Hi Col,
I'd suggest digging out the 68k pod manual and looking at the back of
the pod. There are details on the address prefix you use to control
whether you're doing a byte or word read, and also user or supervisor
mode.
I think you can ignore supervisor mode for the time being and run some
tests using the byte and word address prefixes in user mode. Basically
you add a byte value to the start of the address range and these codes
determine the addressing mode of the CPU.
The 68k will trap if you try to address a non-word boundary, so the
fluke or pod is doing a bit of magic to get single byte reads back.
I suspect your checksums are a bit dodgy either because you're reading
every other byte, or that you're checksumming words when the tool
expects byte input.
I promise things will become much clearer when you've correlated the
back of the pod instructions with the manual section on addressing
modes :) It's not just a normal pod.
Good luck,
Tim
Sent from my iPhone
On 9 Jun 2010, at 21:29, "Colin Davies"
<colin.w.davies@btopenworld.com> wrote:
> OK... That kind of makes sense.....When I get my pod pluged into the
> working board again (once I've fixed the header) , I'll try to do
> some homework !!!
>
> eg.... read location 0000 in.... and see if its 16 bits and the pair
> of 8 bits matches the first bytes of both roms :-)
>
> This A0 missing has confused me somewhat, lol !!!
>
> Cheers, Colin
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Received on Wed Jun 9 17:44:10 2010
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