#7 Various doubts and possible feature requests



Firstly, it seems impossible to contact the developer, post your contact man :P.

Second, this thread won't look as a 'Bug' or a 'Feature request', but I had to choose a category and it seems that this is the only way to have a contact with the developer. So let's start it.

Starting with something that I guess the developer shouldn't worry, but someone may know and help me. It seems CrabEmu doesn't run in any Dreamcast emulator to date. Then I tested burning a disc, but did some error while attaching an ip.bin and it didn't work on the actual machine. Now I am 'almost' sure everything is correct, but as it does not run in the emulators, I am afraid of wasting another disc. So just to confirm, am I doing something wrong and it does run on the emulators or I can burn and it will work fine?

Now I have some doubts, does CrabEmu support these things:
-Folder navigation (separate roms into different folders)
-Recognition and uncompression of zip files (i.e. can I store roms in zip files?)
-Files with a not known rom extension (.sms, .nes etc)

For the first two, if the answer is no, then there are 2 feature requests.

Thank you.


  • CG R
    CG R

    Just saw there were 6 tickets already. Nevermind the my 2 first doubts, I guess it's already been implemented, right?

  • You can always contact any member of sourceforge by going to their user page and sending them a message that way. This works too though. ;-)

    As for running CrabEmu in an emulator, I've certainly never tried to do that myself, so I dunno whether or not it works. I know that someone said that the menu didn't work right in NullDC a while back, but I think that issue had been corrected. As I said, I haven't tried myself, so I dunno what to suggest there...

    Directory navigation is indeed in the last released version of CrabEmu for the Dreamcast, as is zipped rom support. For zipped roms, the emulator will load whatever the first rom is that it finds in the zip file (so only put one rom in each). It should ignore any text files or anything that doesn't have a reasonable extension when parsing zip files. You can also gzip or bzip2 compress roms and that will also work (just compress the rom -- don't tar it or anything else).

    As for the third item, there's really not any reasonable way to determine what type of file you're trying to open except for looking at the extension, so it will only recognize files that have a recognized extension. SMS roms should be .sms, Game Gear games should be .gg, SC-3000 roms should be .sc, SG-1000 roms should be .sg, ColecoVision roms can be either .rom or .col, and NES roms should be .nes. Of course, all of these will also be recognized inside compressed archives as well.

  • CG R
    CG R

    Hello my friend, thank you for answer.

    Well, if someone else had errors, then it means the problem is in the emulator. This means they need to improve their Dreamcast emulation, as the actual machine can run your code.

    I will share my experience with the emulators:
    -NullDC 1.0.4 r136: Goes black screen after SEGA logo and then freezes.
    -Demul 0.58: Goes black screen after SEGA logo and then freezes.
    -Demul 0.581: Random crash while loading.
    -Chankast (yeah, this old thing): Freezes on sega logo.

    I will try to burn another disc and see if the error is mine and post the results:)

    Thank you.

  • CG R
    CG R


    The error is definitely mine. Apologizes to the emulator developers (NullDC at least). I am getting the same result in the Dreamcast (black screen). Wonder what I am doing wrong...

    I am using a simple tool called 'makeip' to fastly make an IP.BIN.
    Then I am using an automated tool ('Selfboot Inducer', that runs other tools in the background) just to make the iso file with the CrabEmu files (it's files, it's 1st_read.bin, roms, and the ip.bin I created with 'makeip') and export as .cdi (I am not using files that can be generated with 'Selfboot Inducer', just using as an "image maker").

    Judging by all this, do I look to be making something wrong?

    Thank you.

  • Have you made sure that the files on the disc go in the correct directories with how you are making the image? If you put the disc in your PC and look at it, the 1ST_READ.BIN should be in the root of the CD, and there should be a crabemu directory that has everything else in it (the various .png files, any BIOS roms, and a roms directory).

