[Coco] 6309 port of NitrOS-9 Level 1

[Tormod Volden]

On Sun, Jan 25, 2015 at 12:04 PM, Tormod Volden wrote:
> 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

Thinking about it, an XRoar hard reset does indeed initialize the RAM,
so I am not sure what is going on here.

Tormod


> 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.