[Coco] Blank PCB for EPROM-Based Cartridge

[Mark J. Blair]

On Sep 26, 2013, at 07:19 , billg999 at cs.uofs.edu wrote:
> Assuming a reasonable price, I would be interested in a number of them.
> And, I assume the more made in a run the cheaper the run becomes, right?

Uh-oh, it looks like we have multiple hardware guys named Mark here now! Feel free to call me by my ham radio callsign (NF6X) to avoid confusion. :)

Ok, regarding my EPROM board that Al talked me into: It's just a simple board to let folks use whatever old EPROMs that have laying about, and I don't see it as being much of a competitor to a fancier flash-based board once that's out of the gate.

I don't expect to make any money off of this simple EPROM board, and I'm releasing the files under GPLv3. I'm using this simple design as an excuse to try out a small-run PCB shop called OSHpark, in particular because they provide ENIG surface finish. In other words, gold plating, which is nice for the card edge fingers. They also have a feature on their web site called "Shared Projects" which is geared towards this kind of project in which I just want to give it all away and be done with it. Once I verify that the thing actually works, I'll put the design in their Shared Projects area so anybody can order up the bare boards without involving me at all. Their pricing for these small runs is $5 per square inch for 3 boards. So, ordering would be in multiples of 3 boards, and each bare 2.1"x1.75" board would end up costing a little over $6. Boards would have purple solder mask, gold surface finish, white silkscreen on both sides, and plated holes. Beveling the card edge would be a job for the buyer.

Maybe I'll make a for-profit CoCo-related product someday, but this particular project is a freebie for the community that I'm using to test out this PCB fab that I've been interested in. I expect it'll have some limited interest for a while, then fade into obscurity once the Cloud9 flash boards (?) are on the market.

I'm changing the board to add a couple of jumpers to allow up to 27512 EPROMs to be used, by the way. I'll be pushing the revised files to GitHub sometime within the next day or three, and then I'll fab up a batch of 3 boards for me to test out. If they work right, then I'll push it out to the OHSpark shared projects page, and y'all will be on your own to build them! :)

Here's the OSHpark Shared Projects page for anybody who's curious:

http://oshpark.com/shared_projects


-- 
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/