[Coco] Programs for NitrOS-9

[L. Curtis Boyle]

On Tue, 29 Apr 2008 12:37:21 -0600, Gene Heskett  
<gene.heskett at verizon.net> wrote:

> On Tuesday 29 April 2008, Diego Barizo wrote:
>> I was thinking more on programs that run in OS-9, but not on NitrOS-9.
>
> That should work, with possibly a <10% speed improvement.
>
>> Maybe it's just that I haven't been able to get them to run...
>> Most of the times I just try booting from NOS-9, and try to load the
>> program from the original application disk, that probably came with a
>> customized boot for OS-9.
>
> That is quite often the case, there might be drivers in their customized  
> boot
> that are not in your nitros9 boot.  vfy or ident should show those diffs
> though, and another boot might be constructed to add the missing stuff.
>
> ISTR there was a 1 byte patch to runb that played a minor role in this  
> too,
> but I can't recall the details now.  Perhaps someone else can find that?

    It had to do with error trapping, trying to read the error code  
register off of the stack. Because of the position of extra registers on  
the 6309 during an interrupt, the offset had to change. This affected both  
RUNB and BASIC09 itself.
    Some other programs (Home Publisher is one) also needed patches for  
similiar reasons. Others (like Flight Sim II) were patched for 6309  
versions so that they would run more efficiently. Basically, any program  
that installed it's own SWI calls would need patching, unless it only used  
the registers that didn't move (like CC) in the new IRQ stack frame.


-- 
L. Curtis Boyle