ROM padding question

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matteus
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ROM padding question

Post by matteus » Thu Aug 17, 2017 9:04 am

My Sonic Mania FMV ROM is 4,096KB. I removed 10 216x120 images of black from the ROM and the size was still 4,096KB is there any way of knowing what the true size is and how much space I have left? I'd like to try and squeeze a VGM file in if I can :D

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Stef
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Re: ROM padding question

Post by Stef » Thu Aug 17, 2017 9:24 am

Using an hexa editor to see how much 0 filled space you have at the end ? :p

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Re: ROM padding question

Post by matteus » Thu Aug 17, 2017 9:28 am

Stef... really now lol I'm crap at that stuff :D lol okay what hex editor should I use? :)

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Stef
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Re: ROM padding question

Post by Stef » Thu Aug 17, 2017 10:12 am

Whatever free hexa editor should do the job, myself i'm using FrHed :)

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Re: ROM padding question

Post by matteus » Thu Aug 17, 2017 1:39 pm

From Address 003ee4e0 to 00effff0 its nothing but "00"

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Staffan
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Re: ROM padding question

Post by Staffan » Thu Aug 17, 2017 7:22 pm

Just google "html5 hex editor", and you get a browser version. I used it to reverse engineer the old ansi bbs image protocol. 🙂. You can just drag the file you want to open to your browser.

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Sik
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Re: ROM padding question

Post by Sik » Thu Aug 17, 2017 8:30 pm

matteus wrote:
Thu Aug 17, 2017 1:39 pm
From Address 003ee4e0 to 00effff0 its nothing but "00"
The end of the ROM should be 003FFFFF =P
Sik is pronounced as "seek", not as "sick".

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HardWareMan
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Re: ROM padding question

Post by HardWareMan » Thu Aug 17, 2017 8:40 pm

Sik wrote:
Thu Aug 17, 2017 8:30 pm
matteus wrote:
Thu Aug 17, 2017 1:39 pm
From Address 003ee4e0 to 00effff0 its nothing but "00"
The end of the ROM should be 003FFFFF =P
The ROM windows should be $000000-$3FFFFF, but ROM itself not required to be up to $3FFFFF.

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Sik
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Re: ROM padding question

Post by Sik » Thu Aug 17, 2017 9:10 pm

It's a padded ROM. And the issue was going up to $EFFFFF which is definitely way beyond ROM area. Something went wrong there.

I'm assuming the actual padding is from $3EE4E0 to $3FFFFF.
Sik is pronounced as "seek", not as "sick".

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Re: ROM padding question

Post by matteus » Thu Aug 17, 2017 10:05 pm

Sorry TYPO! last address in the ROM file is 003ffff0. I know zero about hex and ROM addresses so feel free to give me a bit of an education in them!

So addresses $3EE80 to $3FFFF0

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Re: ROM padding question

Post by matteus » Thu Aug 17, 2017 10:13 pm

Okay I was using the HEX editor in Notepad++ which clearly isn't that great! Now download Frhed :)

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Re: ROM padding question

Post by Manveru » Fri Aug 18, 2017 6:49 am

In the makefile the rom is aligned according to a value.
SGDK size is 128kb: out/rom.bin -sizealign 131072
You can remove that alignment or reduce it to see where you are.
The man who moves a mountain begins by carrying away small stones. Confucius, 551-479 BC

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Stef
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Re: ROM padding question

Post by Stef » Fri Aug 18, 2017 11:28 am

ROM padding is here for some reason though, unpadded ROM won't work on some flash cart.

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Re: ROM padding question

Post by Manveru » Fri Aug 18, 2017 1:58 pm

yeah i know, but is a good way to know the real size of a game rom.
The man who moves a mountain begins by carrying away small stones. Confucius, 551-479 BC

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Re: ROM padding question

Post by cero » Fri Aug 18, 2017 5:59 pm

size -t *.o

The totals dec field will be very close to the used ROM size.

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