    The only other thing I can think of off the top of my head is that the tool you're using to make the image is expecting a non-scrambled binary. The 1ST_READ.BIN file that's included in the binary release is already scrambled, so if the tool you're using expects something unscrambled, you'll need to unscramble it first (or look for an option to use a scrambled binary). Unfortunately, I don't use Windows at all, so I can't really comment on what tools do what things and in what way.

  • CG R
    CG R


    Yeah, I guess everything is correct, with the directories.
    I guess I tried literally everything. I don't know if 'Selfboot Inducer' expects a scrambled binary, but I tried another tool: 'BootDreams' and it even detects if the image is scrambled or not and scrambles it automatically if you choose to.

    I even tried descrambling the image and using the Utopia boot disc, no success again.

    And you know what? I downloaded and tested SMS Plus DC and it worked perfectly, which the following results:
    -nullDC - works, with random lock up
    -demul058 - worked perfectly
    -demul0581 - crashes after sega logo
    *Tested with Hokuto no Ken (Taiwan)

    Unfortunately, CrabEmu didn't work at all, goes black screen on emulators and the real system while SMS Plus DC works without mysteries...

    I don't want to sound disrespectful, but are you receiving positive feedback with CrabEmu for DC using the 1st_read.bin provided by you?

    Thank you very much.

  • I haven't had any reports, other than yours, of anyone having any issues with the binary I put out.

  • CG R
    CG R

    I have to find those guys and trade our images then. :P

    Any extra config I should be concerned of?
    The absence of some file in the disc image can cause the lock up?
    What screen shall I expect if I ever manage to get this working?
    Could the sdcard support be the pivot of the situation (as I don't use it and emulators wouldn't detect it correctly aswell, I guess)?

    Thank you.

    Edit: My directory structure, as follow:
    Edit2: Re-editing as my frst edit as poorly edited. My root directory contains:
    -Folders: crabemu, docs
    -Files: 1ST_READ.bin, IP.BIN, and text files as such: BUGS, CHANGELOG, COPYING and README

    The subfolder crabemu contains:
    -Folders: crabemu
    -Files: bios.gg, bios.sms

    The crabemu "subsubfolder" contains:
    -Folders: roms (all my zipped roms go here)
    -Files: crab.png, title.png

    Last edit: CG R 2013-09-18
  • There's no user-configurable stuff in the Dreamcast version of CrabEmu at all.

    The first thing you should see if the emulator boots is the title.png file (that is in the archive) on the screen -- or at least the top-left 640x480 of it.

    The SD Card support shouldn't cause problems on the hardware whether you have one or not. I don't think it should cause problems on emulators either, since it should just detect that you don't have one connected. I suppose that could cause issues on emulators if they are doing something odd with the serial port, but I don't think it should be a problem in general...

    EDIT: I just noticed you edited your post. If you have a crabemu directory inside another crabemu directory, that is wrong. I just noticed that is a bit wacky in the archive that I released, but the instructions in the README should still be correct... It should look like this:
    /crabemu/coleco.rom (if you want ColecoVision support)
    /crabemu/roms/ (and put roms in here, of course -- although, you can browse the disc to find them elsewhere)

    Last edit: Lawrence Sebald 2013-09-18
  • CG R
    CG R


    I see, thank you. Do you know someone/somewhere, or yourself could provide me a complete working disc image (without roms) to I to make comparisons with the ones I am generating?

    Thank you.

  • CG R
    CG R

    Yes, I tried removing the second crabemu subfolder before too, no success, I will try again though.

    *Edit: Yes, no success. Tried also running older versions, and had same results.

    Last edit: CG R 2013-09-18
  • CG R
    CG R

    One year later and I wanted to give CrabEmu for DC a second chance and... IT WORKED perfectly... I don't know what I were doing wrong though.

    Some bugs I've encountered:
    -ZIP support doesn't work very well, despite of this being slow, CrabEmu stops retrieving .zip files for some reason (I believe it happens once it finds a new extension). And once you change directory, .zip files aren't retrieved at all.

