[Coco] An MC68HC11A1P Based Computer Idea

jdaggett at gate.net jdaggett at gate.net
Fri Jul 20 08:38:36 EDT 2012


I am relying of memory here and stuffed away in a box in a deep dark closet i used to have 
several catalogs from teh early 1980's. I seemed to remember that originally there was 
marketed and labled a series of parts call MC6811 with no HC in the part number. It may 
have been CMOS. Lacking at the first the typical "HC" in the part number led to believe that it 
was based off of the standard used NMOS technology of the time. The very first CMOS 
production micro that I remember Motorola having available was the old MC146805E 
processor. That was around by 1981. It could only access 2K of memory due to the 12 bit 
address bus. 

You may very well be correct. Though the literature of the time listed a 6811 and not a 
68HC11. This at least suggests two different parts and possibly two different technologies. 
Back in the 80's I always saw Motorola usually prefixed the part number either with "14" or 
added HC after the "68" with alltheir CMOS computer chips and peripherals as I remember. 
That may very well have been an oversight of the marketing department and had little to do 
with engineering.


On 19 Jul 2012 at 15:11, john dumas wrote:

> On 7/18/2012 6:31 PM, jdaggett at gate.net wrote:
> > Actually it closer to the MC6803 than the MC6809. Before the HC version there was an
> > NMOS version called MC6811 that was based ont eh NMOS MC6803. Later the whole series
> > was moved over to high speed CMOS, thus the HC11 series.
> NMOS 6811????
> I was in the the design group throughout that period & I remember no 
> such chip.
> The 6801/03 was the forerunner of the HC11. Watched Jim Sib and crew 
> crystalize
> the design from 6801 AND (mostly)delco's requirements. Never saw an NMOS
> version or heard of anyone talking about an earlier NMOS 6811.
> [In the early days of production when MOT was shipping a 20 dollar bill with
> every hc11, I'm SURE that the management would have LOVED to have had an 11
> in the mature NMOS technology!!!]
> Do you have one to show?
> cheers,
> johnd
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