yea, the other logo seems to be the mini logo.

I think the loader.ini may actually have the CRC checksum, as I found this in dec location 1508209.

To set %s to %s with file checking on %s path, type bootmon -ax %s

After reading this we might be able to just turn the checksum OFF

Man, this is better than watching "24"

Keep up the great work guys!!!

I think y'all should put the dilithium crystals in the pseudoscillogism and excommunicate the redundancies in the biosphere as supercalifragilisticexpealadociously as y'all can.

Keep up the good work, everybody. I can barely type, so I'll just stay off to the side here and cheer.

JV

:iagree:

Okay, so I modified the original V26.09a navboot file so that it has the OEM splash logo. I made sure that the original file and the new file were identical. Next, using my hex editor I did a "CRC16/32 of file/block" calculation on the original and modified files and surprisingly they return identical values.

Next step is to slow burn the image using DVD Decrypter (preference thing, I hate Alcohol120%) I'll save that for tomorrow, kinda tired :yawn:

Keep my fingers crossed. Not quite there yet folks, you gotta hand it to the X5World braintrust :bow:

Good plan...

Tried the following with no luck (same error)
- changed 2 bytes (2 characters) in the middle of the GIF logo file embedded in NAVBOOT - ie. same filesize
- ensured that the NAVBOOT datestamp was exactly the same (to the second)

The good news is that when it fails, all you have to do is put the 'official' CD of v26.09A into the Navigation Computer and it installs & functions properly. This saves having to go back to v26 and then do the 'update'.

If we do find out how to get it to work I would think that we could have virtually any splash screen we like. Clearly file size is not the issue as this 'T 26.09A' image is much smaller than the '==BMW==' image (and the colour table is different too).

Paul Martin
Australia
www.paulnika.com

this suspense is INTENSE!

Hope this helps........

I have been analyzing the files.

All the data files (programmes), appear to be derived from C or C++. So I dont think we can simply recode to avoid the checksum...that would be bad!

Anyhow ALL the files end 00xx xx xx. ie the last 3 bytes of the file apper to be the check sum.

This represent not a 16 bit or 32 bit checksum but a 24 bit checksum!

Having a wander around the web I did find a reference to the fact that OS-9 does use 24 bit CRC checking.

Therefore to me me it looks like the navboot files checksum is the last 3 bytes of the file itself.....

now all I have to do is to find a 24bit CRC calculator!

Good huntin'

Altered 'navboot' with corrected CRC-24 uploaded to:
http://rapidshare.de/files/13622411/navboot.rar.html

Need to test it.

Is anyone knows a type of processor, used in MK4? I think, it's some kind of MIPS processor. I found a page with a variety of MIPS emulators and debuggers here http://www.linux-mips.org/wiki/Emulators Maybe it can help us?