[Coco] "Ultimate" CoCoSDC Image and Cave Walker problems

[Robert Gault]

Barry Nelson wrote:
>   Were you doing this on a real CoCo 3? It runs on emulation, but not on hardware. I will try without doing a chx.
>
>> Robert Gault robert.gault at att.net
>> Sun Feb 14 20:45:49 EST 2016
>>
>> Barry Nelson wrote:
>>> Here is what I have. One program, CaveWalker, does not work. This has nothing to do with the CoCo SDC, it does not work under NitrOS9. To my knowledge, everything else works.
>>> This image includes games, utilities and applications.
>>>
>>> <snip>
>>
>> Barry,
>>
>> You have probably made the assumption that you need to chd games/cave and chx
>> /dd/games/cave/cmds. If you do that, the game will not run.
>>
>> Try the following.
>>    1) boot NitrOS-9
>>    2) cd games/cave
>>    3) switch to /W4
>>    4) enter   cave
>>
>> When I did this, the game started and seemed to play normally.
>>
>> Robert
>
>

Barry,

Yes I had been running the program from VCC. After receiving your message, I 
tried running the program with the .vhd mounted in DW4 from a Coco3 by two 
methods. Neither one worked as the system froze each time.

1) Boot NitrOS-9 from a disk on the Coco3 and
chd /X0; chx /X0/cmds
xmode /W4 par=1 pag=10
shell i=/w4&
cave
NitrOS-9 freezes.

2) Created a new boot disk and backed it up to drive #250.
Start HDBDOS for Drivewire with the .vhd mounted in DW4.
RUN"LINK:253" and tell it to use drive 250.
DOS250
NitrOS-9 started via DW4 normally with complete access to the .vhd on DW4.
Switched to /W4 and entered   cave   .
Again the system froze.

I can see two reasons for the freeze. With the #1 test, the programs would be on 
drive /x0 and the programs may have been hard coded for /dd. With test #2, the 
programs might be using $FF20 for sound or something that interferes with the 
dwio driver.
I can't think of any other obvious causes for a freeze.

Robert