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Sega CD


floodie

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hi Guys - Any Sega CD experts in here?. I load a game and it seems to be an old school CD / jukebox loader screen instead of loading the game.

Few things if it helps, I have 3x Bios files in the System directory, and the Games are in the form of CHD's

Any input would really be appreciated thank you

David

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8 minutes ago, floodie said:

hi Guys - Any Sega CD experts in here?. I load a game and it seems to be an old school CD / jukebox loader screen instead of loading the game.

Few things if it helps, I have 3x Bios files in the System directory, and the Games are in the form of CHD's

Any input would really be appreciated thank you

David

What emulator are you using? Do the games work in the emulator by themselves not using Launchbox?

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16 minutes ago, floodie said:

Hey Neil - So i am using Retroarch, and the Genesis Plus GX core (i believe). When i launch Retroarch outside of bigbox the same thing happens.. Just loads the Music player intro thing.

Sounds like your roms are bad then. Sounds like your bios is good as i believe that is what you are seeing at launch. I guess it could also be that Retroarch is only seeing one bios file and the games you are testing are for a different region. Can you load the core by itself, go to information/core info and see if retroarch is seeing your bios files correctly.

 

 

Screenshot (411).png

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1 minute ago, floodie said:

So i have gone in there and looks like all 3 Sega CD bios are there and seen fine... is that what you meant?

IMG_20200316_151758_resized_20200316_031821727.jpg

Yeah, so that all looks correct. So my guess is bad roms at this point if they wont even load in Retroarch itself. I would try another emulator as well just in case though. ASll my Mega CD games are in CHD format and work just fine in Retroarch.

526010948_RetroArchScreenshot2020_03.16-15_28_49_09.thumb.png.91baaded799131e4d5728c9ba2deec0a.pngI do notice you are using a very old version of Retroarch, maybe thats a issue? Also in the image you just posted does it list CHD as a supported format? Your image is cut off there, maybe they werent supported that far back and you need to update the core/Retroarch?

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Neil : Thanks, so if i update retroarch will all settings remain the same?.. i dont really like Retroarch and its been a real walk through treakle getting it the way i want it and i would just not want to risk messing any of that up.. however if i can update RA and the core without any worry then ill give that a whirl mate..... Also you asked if it lists CHDs as a supported format, if i go back to that screen i was on and scroll down are you saying it will tell me?

Fromlostdays : You think its the bios do you?. So apart from region bios's there are different versions of each one?. ... 

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Just off a quick search can see some entirely different named Sega CD Bios's exist.. For Eg "us_scd1_9210.bin" - perhaps if i popped these in my system folder they may work.. There is a US, JAP, and EU version

EDIT: Ah these seem to be for the picodrive core i believe

Edited by floodie
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@floodieYou might check the CRCs of the bios files you have.  Some of the cores check only the name, others check the CRC.  The master CRC database is here

 

    comment "Sega - Mega CD - Sega CD""
	rom ( name bios_CD_E.bin size 131072 crc 529ac15a md5 e66fa1dc5820d254611fdcdba0662372 sha1 f891e0ea651e2232af0c5c4cb46a0cae2ee8f356 )
	rom ( name bios_CD_J.bin size 131072 crc 9d2da8f2 md5 278a9397d192149e84e820ac621a8edd sha1 4846f448160059a7da0215a5df12ca160f26dd69 )
	rom ( name bios_CD_U.bin size 131072 crc c6d10268 md5 2efd74e3232ff260e371b99f84024f7f sha1 f4f315adcef9b8feb0364c21ab7f0eaf5457f3ed )
	
