Re: [stella] Supercharger internals...

Subject: Re: [stella] Supercharger internals...
From: bwmott@xxxxxxxxxxxx
Date: Tue, 12 May 1998 21:33:35 -0400 (EDT)
> At 17:35 07.05.98 -0400, you wrote:
> 
> How would your emulation behave when a y-indexed write would
> cross a page boundary. One of my programs didn't do what I
> wanted it to do, but crashed completely on the real SC because
> of this. What happened was, that the write would not go to the
> desired address, but to an address 256 bytes below, because
> the CMP ADDRESS,Y hadn't fixed the page error yet. The old
> emulators just ignored the write.

In the current version of my Supercharger emulation an instruction
such as CMP ADDRESS,Y that crosses a page boundary would poke at
an address 256 bytes below.  Since the "real" address you're
trying to access would be the 6th memory location addressed and
the address 256 bytes below that would be the 5th memory location
addressed.

Brad
 
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Bradford W. Mott (bwmott@xxxxxxx)          Computer Science Department
http://www4.ncsu.edu/~bwmott/www           North Carolina State University
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