[Coco] 6309 port of NitrOS-9 Level 1

[Tormod Volden]

On Sat, Jan 24, 2015 at 11:39 PM, Tormod Volden wrote:
> On Sat, Jan 24, 2015 at 9:37 PM, Robert Gault wrote:
>>
>> No. There is no emulator of a coco1 or coco2 that incorporates 6309
>> emulation far as I know.
>
> I have been testing this in XRoar. The gdb disassembler doesn't
> interpret the 6309 opcodes but otherwise it works fine.

For everybody interested, this is how I test it in XRoar (after: make
PORTS=coco2_6309 dsk)

xroar -default-machine coco -nobas -extbas
$HOME/nitros9/level1/coco2_6309/bootroms/nos96809l1_1773.rom -load
$HOME/nitros9/level1/coco2_6309/nos96309l1coco2_6309_40d_1.dsk
-machine-cart rsdos -machine-cpu 6309 -gdb

I use the NitrOS-9 boot ROMs so I don't need the BASIC ROMs.

Exactly how the 6309 boot crashes seems to depend on non-initialized
memory, which could explain the non-reproducibility. When I start up
XRoar as above, it freezes on the sysgo welcome screen. If I do a hard
reset in XRoar (shift-ctrl-R) it will after the sysgo welcome screen
return to the boot loading screen "Nitros9 Boot" and repeat this
forever. When debugging with gdb (which ideally shouldn't change
anything) I sometimes get a graphic screen with ever changing contents
- probably from something writing all over including the SAM
registers.

Tormod