Vampier.net JP Boot ROM is an Overdump of the US Version

[Akuma]

So I just setup the core and was playing around with it, when I found out that the JP boot rom is an overdump.
Its identical to the US boot.rom

These are the sha1sums for the files:

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$ sha1sum *.rom
a749c815e858a2487f4105022d23e7001ee6f0ec  br.rom
15c23c3b671a8828302603f30c81d464b24a7fb1  eu.rom
9174eadc0f0ea2654c95fd941406ab46b9dc9bdd  jp.rom
b7a0070cbe4b9bcaa08ec0b76b8c4955b2ae535a  us.rom

These are the sizes:

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$ ls -l *.rom
-rwxr-xr-x 1 test test 1984 Jan  1  2000 br.rom
-rwxr-xr-x 1 test test 1984 Jan  1  2000 eu.rom
-rwxr-xr-x 1 test test 2048 Jan  1  2000 jp.rom
-rwxr-xr-x 1 test test 1984 Jan  1  2000 us.rom

As you can see the jp.rom is 2048 bytes long instead of 1984 bytes.
Examining those last bytes they do not contain any relevant data.

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hexdump -vC jp.rom

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000007d0  00 00 00 00 ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000007e0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000007f0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000800

Stripping the bytes from the jp.rom into jp_fixed.rom

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$ head -c1984 jp.rom >jp_fixed.rom

Gives us the sizes:

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$ ls -l *.rom
-rwxr-xr-x 1 test test 1984 Jan  1  2000 br.rom
-rwxr-xr-x 1 test test 1984 Jan  1  2000 eu.rom
-rw-r--r-- 1 test test 1984 Oct  6 20:19 jp_fixed.rom
-rwxr-xr-x 1 test test 2048 Jan  1  2000 jp.rom
-rwxr-xr-x 1 test test 1984 Jan  1  2000 us.rom

These are the sha1sums for the files, sorted by hash:

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$ sha1sum *.rom | sort
15c23c3b671a8828302603f30c81d464b24a7fb1  eu.rom
9174eadc0f0ea2654c95fd941406ab46b9dc9bdd  jp.rom
a749c815e858a2487f4105022d23e7001ee6f0ec  br.rom
b7a0070cbe4b9bcaa08ec0b76b8c4955b2ae535a  jp_fixed.rom
b7a0070cbe4b9bcaa08ec0b76b8c4955b2ae535a  us.rom

You can clearly see the jp_fixed.rom is identical to the us.rom

[Hectic]

The bios ur refering as JP is in fact the Aleck64 bios. The home jap and us bios are literally the same <[BIOS] Nintendo 64 - PIF (Japan, USA)>

vampier may want to change US for US/JP in that table to avoid future confusion.

[Akuma]

This is what it is now:

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Bios File Name	Region	Version		SHA1
boot.rom	US	NTSC 60hz	B7A0070CBE4B9BCAA08EC0B76B8C4955B2AE535A
boot1.rom	EU	PAL 50hz 	15C23C3B671A8828302603F30C81D464B24A7FB1
boot.rom	BR	PAL-M 60hz	A749C815E858A2487F4105022D23E7001EE6F0EC
boot.rom	JP	PAL 60hz (Aleck64)	9174EADC0F0EA2654C95FD941406AB46B9DC9BDD

This is what is should be:

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Bios File Name	Region	Version		SHA1
boot.rom	JP/US	NTSC 60hz	B7A0070CBE4B9BCAA08EC0B76B8C4955B2AE535A
boot1.rom	EU	PAL 50hz 	15C23C3B671A8828302603F30C81D464B24A7FB1
boot.rom	BR	PAL-M 60hz	A749C815E858A2487F4105022D23E7001EE6F0EC

The EU and the BR are almost identical, 2 bytes difference
17c17
. 000100 32 73 00 01 12 60 00 02 36 f7 00 06 3c 0b a6 00
. 000100 32 73 00 01 12 60 00 02 36 f7 00 04 3c 0b a6 00
19c19
. 000120 24 09 00 10 32 d6 00 ff 32 b5 00 01 24 14 00 00
. 000120 24 09 00 10 32 d6 00 ff 32 b5 00 01 24 14 00 02

As I see it now, you only need:

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boot.rom	JP/US	NTSC 60hz	B7A0070CBE4B9BCAA08EC0B76B8C4955B2AE535A
boot1.rom	EU	PAL 50hz 	15C23C3B671A8828302603F30C81D464B24A7FB1

The BR can easily be derived from the EU, by patching those 2 bytes in memory. (maybe it already does that)
Most likely one is a region identifier, the other for the video mode?

Conclusion:
The (Aleck64) is an overdump of the JP/US. The fact that there are only 3 PIF files and not 4
in the No-Intro Nintendo 64 pack seems to confirm that.

[Akuma]

And vampier.net update its site, yay!