Re: A89: Re: Re: Re: Re: CORRECTION: Shift+ON
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Re: A89: Re: Re: Re: Re: CORRECTION: Shift+ON
No, i't because 68000 has a 24 bit wide addressbuss,
even though the PC is 32 bit. All 68000 has 24 bit wide busses, so it is a
characteristic of the CPU itself. (actually it is 23 bit and one odd/even bit,
but that's really the same thing)
The custom chip in the 89 has only 21 bit wide bus. Thats because of the
decodeing hardware, (or rather, because it would be silly of them to put pins
that would never be used on the custom chip.) but as you see, it doesn't matter.
//Olle
Patrick Davidson wrote:
>
> On Fri, 18 Aug 2000, Scott Noveck wrote:
>
> > Yes, HW2 calcs contain a hardware block, while on HW1 calcs, it's merely
> > software. As you said, it requires that the PC be within a certain range,
> > but TI didn't realize that on our beloved 68000, (PC) and (PC+256k) are
> > actually the same address. Replace the former with the latter and it runs.
>
> This is actually the result of the calculator's address decoding hardware,
> not a characteristic of the CPU itself.
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