[Coco] MC-10 vs CoCo2 questions.

Robert Gault robert.gault at att.net
Thu Jun 16 15:08:34 EDT 2016

John Lochey via Coco wrote:
> Hi all,
> I'm super new, so sorry for the basic questions.
> The MC-10 has a 6803 processor and the CoCo2 has the 6809 processor as I understand it.  I own both machines and would like to learn a lot more about them.
> I have been through the "Extended Basic manual" and the manual for the MC-10, but now I would like to try some entry level ML coding.
> I'd like to start playing with ML on my MC-10 as well as my CoCo2, but is this really smart, or should I really choose one to learn on because they will be so different due to their processor variance?
> I'd like do my ML learning via emulation and utilizing ML programming tools that run right in the emulator like EDTASM+ or SDC80C.
> Where/how can one start to learn the "memory map" of these machines?  Again, the difference between the two may force me to either learn both simultaneously or choose one.  I have a PDF of the book "Color Computer Memory Map" by Bob Russell, is that a good place to start or ???
> I appreciate all help!
> Thanks!
> John

One thing to keep in mind is that while many of the opcodes and the resulting 
8-bit values are the same for both processors, there are opcodes for the 6803 
that do not exist for the 6809. That means you can't use EDTASM+ to generate all 
6803 code unless you "hand code" the special 6803 opcodes.

I'd suggest that you start with your CoCo2 and EDTASM+. When you are comfortable 
programming on the CoCo2 for the 6809, then you can define the extra 6803 
opcodes with ex. statements such as:
aba	EQU	$1B
cba	EQU	$11

Then you can use these with EDTASM+ in code as follows:

	FCB	aba		* when you want to use the opcode aba


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