	comment "Sega - Mega Drive - Genesis"
	rom ( name areplay.bin size 32768 crc 95ff7c3e md5 a0028b3043f9d59ceeb03da5b073b30d sha1 1e0f246826be4ebc7b99bb3f9de7f1de347122e5 )
	rom ( name bios_MD.bin size 2048 crc 3f888cf4 md5 d3293ebaaa7f4eb2a6766b68a0fb4609 sha1 3f50b76b0529db7f79c396b5e808cc0786ffc311 )
	rom ( name ggenie.bin size 32768 crc 14dbce4a md5 e8af7fe115a75c849f6aab3701e7799b sha1 937e1878ebd104f489e6bdbc410a184f79f1144a )
	rom ( name rom.db size 17742 crc c94e8c8b md5 ff4a3572475236e859e3e9ac5c87d1f1 sha1 02c287d10da6de579af7a4ce73b134bbdf23c970 )
	rom ( name sk.bin size 2097152 crc 0658f691 md5 4ea493ea4e9f6c9ebfccbdb15110367e sha1 88d6499d874dcb5721ff58d76fe1b9af811192e3 )
	rom ( name sk2chip.bin size 262144 crc 4dcfd55c md5 b4e76e416b887f4e7413ba76fa735f16 sha1 70429f1d80503a0632f603bf762fe0bbaa881d22 )

 

Edited by sundogak
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@floodie

Basically, a CRC is a checksum number that helps you determine if the file is corrupted from that of the original file as well as it is a unique "fingerprint" for the original file (at least for purposes of this hobby).  For Retroarch, they have a database listing of CRCs that are known to work with the cores. 

How do you find the CRC?  Well lots of utilities exist but I use one called HashTab. It allows you to right click on the file and it has a tab in your Explorer indicating all the checksum values (CRC, MD5, SHA1).  So you right click on file (see snap below), look at the numbers it shows and compare to the I referenced and you can tell if you file is intact, and likely the correct version as the emulator expects. If so, than can rule out the issue there. 

With all that, verify that your bios you have is this below (for US Sega CD games):

bios_CD_U.bin size 131072 crc c6d10268

Like Neil9000, noted it is unlikely the bios since you are booting up (just not launching the game) but would get good to double check.  Also, that  us_scd1_9210.bin file is also likely suitable as the bios_CD_U.bin Just check as noted above and if so, can rename and put in System directory.

 

Capture.thumb.JPG.5c129bfe337d866a302e17da4b844df1.JPGLastly, I don't recall when they added CHD support to the core, but you should update your RA install (like Neil9000 mentioned) and the cores to make sure you have current version and eliminate that as a variable.  They now have a handy update all your cores feature built in which makes things much easier.  There were also some cores that couldn't read certain CHD files if they were in newer CHD format.  I don't recall if that was the case with this one.  So again, update will solve that as potential since Sega CD works fine on my RA install with 1.8.4. 

Just download the installer from RA site.  For most part it updates cleanly. But to make sure, backup your CFG files in your root of the Retroarch folder and I also backup the Config folder.  If you want to go back to older cores, then also backup your Cores folder.  I have never fried it during install/update, but have accidentally done so when I was messing with stuff so the backup came in handy then (particularly the CFG files).

Edited by sundogak
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Hi Sundogak - Ok so, this screen shot shows all the CRC32 for all 3 bios;..... I have copy pasted from your master database you posted above and seems like "J" is different, but the other two are correct.... ?? Is my J bios bad?.... why then do no games work if 2 of the other bios' are fine? perhaps they are all Jap games?

comment "Sega - Mega CD - Sega CD""
	rom ( name bios_CD_E.bin size 131072 crc 529ac15a md5 e66fa1dc5820d254611fdcdba0662372 sha1 f891e0ea651e2232af0c5c4cb46a0cae2ee8f356 )
	rom ( name bios_CD_J.bin size 131072 crc 9d2da8f2 md5 278a9397d192149e84e820ac621a8edd sha1 4846f448160059a7da0215a5df12ca160f26dd69 )
	rom ( name bios_CD_U.bin size 131072 crc c6d10268 md5 2efd74e3232ff260e371b99f84024f7f sha1 f4f315adcef9b8feb0364c21ab7f0eaf5457f3ed )

crc32.png

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2 minutes ago, floodie said:

no i havent - as yet... a little too scared to do so!... its a case of, what is worse - not having Sega CD, or all the work ive put into Retroarch being lost.... This not having Sega CD is the better of the worst cases haha

Download the latest version to a different place on your PC and try it there. You dont have to update it you can have as many retroarch folders as you like as its a just a zip file and can go anywhere.

 

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