Hi,
I've recently dug out my old Jaguar devkit from the loft (NTSC console with Stubulator ROM, & 2MB Alpine board), and have been trying to test if it all still works. I was originally shipped this kit back in the mid 90s in order to do some audio code work for a client, all fully Atari-licensed, who never asked for it back and it's been in the loft ever since!
After a lot of digging, I managed to verify that the Alpine board seems to work fine - I was able to use the available Linux tools, mainly rdbjag, to perform several operations with the kit, send over a bunch of ROM images, etc. The Falcon which came with the kit found another home many years ago, to make a bit of room in the loft - wish I'd hung on to that now though.
What I'm curious about though, is running a regular retail cart on the Stubulator-modified console. I tried a couple of carts owned by a friend, and they both seem to work (if I power up the Jag whilst holding the B button on the controller, otherwise it boots to a blue screen with a development system message) but the audio output is highly distorted. Running the same games by uploading their images to the Alpine board, the audio is fine.
I really don't know very much about this system, so was wondering if anyone here might know what could cause this? I don't think the audio output is broken on the console, otherwise running the games via the Alpine would surely have the same problem. The only thing I could think of was that perhaps there's something electrical which isn't right when the Alpine isn't present (perhaps grounding or something?), since there's a small ribbon cable coming out of the console's case which plugs into the Alpine, and this remains unconnected of course when using a retail cart.
Also, I'm not sure if this is normal on these developer Jaguars but the main red power switch appears to be totally unconnected on mine - the console simply powers up when connected to the mains, and the switch does nothing. But this is how it came to me from Atari, via the client
Many thanks in advance for any replies!