N64 Gameshark Breakpoints/Test Mode by HyperHacker at 10:44 PM EST on November 23, 2008
hcs, when you reversed the Gameshark protocol, did you by any chance look into how breakpoints are done in GSCC? I'm wondering if there's a special command or a RAM address to write to, or if it directly accesses the MPU registers or injects a routine to do so.
by HyperHacker at 10:45 PM EST on November 23, 2008
Also, did you look at the code of the Gameshark itself? There are strings in it that suggest some sort of test or ROM flash mode. You mentioned it won't boot up with some pins high; maybe it's looking for a specific value to enter this mode?
I didn't look at breakpoints. I can't see how it could be done without using watchhi/watchlo. I looked at the code but came to no conclusions. When certain pins are high the LED will light up when you plug in the parallel port, I suspect this is more of a glitch than part of a flashing thing. There is a ROM flash mode, but I have never looked into it, too concerned with bricking it. Though now I have a spare GS, so maybe some day. Ice Mario had discussed flashing stuff back when I was working on it, but nothing ever came of that.
By the way, from the time of posting you have a whole day to edit a post.