On Mon, Feb 8, 2010 at 4:31 PM, N0body H0me <n0body.h0me at inbox.com> wrote:
From what little I've managed to gather, the 6829
had some limitations that made it either difficult to use, or otherwise impractical for
many (if not most) applications. ?I've read someplace, for instance, that you were
restricted to four tasks. ?I suspect for that reason,
they're rarely seen. ?They were rare even in their own time.
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.
-ethan