[Coco] Broken CC3

[George Ramsower]

>>>> On Friday 12 September 2008, George Ramsower wrote:
>>>>>Darn,
>>>>>
>>>>> My CNC coco broke.
>>>>>
>>>>> It starts up and displays the usual stuff. I can ?mem and it reports
>>>>>correctly. However, when I boot OS9, it crashes.
>>>>>
>>>>> I appears to crash when it loads the first boot sector.
>>>>>
>>>>>I tried other boot disks with the same results.
>>>>>I replaced the CPU, RAM board, reseated the GIME, polished the edge
>>>>>connector on the disk controller, reseated the ROM in the controller 
>>>>>and
>>>>>all gives the same results.
>>>>>
>>>>> Suggestions?
>>>>
>
> Does anyone remember why we modified the circuit at IC-9 to add a 74LS02?
>
> I'll try another '02 there, since it's socketed.
>

 This is interesting. The added chip on a spare CC3 board is an '02 but on 
the CNC coco it's an '04 chip. Since the latter was working, I'll have to 
assume it was supposed to be an '04.
I put another one in that socket and the CC3 is still broken.