View Full Version : Crc32 Error

September 29th, 2009, 23:20

I created the DC.zip file by first renaming my bios file to 1_01d_01.bin and then archiving my bios and flash files. When I tried to "Run DC", an error message popped up:


I recognize these codes from the dc.dat file on the main page, but how do I change them?

I'm running XP and the latest version of Demul


September 30th, 2009, 00:17
it looks like you may have misnamed files?

clrmamepro (
name "Dreamcast Bioses"
description "Dreamcast Bioses"
category "BIOS"
version 2008-03-01
author "DEmul team"
comment "no comments"

game (
name dc
description "dc"
rom ( name 1_004_01.bin size 2097152 crc 5454841f md5 37c921eb47532cae8fb70e5d987ce91c sha1 1ea132c0fbbf07ef76789eadc07908045c089bd6 )
rom ( name 1_011_01.bin size 2097152 crc 2186e0e5 md5 eafca1eed2d7f76c487e940597c2a786 sha1 6bd18fb83f8fdb56f1941e079580e5dd672a6dad )
rom ( name 1_01d_01.bin size 2097152 crc 89f2b1a1 md5 e10c53c2f8b90bab96ead2d368858623 sha1 8951d1bb219ab2ff8583033d2119c899cc81f18c )
rom ( name 1_01d_02.bin size 2097152 crc a2564fad md5 a5c6a00818f97c5e3e91569ee22416dc sha1 edc5d3d70a93c935703d26119b37731fd317d2bf )

September 30th, 2009, 23:56
Sorry, but reposting the dc.dat file that I've already seen doesn't help me because:

1. I have no idea what the dat file is and what to do with it. What is hashing files or whatever?

2. I downloaded the bios from an outside source, it was named dcboot.bin, and I renamed it as above because someone on this forum told me to do that

Do you make a bios file using that dat file? If so, how?

No offense, but I wish you guys would make this emulator more newbie-friendly

Thanks for the reply

October 1st, 2009, 00:57
1. Dc.dat is needed in Dc.zip that has to be located in Demuls rom folder. Dc.dat describes the BIOS files that can be used with Demul and their sizes and respective hash values (CRC, MD5 and SHA1) - consider those hash values to be not unlike fingerprints of sort.

2. That file you got is indeed a Dreamcast BIOS file, just not the right one for Demul. Whoever linked to the file didn't bother to check if the file matched to any of the entires in Demul's dc.dat. Demul is picky when it comes to the files you can use, while other emulators are not so picky.

You don't "make" BIOS files out of DAT files. More like DAT files are made based on the information within other files, be that BIOS files, romsets, or some other types of files or archives. DAT files are information repositories that describe that characteristics of a file or files.

October 1st, 2009, 17:53
My point was it looks like you renamed files incorrectly. from the dat:
name 1_004_01.bin crc 5454841f
name 1_01d_01.bin crc 89f2b1a1

Your file named 1_01d_01.bin looks like it is actually file 1_004_01.bin