[Coco] VCC 1.17

[Roger Taylor]

At 06:09 PM 2/24/2008, you wrote:
>You've hit a debug message that (I thought) should never happen.
>It happens when DirectDraw successfully locks the secondary draw 
>buffer but doesn't get a pointer back. As far as I knew untill now , 
>that was imposible.
>what should happen is either the lock should fail or you get back a 
>real pointer to memory. I've got a couple of Vista machines I can 
>test this on and should have it fixed in the next release assuming I 
>can reproduce it. I have a feeling MS changed the API a little in 
>vista so I have to handle this condition now. Thats for letting me know.


I use VCC a lot each day and it's a great and simple to use 
emulator.  What Robert Gault and I have discovered, though, is that 
somehow it keeps on ticking just fine when M.E.S.S. or a real CoCo 
bombs out under certain situations...

The big problem that took almost two weeks to get around was when the 
real CoCo 3 wouldn't read the joystick correctly if the PIAs are not 
set up exactly right.  I'm not even sure what control bit was at 
fault, but the real 3 would read back a slightly different range of 
values, or wacky results, while VCC always gave a correct joystick 
sample.  M.E.S.S. gave the same expected results, correct joystick reads.

All along Robert's CoCo 3 was causing my mouse cursor to jump all 
around the screen, not reach the borders, stick to the edges, etc. 
and it was almost impossible for me alone to figure it out since I'm 
using emulators exclusively for program development from the Rainbow 
IDE.  I finally decided to just read the PIA values that BASIC has 
set, then reset/set only the bits I need to control, then store the 
values back.  Things started working on the real 3 and the emulators 
at that point.

It's definately true that unless emulators mimick every glitch or 
hardware "feature" of the real machine, that development shouldn't be 
done totally using emulators.  Periodically one should run their game 
or app on a real CoCo before it gets too late to locate bugs easily.

My problem with M.E.S.S. (the version I use) is that the joystick 
results are way too sensitive compared to Window's mouse cursor.  VCC 
is perfect, however.  M.E.S.S obviously isn't considering that the 
PC's cursor is now inside of the emualor window and should scale the 
PC's mouse range down.

Btw, can (or will) VCC launch from the command line into virtual 
disks like M.E.S.S. does?  If you can get close to how M.E.S.S. does 
it, one should be able to point to vcc.exe instead of 
mess/messgui.exe from the Rainbow IDE to launch into their built 
disks or programs.  What about ROM images?