Mapper Reader / Rom Fixer / Rom Splitter
Programmed by: Shawn M. Crawford [sleepy]
Last Update: February 19th, 2017
Latest Version: 2.0

https://www.romhacking.net/utilities/683/

Re: Some games aren't loading

Posted: Fri Jun 05, 2020 8:33 am
by mic_
Do you have a hex editor on your Mac?

You can tell if the file has an INES header or a NES 2.0 header by looking at the 8th byte in the file. If the least significant digit of that bytes is 8, 9, A or B, then it's a NES 2.0 header. Otherwise it's an INES header (assuming that the first 3 bytes of the file are 'N', 'E', 'S').

In an INES header, the mapper number is split between the 7th and 8th bytes, like this:

Code: Select all

File offset    Value        Meaning
------------------------------------
06             LLLLxxxx     Low 4 bits of mapper number
07             HHHHxxxx     High 4 bits of mapper number
So let's say the values of those two bytes are Ex, 4x (where x means "anything"). Then you're looking at mapper 4E, i.e. mapper 78.

In a NES 2.0 header, the mapper and submapper numbers are found in the 7th, 8th and 9th bytes:

Code: Select all

File offset    Value        Meaning
------------------------------------
06             LLLLxxxx     Low 4 bits of mapper number
07             MMMMxxxx     Mid 4 bits of mapper number
08             SSSSHHHH     Submapper number, and high 4 bits of mapper number

Re: Some games aren't loading

Posted: Wed Jun 10, 2020 11:16 pm
by colonel panic
Bits n Stuff wrote: Fri Jun 05, 2020 7:12 am Is there a way to find out/fix mappers on a Mac?
I haven't heavily used a Mac or Linux desktop in a few years (despite the pun that is my username) but in my experience most simple Windows programs like the one emmadness mentioned seem to work fine in WINE