-----Original Message-----
From: emu at
e-bbes.com
Sent: Mon, 08 Feb 2010 14:59:28 -0700
To:
Subject: Re: 6809 SBC
Ethan Dicks wrote:
I'd never heard of it before today (I was
into the 6502 then as now).
Glancing at the datasheet, yes, there are registers to handle 4 tasks,
but you can apparently stack up to 8 6829s in one system for 32 tasks.
With 20 bits of memory addressing, it seems a reasonable balance (32
tasks in 1MB), but finding room on a board to stuff eight 40-pin DIPs
between the CPU and memory seems the harder job.
Just stack them ;-)
most signals are connected parallel ...
I'd like to see that! :^)
Seriously, though, I don't think Moto had general-purpose operating
system memory management in mind when they designed that part. The
feeling I get is that it was seriously slanted towards embedded
applications, where the size and number of tasks would be more fixed.
While it's true that OS/9 can be (and has been) embedded, I suspect
that the interest here would be to use it as a 'general purpose'
OS for different applications.
-Jeff
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