[A89] Re: change the SR
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[A89] Re: change the SR
> > by the way you do not need to use the low memory protection port just add
> > #$40000 so to the pointers so that you get the wrap arround effect.
>
> i dont really understand this sentence
The hardware in the 68k TI calcs have a built-in protection mechanism
for memory below a certain address to prevent runaway programs from
writing in sensitive memory areas like the interrupt tables, handle
tables etc. To deactivate this you clear bit 2 of 0x600001(byte).
The alternative, as Samuel points out, you can also add #$40000 to
the address you're writing to since the calcs only use a certain
number of the address bits anyway and will wrap around with a modulus
of $40000, but the protection looks at all the bits and therefore
thinks your address is valid.
--
/ Niklas Brunlid
Check out Prosit for the TI-89 / TI-92+ at http://prosit.ticalc.org
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answer is: Hey, whatever I select.
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