[Coco] [Color Computer] 6809/68000 Was: [CoCo] Atari and Amiga comparison

[James Diffendaffer]

Yup, they were from about the same time so development was going in
parallel. 

I just wish the 6809 had been just a little different.

B should have been the MSB of D.  For the 6309 it should have
continued in the MSB direction with the new registers.  It would be
better for compilers.  It simplifies type conversions between
different byte sizes.

I wish it had caught on in more embedded systems.
Just look at the Z80.  Now there are the Z180, eZ80 and Rabbit chips
with some having clocks up to 50Mhz.
Imagine a 50Mhz 6309!  Yikes! 
Add a little cache memory and those longer 6309 instructions suddenly
don't take any additional cycles with the proper design.

Too bad some of Motorola's research hadn't come before the 68000
design started.  Some of the findings that went into later RISC chips
could have made it in the 68000 and it would probably still be in
desktop machines.


Quote------------------
I don't think they could have... weren't they designed around the same
time (1979)? The 68000 was the new breakthrough, super chip, and the 6809
was an expansion/extension of the successfull 6800 design.
Now, if Tandy (or late, Frank Hogg Labs with the TC-9) only had known
about Hitachi, we could have had a 3 MHz (minimum) 6309 based Coco 3. And
with the sales Tandy had, I am sure Hitachi could have brought out
official 4-5 MHz chips for sure, and possibly higher.

-- 
L. Curtis Boyle