[Coco] NitrOS-9 newbie needs some help (Progress!)

[Robert Gault]

Nickolas Marentes wrote:

> Ok! Here is some more data I have collected...
> 
> 
> 1) Installation of the multi-pac interface improves formatting
> reliability...but still crashes system.
> 
> 2) When format fails, it doesn't just give an error message, it locks up the
> whole computer. Cold Reset needed.
> 
> 3) Tested formatting on both /D0 and /D1, same problems.
> 
> 4) 50Hz operation over 60Hz operation made no difference.
> 
> 5) NitrOS-9 failed to even boot with the 1986 GIME installed, boots with
> 1987 GIME.
> 
> 6) No problems actually writing files to disk or even doing a backup, only
> the format.
> 
> (and now the important one...)
> 
> 7) Tandy's OS-9 (setup as 40 track, Double sided)  works perfectly!! No
> formatting problems whatsoever!
> 
> CONCLUSION?
> 
> 1) My CoCo3 is most likely not perfect (possibly the RAM expansion
> tolerances?).
> 
> 2) NitrOS-9's formatter is "too fine with very little margin for fault".
> 
> 
> How does this sound so far?
> 
> Nick
> 
> 
> 
Some of these symptoms are hardware related and others software. You'll 
need to separate them to make progress.

Do you have access to a replacement PIA for the 68B21 IC4? Several of 
the cart slot lines go to this chip and if adding an MPI (buffering) 
helps then the 68B21 could be marginal.

There are timing differences between the GIME versions but they should 
have an effect on video action not disk I/O. When does the boot process 
fail with the '86 GIME?

The format disk I/O issue is strange. We need to know if any other PAL 
users are having problems with NitrOS-9. The same code you are using 
works on NTSC Cocos so the code itself is "good". If it worked on other 
PAL systems then the code would be good and your system hardware bad. If 
NitrOS-9 fails on PAL systems while working on NTSC systems then I think 
it is a GIME issue rather than a disk I/O issue but the NitrOS-9 code 
needs to be corrected.