[Coco] Learning assembly for the Color Computer

[Dave Philipsen]

I definitely agree with you on that, Robert.  I started out on the 
EDTASM+ program pak and it was definitely very handy for a beginner.  It 
was nice to set breakpoints and examine registers, etc.  Right now 
because I already have a Windows/DOS/Linux based cross assembler I 
wouldn't really go back to EDTASM but it was definitely the best for a 
starting point.

Dave


On 4/14/2016 3:56 PM, Robert Gault wrote:
> I'll add a book to Bill's list. It may or may not be on the Internet 
> for download.
>
> "6809 Assembly Language Programming" by Lance A. Leventhal, 
> Osborne/McGraw-Hill, 1981, ISBN 0-931988-35-7
>
> The platform on which you learn programming will make all the 
> difference in the world. It will most likely be either a real Coco or 
> an emulator, but the two real choices are for use under Basic or OS-9.
> When you program for Basic, you have essentially no ability to easily 
> interact with the hardware unless you carefully read the Unravelled 
> series to find useful access points in the ROMs. Of course other books 
> written for programming on the Coco will tell you about those access 
> points.
> When you program for OS-9 (NitrOS-9), it is easy to access all the 
> hardware as OS-9 include drivers that provide I/O to the screen, disk, 
> tape, printer, etc. The catch is that it is a much steeper learning 
> curve required to learn to use OS-9 in addition to learning assembly 
> language. :)
>
> In short, you will need to do more or less the same thing you did to 
> learn writing programs for Basic on the Coco. Write the simplest and 
> shortest program you can think of, probably copying one you got from a 
> magazine or book. Do that until it becomes second nature.
> Eventually you will remember the structure required for ml programming 
> and can easily lookup the op-codes needed. Continue and you will 
> remember the codes themselves. They are all based on the limited 
> number of registers contained in the 6809 and 6309 cpu.
>
> Personally, I think using Disk EDTASM to learn programming for use 
> with the Basic ROMs is the best route for a beginner. That's because 
> the package contains an editor/assembler for writing and compiling 
> code as well as Zbug. Zbug gives you direct access to memory where you 
> can read the ROM code and test your own code. Zbug permits 
> step-by-step progress through your code while watching what happens to 
> the registers and memory.
>
> Robert
>
>