[Coco] How to get into CoCo 6809 assembly?

[Robert Gault]

Blake Patterson wrote:
> So I've now got both a DriveWire and a FD-500 floppy disk system (though one of the drives is apparently not connected inside the enclosure - need to figure that out). I'd like to fiddle around with 6809 assembly on the CoCo 3.
>
> Can someone point me to an assembler package I'd need? I'd like to fiddle around with CoCo 3 screenmodes, etc -- so I want to write a few "CoCo 3" vs. prior programs.
>
> Also, what's a good general 6809 reference and reference for the internals info I'd need to access the CoCo 3 itself?
>
> Thanks much, in advance!
>

You should try Tandy's Disk EDTASM+ which should be in the following zip file:
http://www.tandycoco.com/dsk_imgs/rs-dos/cocodownunderrsdos.zip
It may be at other sites also.

If it turns out that you want a better enhanced version, you can consider the 
patch I sell for EDTASM+.
http://aaronwolfe.com/robert.gault/Coco/Sales/Edtasm6309.htm

If you decide that you would rather work with a full screen rather than a line 
editor, consider buying one of Roger Taylor's products such as RainbowIDE. You 
can create source code, assemble it, and immediately test it in MESS Coco emulation.

One of the best books on the 6809 is "6809 Assembly Language Programming" by 
Lance A. Leventhal. You should get a copy of the Coco3 service manual:
ftp://maltedmedia.com/coco/MANUALS/TANDY/HARDWARE/COCO3/
You should also get a copy of all the Spectral Associates "Unravelled" series:
ftp://www.rtsi.com/RSDOS/incoming/UnravelledSeries/
Many good pdf files, including the Leventhal, are at 
http://cococoding.aaronwolfe.com/home/docs