Mk6 boot up issue

[Don Indallas]

Here is the information on my screen during boot-up.  What do you think causes this error on boot-up?



Video init OK.
System EPROM checksum ok.
System EPROM CRC ok.
DRAM ok.
CPU ok.
SRAM ok.
USA platform found.
Market AVL media present.
Market AVL media header checksum ok.
Market AVL media checksum ok.
Market AVL media CRC ok.
Game EPROM present.
Game EPROM header checksum ok.
Game EPROM checksum ok. Game EPROM CRC ok.
AVL media present.
AVL media header checksum
AVL media checksum error!
Restarting in 10 seconds,
ok.


Microscopic/unreadable size font fixed. Please CHECK before posting and change font size if it's too small. OR... just post and don't change anything with font.
~moderator

[The laneman]

If the game eproms are copies its usually means that they werent completely erased before programming.
Even though it shows its erased during a eprom blank check there was something still there,even if its just 1 byte of info.
When I get that error I double the erase time of the eproms and program again.That usually solves that error you are getting.

[Don Indallas]

Thanks for the information. I will make sure that the erase is complete, and try it again sometime.  Thanks!

[The laneman]

You're welcome.Let me know if that works.

[Don Indallas]

I will let you know.


Thanks again.

[Kenokarz]

sometimes that happens if you used the wrong systems chips for that game ,some games wont run on some of those  system chips , reach out to laneman he had a chart that showed what system chips went with what games

[Don Indallas]

I erased the eproms for extra time.  Some of the ones I have erase easily, some take a long time.  I gave these lots of time, and Laneman, you were 100% on the money.  Thanks!

[The laneman]

Glad that worked for you.That problem drove me nuts the first time I had it trying to figure out.
The game program must look for a exact checksum for each eprom.

[Heihachi_73]

MK6s don't check each individual EPROM, everything is loaded as one contiguous set of data which is interleaved between the left/right chips - there are two separate checksums, one for the program code and another for the AVL (which presumably means audio/video library, as it contains the game's resources). As shown by the text in the original post, the system base also checks itself in the same manner before checking the game data, as do the setchips.

It's an evolution of the MK5 software, except that MK5s have separate graphics and sound sections instead of an AVL. One good thing about MK6s is that they at least tell you in the POST if anything's wrong with the chips - MK5s with bad data beyond the program code area (for example a bad U13 chip) don't tell you anything, they just reset over and over while "passing" the startup tests, the only time they fail the POST is if the program code is corrupted or there is a board fault (e.g. DRAM error). MK5s perform a code checksum in the POST, and then after it says System Startup Code Entered, it silently checks the same program code (again) as well as checking the graphics and sound data sections, and then attempts to boot once all three checks have passed.

[Don Indallas]

Heihachi_73,


Thanks for the great information.  I love knowing more about how these devices work.  I appreciate your input on this.  Thanks,


Don

[Heihachi_73]

Documenting these things is the only way to preserve them and to aid in emulation for when the original boards are slowly dying out, although that's for another forum topic. With over 500 MK6 games (including clones) released in the US alone it's going to be one long winding road.