[Coco] Nitros9 high speed mode

Robert Gault robert.gault at worldnet.att.net
Tue Jul 31 07:26:42 EDT 2007


Joel Ewy wrote:
> Robert Gault wrote:
> 
>>...
>>
>>It is possible for user programs to revert to 1MHz and emulation mode
>>with one important caveat. You can't let the system regain control
>>until you return to 2MHz and native mode. That means all IRQs should
>>be turned off, vectors saved, vectors redirected, speed and mode
>>changed, and IRQs restarted. This completely defeats the point of
>>using OS-9. You might as well write a stand-alone ml program to run
>>from Disk Basic.
>>
><snip>
> I once wrote a program to take 3 DS-69B Digisector video digitizer files
><snip>
> and write a 15-bit Targa high-color image from them
 ><snip>
> I wrote the program in
> C under OS-9 because it was a much better development environment (at
> least for this kind of thing) than DECB.
 ><snip>

Joel,
There is nothing in your example that would necessitate dropping the 
2MHz speed or leaving the 6309 native mode. So how does it relate to my 
quoted comment?



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