[Coco] 2-meg mem capable 6809 before the gime and coco3?

[Fedor Steeman]

Cool!!! I am still hooked on the CoCo4 proposal by SockMaster (
http://www.axess.com/twilight/sock/cocofile/coco4.html) where this neat
little chip may fit right in with the three 6309 CPUs!

Cheers,
Fedor


2009/8/22 Wayne Campbell <asa.rand at yahoo.com>

> I found a copy of the MC6809 programming manual (from Motorola) on the
> Freescale Semiconductor site. I started reading through it. Boy, did it make
> me sit up when I read this:
>
> MC6809-MC6809E Microprocessor Programming Manusl
> Original Issue: March 1, 1981
> Reprinted:      May, 1983
> Section 1 - General Description
> 1.2 Features
> Page 1-2
>
> A Memory Management Unit (MMU), the MC6829, allows a M6809 based system to
> address a 2 megabyte memory space. NOTE: An arbitrary number of tasks may be
> supported -- slower -- with software.
>
> This means the original CoCo could have been made in a way that would have
> blown away everything else around, with the exception of the 16-bit
> processors that were around by then. But DOS would have been kludging along
> with 640K while the CoCo would have been flying along at light-speed!
>
> If you ask me, a CoCo4 would be parallel processing with 2 6809 processors
> and 4 6829 MMUs (that would be 8 megs of RAM per processor?), but then, I
> don't know anything about what would be required to make that hardware work.
>
> Wayne
>
>
>
>
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