[Coco] [coco] OS-9 CRC check

[Robert Gault]

L. Curtis Boyle wrote:
> On Wed, 06 Feb 2008 16:48:36 -0600, George Ramsower  
> <georgeramsower at gmail.com> wrote:
> 
>>  I don't know, but I thought the CRC check in OS-9 L2  would ensure 
>> that  a module was okay to use. I feel that this may not be the case 
>> as this  morning, I had a problem saving a file from Basic09. It just 
>> wouldn't  stop trying to save it.  I let it try for several minutes. 
>> It would move  the floppy drive's head back and forth and finally, I 
>> reset the CC3 and  rebooted. Once done, using Basic09, I reloaded a 
>> backup of the stuff and  saved it as I did the first time and it worked.
>>
>>> From Basic09...
>>
>>
>>  Save* filename
>>
>>  did not work
>>
>>  Reboot, restart B09
>>
>>  load filename.bu     << that's the backup
>>  save* filename
>>
>> Worked. How is that?
>>
>> George
>>
> 
> To speed up module loading, etc. quite a few of us disabled the CRC  
> check... it could be that your version of the Nitros9 kernal has it  
> disabled by default. Boisy?
> 
> 

Or CRC checking may have nothing to do with the problem. Every computer 
gets hit with electrical spikes or cosmic rays that can change memory 
content. The Coco has no internal method for periodically checking 
memory content, so you will be guarantied failures of this type every so 
often.

There may have been a bad contact to the controller at the cart port, 
dust on a head rail, or something similar causing disk I/O to fail. If 
the drive got stuck, it may have done so in a way that OS-9 could not 
recover.

I see nothing in your description of the problem that indicates module 
CRC checking would have prevented it.