[Coco] IDE interfaces

Dave Philipsen dave at davebiz.com
Wed Mar 16 15:40:39 EDT 2016

I wholeheartedly agree with you.  It would take a lot of convincing to 
make me believe that gold edge connectors are going to wear out the cart 
port more quickly.  And almost all manufacturers of electrical 
connectors offer gold-plating as a means of making the connection more 
reliable.  I remember many years ago running my fingers across the 
contacts of those cheapo cartridges and getting a grey-colored stain on 
my fingers from the corrosion.  I've worn a gold-alloyed wedding ring 
for years and never had any kind of stain on my fingers from it.

My question to the Facebooksters would be: Why did Intel use gold 
plating on millions if not billions of their processors that were 
intended to mate with sockets?  Perhaps they could do a little research 
on galvanic corrosion and the anodic index of tin 
https://en.wikipedia.org/wiki/Galvanic_corrosion. An inspection of the 
edge connectors on three of my CoCo 3s reveals that they all appear to 
have some amount of gold on the contacts. At least Tandy got that part 


On 3/16/2016 2:15 PM, Zippster wrote:
> Gold edge connectors are bad, haven’t you heard?
> Just kidding, but there’s been a small discussion on the Facebook group where it’s being claimed
> tin-plated is better and won’t wear out your CoCo’s cart port connector as quickly as gold.  And that
> that is why Tandy didn’t use it most of the time, not because of cost.
> Personally I don’t  buy it, I think gold plated edge connectors are the way to go, even though they
> cost a bit more.  You can certainly argue it’s not necessary, but worse?  lol.
> - Ed
>> On Mar 16, 2016, at 1:47 PM, Dave Philipsen <dave at davebiz.com> wrote:
>> One thing I noticed about the MiniIDE is that there is no gold on the edge connector.  This is a mistake that shouldn't be repeated if someone decides to design a replacement.
>> Dave
>> On 3/15/2016 6:28 PM, RETRO Innovations wrote:
>>> It'd be interesting to see how small one could make the interface. If one used a flash ROM IC and a CPLD, I think one could put an IDE controller with IDE and CF into a 2.2"x2" form factor.  That's be small enough for any use, no?
>>> JIm
>>> On 3/15/2016 12:51 PM, Tormod Volden wrote:
>>>> On Tue, Mar 15, 2016 at 5:29 PM, Bill Pierce wrote:
>>>>> Some of the Brazillian Coco guys used the schematic from the Glenside unit and made a more "modern" solution that was smaller wih less parts (and fit the slot better). Maybe we could talk them into letting go of the schematic and get Ed to whip some up :-)
>>>> Here are some pictures of both the original Glenside board and the
>>>> Brazilian "MiniIDE": http://amxproject.com/?p=2585
>>>> Some people would probably prefer the big original with "integrated
>>>> MPI" and DIP40 chips, but I'd also be interested in the MiniIDE. Or
>>>> even a CPLD-based remake...
>>>> Tormod
>> -- 
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