[Coco] Software testing for FDC emulator

[Robert Gault]

Darren A wrote:
> On 4/22/11, Robert Gault wrote:
>>
>> OK, what specific information do you need about 7th Link?
>>
>
>
> I need to know exactly how the code interfaces with the FDC hardware
> to figure out why the emulation is failing.  Now that you have shown
> me how to invoke the MESS debugger, that procedure should be much
> easier.
>
> I thought it was quite interesting that the behavior you describe
> under recent versions of MESS (screen shifted horizontally) is the
> same that I a see with the FDC emulator on a real CoCo 3.
>
> Darren
>

Well I could send you what I've managed to disassemble of the boot code.

7th Link does not use any of the disk ROM code. I has its own NMI, timing, 
read/write, and error routines. There does not seem to be anything very unusual 
about the code. The boot disk is 40 track with a structure that prevents the 
BACKUP command from working. That normally means track/sector IDs or size is not 
normal and the type of error determines how to read the data.