[Coco] Upgrading RAM for CoCo 1

[Zippster]

Don, 

If you haven’t done so yet, definitely pull all the socketed chips in the CoCo and reseat them.
Machines that have been sitting a long time often develop contact problems that are easily fixed this way.

I just had a machine the other day with no sound.  Reseated the appropriate chips, and now everything works.

Very common issue.

- Ed



> On Apr 25, 2015, at 8:15 AM, Dave Philipsen <dave at davebiz.com> wrote:
> 
> It's probably just corrosion or whatever.  If you had arcing like that across the pins on your DRAM chips you've got bigger problems. Other than the power supply pins, the signal pins on the RAM chips carry very little power.  Definitely not enough to cause arcing.
> 
> Dave Philipsen
> 
> 
> On 4/25/2015 7:37 AM, Don Akins wrote:
>> Ahh, thanks for the info. What made me think the chips were bad is that they
>> have scarring on the pins of some of them as if they arced from a short.
>> 
>>>     On April 25, 2015 at 12:20 AM Arthur Flexser <flexser at fiu.edu> wrote:
>>> 
>>> 
>>>     You realize that it's normal for PRINT MEM to show something like 8K in a
>>>     16K CoCo? (PRINT MEM is only showing the memory available for Basic
>>>     programs, which doesn't include 8K or so reserved for the operating
>>>     system. I think 8487 is what you should see with Extended Basic). If you
>>>     had bad RAM chips, the CoCo likely would show garbage on screen if it
>>>     booted up at all.
>>> 
>>>     Art
>>> 
>>>     On Fri, Apr 24, 2015 at 10:19 PM, donald at dra.space donald at dra.space <
>>>     donald at dra.space> wrote:
>>> 
>>>     > Hi Guys,
>>>     >
>>>     >
>>>     > I recently bought a silver CoCo 1 and when I booted it up it only
>>>     > recognized 8k
>>>     > ram out of 16k. So I opened it up and noticed that some of the ram chips
>>>     > appeared to have burnt out. The motherboard has jumpers for 64k so this
>>>     > board
>>>     > must be one of the later revisions of the CoCo 1. I pulled one of the
>>>     > chips I
>>>     > out which is a 4116N-3GP. Are there any equivalent 64k chips out there
>>>     > today for
>>>     > a CoCo 1?
>>>     >
>>>     >
>>>     > Don
>>>     >
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