MultiBIOS question

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Ketsuban
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MultiBIOS question

Post by Ketsuban » Sat Feb 20, 2010 8:25 pm

I'm collecting hardware for the Megadrive for development work, and I'm trying to make sure that I'm well-prepared to deal with pesky region lockout and other such things which have no business existing on a console which hasn't seen an active commercial development in fifteen years.

My MD1 arrived premodded with 50/60 and region switches, and a now-redundant SCART cable hanging out of the corner; thank you to whomever I bought it from for that. :P I will be adding a PAL/NTSC switch to my 32X, and have the instructions for that bookmarked. The last piece of the puzzle is the MegaCD1 which I will hopefully be getting in the near future.

I intend to replace its BIOS with a MultiBIOS, following Arakon's instructions. I dislike the graphical modifications he has made to his MultiBIOS, but thankfully mmmonkey helpfully provides his own made from the standard BIOSes. What concerns me is the warning that the Japanese BIOS causes the system to lock up. Can this be fixed? (I don't intend to make mine switchless - I dislike switchless region mods.)

Chilly Willy
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Post by Chilly Willy » Sat Feb 20, 2010 9:00 pm

Read the warning closely - it freezes when you switch it WHILE THE POWER IS ON. That's because the code is in different places, and switching causes the cpu to start executing in the middle of nowhere. As he says on the page, just turn the power off and back on and it will run.
Switching to JPN mode freezes the console up, I have to power off and back on to use JPN mode
See? It works, but you need to cycle the power to make it boot from the very start. I imagine that it doesn't reset because the layout of variables in the RAM is different, and resetting doesn't clear the ram.

Ketsuban
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Post by Ketsuban » Sat Feb 20, 2010 10:02 pm

Ahh, okay, thanks for pointing that out - I'd managed to miss that. That's a relief, then - it won't affect me since I won't be changing region while the system is running.

TmEE co.(TM)
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Post by TmEE co.(TM) » Mon Mar 08, 2010 3:55 am

You can alternatively install "Hard Reset" switch, that will have same effect as power cycle, except its not "destructive" on the hardware.
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