Some games aren't loading

[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!

[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.

[Beeble]

Will look out for such a collection, thank you!

[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.

[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.

[kubbie]

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?

[emmadness]

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/

[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

[colonel panic]

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