Subject: MC68010 vs. MC68000 (Was: "Re: Is gcc slow? Or is our gcc slow?")
To: None <>
From: Greg Earle <earle@isolar.Tujunga.CA.US>
List: current-users
Date: 04/11/1996 11:55:07
> Hello All,
>   I'm not sure why you would want to re-run a failed bus cycle, but:
> The above is from a Motorola publication title "MC68000
> 16-/32-bit Microprocessor" and dated October, 1985.  It is
> labeled as advance info.  Section of the "M68000
> 8-/16-/32-Bit Microprocessor User's Manual", 8th ed, copyrighted
> 1990 has essentially the same info.

The relevant stuff as to why you need an MC68010 (in addition to an MMU) is
in section 1.4, "Virtual Memory/Machine Concepts".  The most important point
was the instruction continuation feature instead of instruction restart.
That's mentioned in 1.4.1.

I loved that "M68000 16/32-Bit Microprocessor Programmer's Reference Manual".
Probably the easiest book on "How this microprocessor works" I've ever seen.
(A lot easier, for me, than "The SPARC Architecture Manual  Version 8", e.g.)
Even I could understand it  :-)

(Unless you want to take this off to "port-m68k" or something, I suggest we
 keep this off of "current-users" ... )

	- Greg