    -No .col (Coleco Vision rom) files show up in the list. The coleco.rom file loaded with no problems though.

    -[SMS] Shinobi (USA/JP) runs without sound.

    -[SMS] Bios with games won't run as desired, example: [BIOS] Alex Kidd in Miracle World (USA, Europe)

    That's it,
    Thank you!

  • Hrm... Not sure why the ZIP stuff wouldn't work. I'll take a look when I get a chance.

    ColecoVision roms should only show up in the list if you have the ColecoVision bios rom named correctly and in the right place on the disc, otherwise, since those roms would not work, they don't show up in the menu. If they aren't showing up, then there's something else I have to take a look at.

    BIOSes with games built in... Are you trying to run that as the BIOS itself, or are you trying to run it as a normal game rom? The latter might not work, due to the way that I actually implement support for the BIOS in the correct way. If it isn't working when set as the BIOS, then I suppose that's yet another thing I have to take a look at.

    As for the sound problem with Shinobi... Well, I'll address that in the bug report for that particular game, since you filed one of those too. ;-)

    • assigned_to: Lawrence Sebald
    • Group: Next_Release --> v0.2.1
  • Running the BIOS without loading a rom is now possible on the OS X version of CrabEmu, so I'll also work on bringing that feature to the Dreamcast version for the next release (whenever that will be). That'll probably also mean I'll be adding some configuration options (to configure the BIOS in use and such), but no promises there for now.

    I can also confirm that trying to run a BIOS as a normal game rom will most assuredly not work, so I'm guessing that's what you were trying to do. Running it in the OS X version with the new option works fine (with the Alex Kidd BIOS, by the way), so once I port the feature over, it should work fine in the Dreamcast version too.

  • CG R
    CG R

    Hello, thank you for the fast answers.

    About the Colecovision roms not showing up, I have coleco.rom in crabemu directory among the bios.gg and bios.sms. The content of the directory is like this:
    -roms\ -bios.gg

    in the roms directory I have another folder named "Colecovision" and all roms inside have the ".col" extension.

    I noticed you marked the "no sound" thing for shinobi as fixed, and by what you said, it should fix possible other games that try the same, right?

    Another thing about the .zip support is that it is extremely slow compared to "raw" files (not loading a game, but listing it). It isn't supposed to be that slow, is it?

    I also noticed many SG-1000 games won't boot, is this due a real SMS machine not capable of loading them all or is the implementation not "perfect"?

    Thank you!

  • The reason that listing zip files would take longer is that the code that displays the directory listing checks to see if the files in the directory are actually valid roms before showing them. That means with zip files that it has to actually look at each file within each zip to see if there's a rom in it.

    With regard to the ColecoVision thing, I'll have to take a better look at things at some point, as I said before. I don't really have an ETA to when that might happen though.

    With regard to the no sound thing, yes, that fix should probably fix other games that exhibit the same problem.

    Finally, I'd never be headstrong enough to claim that any of my code is "perfect", especially not any emulation-related code. There are always bugs to be found. If you have specific games that don't work, please file individual bug reports for them (one per game, please), and I'll take a look.

  • CG R
    CG R


    Wouldn't it be better to remove the file extension checkage, and only make some kind of check when user attempts to load a game? Feature request

    Would it be annoying if I opened a bug report for every single game that won't boot?

    Thank you!

  • That would work, but in my opinion, isn't quite as intuitive to the user. It probably is a relatively good idea though, since it can get quite slow if it has to check hundreds of zip files, I guess.

    As for the bug reports, I'd rather there were a bunch of them. It makes it easier for me to keep track of. Since I'd likely have to test each game individually, and might potentially have to make individual fixes for each game (hopefully it wouldn't come down to that, of course), it's easier if they are all separated out. I don't care about there being a bunch of open bugs -- just make sure to tell me what game isn't working, what region the game is for (although, if it is SG-1000, that'd all be Japanese, I suppose), and what exactly is wrong (if it boots to a black screen, say that). :)