[Coco] CoCo 3 RAM upgrade question

[Robert Gault]

Blake Patterson wrote:
> So, part of the haul of CoCo items I got in this recent package was a somewhat hacked up CoCo 3 bare motherboard with a 512K RAM expansion on it. I removed it and performed the upgrade to my main CoCo 3.
>
> http://www.flickr.com/photos/blakespot/6802978703/in/photostream
>
> To figure out the drill I looked over at Cloud9 for instructions on their SIMM board. It said to pull the 4 existing RAM chips and clip the upper C64 cap and the lower C65 cap. I noticed on the CoCo 3 that this upgrade came from that the C65 (lower) cap was clipped, but not the C66 (upper) cap. This is contrary to the Cloud9 instructions, but perhaps it's a different drill for different boards?
>
> The system powers up fine with the upgrade in it, but still I get just a few blocks read through DriveWire before it just sits there on almost every OS9 boot I perform using "DOS" command. Boisy thought maybe I was running out of RAM -- was hoping that things would be working now.
>
> Do I need to clip that upper cap? Is the RAM not fully recognized?
>
> Thanks.
>
>

Blake,

You have not given a clear description with "I get just a few blocks read 
through DriveWire before it just sits there." Do you mean the NitrOS-9 boot 
process fails or something else?
If boot fails, it may have nothing to do with the 512K upgrade. More likely, you 
are not mounting the correct boot disk in Drivewire. You must use a disk image 
with dw3 in the name indicating it was created specifically for Drivewire use.

I can send you a .dsk image with several RAM test programs on it. Mount that in 
Drivewire and you can test your RAM. Let me know if you want the test programs.