On Mon, 26 Aug 2002, Bill Studenmund wrote:

> On Mon, 26 Aug 2002, Matt Fredette wrote:
>
> > I guess I could try to finish it up, but one thing that always discouraged
> > me about 68000 PIC is the limited process address space: only 16MB total.
>
> ???
>
> Is that due to the ABI or what?
>
> [I think this is Motorola ASM syntax]
>
> 	MOVE	#$12345678, d0
> 	LEA	(0, PC, D0), a0
>
> will give you a 32-bit offset relative to the PC, won't it?

  Not really, it will give you a 24-bit offset relative to the PC with
"garbage" bits in the upper 8 bits that will be ignored.  [Or useful to
Microsoft to keep a byte value in pointers stored in memory and breaking
the program when upgrading to a a CPU with real 32 bit addressing :-)]
The 68000/68010 only has a 24 bit address bus.

--
Michael L. Hitch			mhitch@montana.edu
Computer Consultant
Information Technology Center
Montana State University	Bozeman, MT	USA