[Coco] Nitros9 & Mess

[tim lindner]

Nathan Woods <npwoods at cybercom.net> wrote:

> >  I havn't yet, as OS-9 is a OS that is moduler and can place modules
> > anywhere in memory.  Although the bootfile is contiguous in memory,
> > finding RBF in that memory is a chore.
> 
> Yeah it is a chore.  If you have added debugging code to coco_vhd.c, you
> can add calls to activecpu_get_pc() to obtain the contents of the PC 
> register when those calls are made.

One thing I do is add an "Emulation Break" opcode to MAMEs 6809 CPU
core. Then download the source to NitrOS-9 and add "emubrk" instructions
to where you want the MAME debugger to break. Assemble a new NitrOS-9
Disk and bang, a break exactly where you need it.

The 6809 assembler used by the NitrOS-9 project already produces the
proper opcode for "emubrk": 11 FC.

If you want a copy of the patch I use, let me know which version of MESS
you are building and I'll send you it.

-- 
tim lindner
tlindner at ix.netcom.com                                        Bright