Re: A92: C -- a limit on ROM calls?
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Re: A92: C -- a limit on ROM calls?
>ANYWHERE in my program then l can get the title screen to display, but
>pressing a key after that causes a Line 1111 Emulator error.
I'm just going to throw in the only relevant two cents I have. Line 1111
errors occur when you address an opcode out of the 68000's instruction
set--with the high-order bits set to 1111. This error originates in the
assembler usually, but can also happen if you jump or branch to non-program
data, particularly negative numbers (which will have one or more high-order
bits set). You can also get a Line 1010 error for similar reasons.
(Somebody correct me at this point if I've fallen off the turnip truck.)
Now, keep in mind that I have little programming experience--I just design
the microprocessors. :-) Since A68K probably isn't spitting out invalid
instructions, we can rule it out. Here's what I'm thinking.
--One of the subroutines you're jumping to may have corrupted the
stack. Subroutines push the calling address onto the stack, and use it to
return. If the last value on the stack when the subroutine exits is an
address to a word that starts with 1111, you're screwed--Line 1111
Emulation Error.
--For some reason, you're jumping to a non-instruction word right after the
key press.
That's about all I can come up with. I'm sure some gurus on this list have
seen this before. :-)
--Cliff Biffle
Optimist: This glass is half full.
Pessimist: This glass is half empty.
Cynic: They drank my water. Figures.
Engineer: The glass should be -half- this size!
Psychoanalyst: The glass is affected by feelings of inadequacy.
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