[Coco] An MC68HC11A1P Based Computer Idea

john dumas JohnDumas at austin.rr.com
Fri Jul 20 11:52:40 EDT 2012

On 7/20/2012 7:38 AM, jdaggett at gate.net wrote:
> John
> 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
Do you have a copy of that datasheet?
The datasheet search engines on the web find no 6811.....
> 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.
Actually, the 14 prefix was for CMOS and the HC infix was for HCMOS - 
different processes.
> That may very well have been an oversight of the marketing department and had little to do
> with engineering.
> james
Google is your friend and the term "6811" comes up with TONS of hits for 
6811 & 6812.
But after following dozens of them, I found that they fit in 3 catagories:
1) Nothing to do with micros
2) No useful info - no datasheet, description, etc
3) Improper nomenclature for the HC11 and HC12.
Like this:

As far as a datasheet from MOT saying 6811, I sure never saw one and
neither google nor the datasheet engines were able to come up with one
when I searched. Of course, knowing the way that, at least, one or two
"marketers" functioned, I can believe almost ANYTHING from them!!!

During that time, Jim (Mr. HC11) was part of our daily  lunch group and
I think that he would have mentioned an NMOS version if one existed.
At least once, anyway........and Jim was not shy(rightly so) when
talking about His Baby!

I truly believe that folks who use the 6811 moniker are just making
a shortcut for the HC11. And we *KNOW* there never was any
possibility of an NMOS 6812 - NMOS was ancient history (for new
designs) by the time the '12 was designed............


More information about the Coco mailing list