Discussion in 'Sega Dreamcast Development and Research' started by Laurent, Nov 21, 2017.
I found some interesting disc
I presume its To repear build . I don t really know
It looks like a diagnostic disc used for official repairs.
Its look like the same of the dreamcast C1/C2 checker ( console) ...
I have 2 GD driver repear program v 0.1 and 2 dc checker for repear ( silver ) To trade....
Its maybe To check a master before his duplication...
what kind of trade are you thinking?
I have purchased 1 of each, so stock is running out.
I will do a dump and MIL-CD conversion for both when I receive, even though I know at least the DC checker has been released before.
I had the loop checker GDI at one point and I may have made a mil-cd, but it's lost now so I'm very interested.
Looked through my files and I do still have the dump of the DC checker, along with the MIL-CD that atreyu187 made.
Regardless, I'll do another dump (if it's the same as the existing dump we'll get a match for TOSEC, if it's different then perhaps we'll discover a new software version). And I've never seen this GD Drive Repair program before, so it'll be interesting to play with it and dump it.
This appears to be correct.
Software on the disc shows "Ver0.2" in the upper right corner when running the test (see screenshots above).
The C1/C2 Checker console has the system wired up with a custom BIOS and a serial port. The custom BIOS boots directly to this checker program. The checker program on the console in the example is "Ver0.3" however.
Here are pictures and a screenshot from Wombat.
From what I can gather, this disc was intended to test GD drives during the repair process.
The C1/C2 checker was intended to test discs during the manufacturing process.
Both of them use the same software code to test in these different use cases?
So a custom bios for C1/C2 checker, was it dumped?
its whats i understand:
You burn the build from your dev kit on a GD-R . Thats your Master
You use this disk to be sure his correct , his conform
You send after your master to the editor or publisher.
The publisher use the GD-R on a duplicator kit to....
process of complète week checking is maybe 8 - 12 hours. I stopped after 4 hours.
random seek checking of a beta doesn t boot
Never been dumped AFAIK. Here is more info about it:
it seems was like that in early times, later it was changed to submit product as both GD-Rs and master disk(s) image(s) in CDCraft CIM format on tape drive.
from SDK SOEGDMastering.ppt:
Cool, interesting that it boots directly to it without the swirl. I wonder how SEGA bypassed all the security checks.
It's a special hardware revision.
all ? there is only 2 parts of security: 1) bios rom checksum protection (calculated by HOLLY chipset); 2) 2x GD-ROM commands, which supposedly check disk security ring wobbling.
1st part is not a problem, since Sega knows sum algorithm (but we still don't ).
2nd part - I'd guess they simply omit that 0x70/0x71 sec check commands, same as do Dev.Box bios roms.
SEGA probably changed the HOLLY chipset to disable the first check, like FG said. Interesting nonetheless.
Also, they have the blueprints/sourcecode to everything. They can sign their own bios however they like.
manufacture special chipset version for some C1/C2 checker unit ? it doesn't look sane.
also I don't think Sega itself designed or manufactured any of chips used in Dreamcast, as for HOLLY chipset, ie heart of Dreamcast - it is mostly Videologic made (possible DMA, G1/G2/Maple buses, etc parts was by NEC, but I doubt in this), so its more like UK developed, not Japanese at all :rofl:
right, I'd bet is was like that.
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