Path: utzoo!attcan!uunet!husc6!bloom-beacon!mit-eddie!ll-xn!ames!ncar!noao!nud!mcdchg!michael
From: michael@mcdchg.UUCP (Michael Bodine)
Newsgroups: comp.sys.m68k
Subject: Re: opcode emulation (Was: Re: 68020 in a *68010* socket?)
Message-ID: <10440@mcdchg.UUCP>
Date: 20 Jun 88 15:30:16 GMT
References: <17206@gatech.edu> <10123@mcdchg.UUCP> <17479@glacier.STANFORD.EDU> <6276@cup.portal.com> <17482@glacier.STANFORD.EDU> <182@elgar.UUCP> <3447@pdn.UUCP> <1267@percival.UUCP>
Reply-To: michael@mcdchg.UUCP (Michael Bodine)
Organization: Motorola Microcomputer, Schaumburg, IL
Lines: 30

Michael Galassi (nerd@percival.UUCP) writes:
> This info is gleamed from "mc68010/mc68012 16-/32-bit virtual memory
> microprocessors" printed by Motorola in May, '85, this document is
> labeled as "Advance Information" so may be inacurate or incomplete.
Motorola only changes the "Advance Information" part of a data sheet
when it gets reprinted *AND* there are functional changes to the 
document.  Your info re: 012 is accurate.

> Personaly I have never seen the 012 and do not recal even reading
> of any products using it.  Maybe the 012 never made it out of sample
> phase?  
The 012 was essentially a special product for a particularly large
company who was interested in a) making the 68000 family fit into the
I/O type instructions of intel, thus the A0-A29 + A31 pin-out -- the
A31 was used to distinguish memory accesses from i/o accesses and b)
putting the 68000 into a virtual, multi-processor environment, thus
the 68010 to give the virtual part, and the RMC pin to inform the
complementary part of the forthcoming indivisible cycle.  

The 012 is indeed being used for its intended purpose but in very small
quantities.  No doubt due to these tiny quantities, it's no longer
listed in the Motorola Semiconductor price book;  I would suspect that
today's 12 MHZ 68020 is about on a par cost with what the 68012 would
cost.  Unless you're already locked into using the 012, the 020 is the
right part to use.
-- 
[ Michael Bodine, michael@mcdchg.UUCP Opinions expressed are mine and haven't  ]
[ been seen, commented on or in any way approved or even allowed by Motorola   ]
[ MicroComputer Division, Motorola General Systems Group or Motorola, Inc.     ]
[ No one else agrees with me;  why should my employer?			       ]