JUGSDD nothing more than Development Jagcd bios rom?!?

[Gunstar]

Has anyone (besides me) tried to use BSG on a Jaguar development system? I decided to plug it in and give it a go since my Jag dev. system is hooked up to an RGB monitor, wanted to check it out in RGB! So, I plug it in and hold down "B" and the usual Jaguar start up screen comes on, right, nothing unusual so far...Then guess what comes up? The Jaguarcd startup screen! (I don't have a jagcd hooked up to the dev. system, all I have is a production cd player and they won't work on dev. systems, you need a dev. cd player!) But, instead of BSG loading up, I get the picture of a Jagcd with the arrow pointing to the power supply socket of my non-existant jagcd! Curious says I, so I decide to plug in my jagcd just for kicks and curiousity, and of course it doesn't work because it has to go through the production Jagcd's bios which doesn't work with my dev. Jaguar. But, this leads me to very strongly believe that the great JUGSDD bypass system is merely a copy of the development Jaguarcd bios rom

 

so, anyway, BSG won't work on a Jaguar dev. system without a dev. cd unit too, at least not on the early dev. system model I have, with the blue screen...just like Songbird carts that have the hardware bypass in them!

[LinkoVitch]

that does sound like a modified version of the Jaguar CD BIOS is whats being used. I would have thought that very naughty indeed.

[TXG/MNX]

that does sound like a modified version of the Jaguar CD BIOS is whats being used.  I would have thought that very naughty indeed.

 

Hmm sounds like a smart and dirty trick ...

[Gunstar]

It's definately ingenius, I'll give them that, but it makes me question the right to call it JUGSDD and copyright it. I'm positive at this point that it is a dev. Jagcd bios, even if it has been modified a bit, but it maynot be modified at all. When I use it on a normal Jag/Jagcd, the standard Jagcd startup screen comes up then the game comes up like normal, but if you hold down "C" as you're supposed to, to run JUGSDD, the screen goes black for a second and then the Jagcd start-up screen appears again and everything starts working like normal (or at least normal on a dev. cd unit). Something about the Jaguar dev. base unit seems to be triggering the dev. cd bios to start without holding "C" down, maybe something to do with having to hold "B" down on the dev. system to bypass the development startup screen is causing the dev. cd bios in BSG to initiate instead of the game, but since the bios checks to make sure there is power to the cd unit, it shows the picture of the cd unit with arrow pointing to the power port because it's not finding the power it expects, since no cd unit is plugged in, just like any Jagcd unit would do if it weren't plugged in. With all the systems, dev. or production, that Scatologic has on hand, I would have thought they would have at least tested the BSG cart out once in a dev. unit and discovered this...maybe they did and decided it didn't matter.

[TXG/MNX]

Hmm I don't care how they did it, it just works good just like Protector SE...

[Gunstar]

Hmm I don't care how they did it, it just works good just like Protector SE...

 

Nor do I care how it's done, you've got that right. But they can't copyright something that isn't theirs to begin with, though I don't think they are doing anything wrong in using it, I think it may fall into the public domain catagory when the Jaguar was released into the PD or whatever, i'm not sure how extensive all of that is, but a rose by any other name is still a rose...

[atarifan49]

Yes, BSG CD boot method is based on the Jaguar CD boot code that Atari provided developers. So is the B&C Bypass cart. Protector SE is based on a routine that Carl developed on his own. I helped him with compatiability testing of his routine.

 

But with BSG I'm not sure exactly how T-bird implemented the CD boot code comapred to what I did with the B&C cart.

 

The reason the developer stub ROM and production CD unit don't work well together is becuase when you hold 'B' to start the cartridge, control is handed over to the CD boot ROM. Which then attempts to look for and authenticate a CD. To get around this you need to put the developer ROM in your CD unit also. Doing something similar to the BJL mod, but with a 27C040 size EPROM, and put both a regular CD boot ROM and a developer boot ROM gives you a nice setup.

 

Regards,

Glenn

[Gunstar]

Yes, BSG CD boot method is based on the Jaguar CD boot code that Atari provided developers.  So is the B&C Bypass cart.  Protector SE is based on a routine that Carl developed on his own.  I helped him with compatiability testing of his routine.

 

But with BSG I'm not sure exactly how T-bird implemented the CD boot code comapred to what I did with the B&C cart.

 

The reason the developer stub ROM and production CD unit don't work well together is becuase when you hold 'B' to start the cartridge, control is handed over to the CD boot ROM.  Which then attempts to look for and authenticate a CD.  To get around this you need to put the developer ROM in your CD unit also.  Doing something similar to the BJL mod, but with a 27C040 size EPROM, and put both a regular CD boot ROM and a developer boot ROM gives you a nice setup.

 

Regards,

Glenn

 

I don't suppose you offer a service to burn this 27c040 eprom do you? like your "fix the flashrom" service? Maybe a link to the mod instructions if any exist? i would like to mod my cd unit to have both boot roms.

[Stone]

Maybe a link to the mod instructions if any exist? i would like to mod my cd unit to have both boot roms.

 

And as if by magic, a link appeared...

 

Main site root is here, thanks Robert!

 

Stone

[Gunstar]

Well, from the looks of that mod, I think I'm going to have to replace my '93 stubulator rom with a '94 one...why is that anyway? Is it because the '93 stubulator doesn't support the dev. Jagcd since it was still basically on the drawing board at that time? Or does it really matter and I can do the mod with my '93 stubulator rom regardless of what the mod instructions say? Also, I'm obviously going to have to hire someone to program the chips for me and burn the eproms/flash rom, but I can do the mod on my own otherwise. I figure I might as well go the whole nine yards, including the 512k flash rom, and just keep the '93 stubulator and get the '94 stubulator, BJL and production BIOS roms all on the flash rom chip using that extra rotary switch as described in the mod (for the base unit). Then get the jagcd modified with the dev. bios and keep the production bios too with a switch for it.

[+rdemming]

Well, from the looks of that mod, I think I'm going to have to replace my '93 stubulator rom with a '94 one...why is that anyway? Is it because the '93 stubulator doesn't support the dev. Jagcd since it was still basically on the drawing board at that time? Or does it really matter and I can do the mod with my '93 stubulator rom regardless of what the mod instructions say?

 

The Stubulator '94 is indeed needed with a CD-rom drive. The 93 version doesn't recognize the CD-ROM bios wether it is the normal or the developer bios.

The 94 version works with the CD developer bios or the retail cd bios.

With the stubulator 94 you can hold B while turning on the system to start a (unencrypted) cart directly. Hold C while booting to start the CD-bios.

 

BattleSphere does indeed behave strange with the stubulator bios. Holding B does directly start JugsDD and boots an unencrypted CD instead of starting BSG.

Maybe this behaviour is by design because in this way it is faster to boot unencrypted CDs than on a retail Jaguar. The Stubulator '94 / BSG combination starts the JugsDD directly while a retail bios / BSG combination first starts the regular cd-bios which in his turn starts BSG/JugsDD.

 

Robert