I tried making a rom hack of NHL 95, but when I tried to play it, all I got was a black screen.

 

 

Help..?

 

 

THis is the file that gave me a black screen, with nothing loading.

SEGA 95 (W) [!].bin

Did you disable the checksum?

No..?

17 hours ago, kingraph said:

Did you disable the checksum?

I don't think so.

On 11/26/2017 at 6:11 PM, Jlnhlsegafan said:

I don't think so.

To fix the checksum, open the ROM in NOSE then save a new copy. NOSE will automatically remove the checksum.

If you already used NOSE, then there is some other problem, which could be very hard to fix, so you probably just need to start over. So, when working on ROMs, it's very important to make frequent copies/backups of your ROM so if you break something, you can revert to a recent copy from before the change that broke it.

UPDATE:

To manually remove the checksum in a hex editor:

OFFSET: 0690
OLD VALUE: 4E9B
NEW VALUE: 6004 

Game Genie "master code" that enables other codes to work:

ATDA-AA6T

 

1 minute ago, smozoma said:

To fix the checksum, open the ROM in NOSE then save a new copy. NOSE will automatically remove the checksum.

If you already used NOSE, then there is some other problem, which could be very hard to fix, so you probably just need to start over. So, when working on ROMs, it's very important to make frequent copies/backups of your ROM so if you break something, you can revert to a recent copy from before the change that broke it.

NOSE never loads for me- even when using Wine.

1 minute ago, Jlnhlsegafan said:

NOSE never loads for me- even when using Wine.

Try http://forum.nhl94.com/index.php?/topic/109-rom-hacking-ea-genesis-games

 

To do this manually, change the 6 bytes of data located at offset @000690 to 4E71 4E71 4E71.

I clicked on "Calculate Checksum" on my hex editor, and now it won't close.

 

 

Plus, it seems like that point doesn't exist.

54 minutes ago, Jlnhlsegafan said:

I clicked on "Calculate Checksum" on my hex editor, and now it won't close.

 

 

Plus, it seems like that point doesn't exist.

Don't use the hex editor checksum. You need to edit the ROM to remove the code that does the checksum verification.

The address 000690 definitely exists unless your ROM had most of its contents deleted somehow.. What's the file size of your ROM? it should be 2 MB (I think.. anyway, if your ROM doesn't have address 690 then it's under 2 kB)

The size is 2.1 MB, but I don't see address 000690. The closest I can see is 000006A2.

1 hour ago, Jlnhlsegafan said:

The size is 2.1 MB, but I don't see address 000690. The closest I can see is 000006A2.

 

See above, those are the values you want to change.

13 hours ago, Jlnhlsegafan said:

The size is 2.1 MB, but I don't see address 000690. The closest I can see is 000006A2.

You have to imagine that it's like a grid like this

 
   | 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
---+---------------------------------------------
00 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
10 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
20 | 00 00 AA 00 00 00 00 00 00 00 00 00 DD 00 00
30 | 00 00 00 00 BB 00 00 00 00 00 00 00 00 00 00
40 | 00 00 00 00 00 00 CC 00 00 00 00 00 00 00 00
50 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

The value AA is at the intersectoin of 20 and 03... add those and it's 23.

The value BB is at the intersectoin of 30 and 05... add those and it's 35.

The value DD is at the intersectoin of 20 and 0D... add those and it's 2D.

If the values down the left side are not ending in 0, then you need to try to resize your window so they end in 0, so the math is easier.

Or, there is probably an address indicator at the edge of the window somewhere.

Or, check the menu of the program for a "go to address" option (usually Ctrl+G) and you can just enter the address you want to go to.

I can't find that value, sadly.

What was the hack? Perhaps you changed something you shouldn't have.

I replaced the entire Buffalo Sabres with Sonic the Hedgehog characters.

31 minutes ago, Jlnhlsegafan said:

I can't find that value, sadly.

I just opened the ROM you posted and it's there...  at address 00000690, the bytes are 4E B9 00 1A 72 C0, which you should replace with 4E 71 4E 71 4E 71.

Can you be more specific about what you are doing? A screenshot of your hex editor maybe?

(The values in my previous example were just examples to try to help you understand how to find addresses in a hex editor, they were not real contents of the ROM.)

This is my editor.

16 minutes ago, Jlnhlsegafan said:

Ah, ok. For some reason your editor is set up to show the addresses in decimal values, not hexadecimal.  000690 in hex is 1680 in decimal, so look for the 1680 row (but i recommend changing the settings to hex afterwards since we pretty much always post the addresses (aka offsets) in hex).

Changing it to hex is not an option in the editor.

1 hour ago, Jlnhlsegafan said:

Changing it to hex is not an option in the editor.

Can't help there, but you can just convert any hex values you find on the forums to decimal.

Other option is to use a different hex editor.  I like HxD -https://mh-nexus.de/en/hxd/  - it's free, and works fine for what I need.

The sad reality with me...

Were you able to make the change by using address/row 1680(decimal)?

The bytes "E B9 00 1A 72 C0" don't exist at that spot.

18 minutes ago, Jlnhlsegafan said:

The bytes "E B9 00 1A 72 C0" don't exist at that spot.

Send a screenshot of what you see there.  You are either in the wrong spot or have the incorrect ROM.

1 hour ago, Jlnhlsegafan said:

On second look, the bytes are off.  4EB9 should be at 1680, not 1682, which is per your screenshot.  You must have changed some data, which would be a bigger problem than just the checksum.  Best to look at the original '95 ROM, and not the one you modded.

But 4EB9 IS at 1680.