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jmrydholm · Joined: 05 Apr 2005 Posts: 12 Location: Michigan

Hey all,
I'm getting a strange error message when I try to add certain rom files to the program list in DreamWriter. (This is for the 64MB MD-Pro cart) I get:

"Access violation at address 004CDF90 in module 'mdmtlk'.exe. Read of address FFFFFFFF."

A good example of the type of cart images that do this would be Ninja Turtles: Hyperstone Heist, Konami's Sunset Riders, and others. Is this some kinda protection? I tried various dumps on the two aforementioned games and they did not work. I tried another hacked dump of Castlevania: Bloodlines and that one works fine though. If I sould like a total idiot, mis-un-informed childlike midget, or the so called slang vernacular "noob, newb, newbie, etc." then I must apologize and kick my head through a nearby wall. Cool

Any info is appreciated.

Oh yeah and Tototek rules! I love this flash cart! My hat's off to Tomy and the rest of you. -John

deadscreem · Joined: 18 Mar 2005 Posts: 16

This happens because one of the names stored in the Genesis header is blank. (all spaces) By default Dreamwriter will use the name stored at 0x120. If the name at 0x120 is stored in Shift-JIS (japanese text) It tries to use the name at 0x150. And there is the problem. there are quite a few japanese games that have the first name stored in Shift-JIS than have the second name blank. And also alot of other games which have blank names in both. Dreamwriter needs a valid name to use for the menu.

To fix this you need to hack the ROM to add a english text name in the ROM header. YOu can use a hex editor like Hex-workshop. or one of the many genesis ROM header editors.

jmrydholm · Joined: 05 Apr 2005 Posts: 12 Location: Michigan

Ah, I see. So what causes the red screen of death? I copied Quackshot, TMNT:HH, and Rocket Knight but all I get is a red screen upon boot up on all of them. They all have name headers too under the menu. For some reason only the first 3 of my dumped ROMS work this time. maybe I'll reformat the flash cart and try again.

Tomy · Site Admin Joined: 02 Aug 2005 Posts: 414

jmrydholm,

"Access violation at address 004CDF90 in module 'mdmtlk'.exe. Read of address FFFFFFFF." mean something wrong when you run dreamwriter software. That is your windows problem or some setup problem. If md pro broken, something will like that :
1) Can not detect the cart
2) After flash games, verify error
Of course wrong cables also cause problem. You have red-screen mean checksum error from games. So, you don't have fully flash the games. That mean you need to flash game and verify without error. If you have "Access violation" error, of course you can not finish flash and verify. Please try another pc. Thanks.

deadscreem · Joined: 18 Mar 2005 Posts: 16

deadscreem · Joined: 18 Mar 2005 Posts: 16

SegaDevega · Joined: 14 Mar 2006 Posts: 2 Location: Banffshire, UK

About the "red screen of death",

Have you been playing around with the ROM, ie hacking or changing it?

Alot of Megadrive games contain routines where every 16-bits of the ROM (after the header) is added together and compared to a "checksum" that is also calculated (and inserted) in the same way when the game was made.

If the two numbers don't add up (which means someone's been naughty) then the game will display a red screen and explode in your face and kill you. Razz

Alot of ROM images are "dirty", which means the checksum will be calculated wrong. There are some good tools on the 'net that will fix them for you.

jmrydholm · Joined: 05 Apr 2005 Posts: 12 Location: Michigan

Here's a new message I get recently:
When running DreamWriter (Genesis) 2.1 after a few minutes or so, I get a small window that pops up every few seconds that reads "MDMTLK: Priveleged instruction." Never had this problem until now. Is there something that could be interfering with the way the cart is read or something?