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Second Dimension PCB's

Posted: Tue Oct 02, 2018 10:18 am
by Munkyears
Hey guys,
As per current development of a game that im working on using SGDK (based on a popular japanese anime movie, WITH trademark and copyright permission gained from a world famous japanese art studio...all will be revealed in a few months)

I bought these PCB's that support M27C160 & 322's. Just wondering if anyone has used these in particular? Image

Looking for a reliable source of 50 PCB's to start with.
I have a decent amount of capital funding for this project however the eprom supply chains are extremely limited, I can only procure small quantities of new EPROMS yet ancient chips are in abundance.

Any advice would be much appreciated!!

Re: Second Dimension PCB's

Posted: Tue Oct 02, 2018 12:38 pm
by TmEE co.(TM)
PCBs aren't a problem, main thing is EPROMs. You can mostly only get pulls, meaning they're been used before and their state is often unknown. Those chips haven't been produced for many years now and eventually the supply will run out, leaving dodgier and dodgier parts left until those are gone too.

Re: Second Dimension PCB's

Posted: Tue Oct 02, 2018 4:53 pm
by cero
Consider Krikzz Flashkits if you don't need SRAM. They use modern flash and have good availability, and no soldering.

Db-electronics considers them bad since they use resistors though.

Re: Second Dimension PCB's

Posted: Tue Oct 02, 2018 10:00 pm
by Chilly Willy
Not as bad as some of those Chinese boards that hook 3V memory straight to the edge, but not as good as using level shifters.

Re: Second Dimension PCB's

Posted: Thu Oct 04, 2018 5:11 am
by Munkyears
Good to see youre still around Tiido!

Thanks for your replies, I'm trying to keep flash carts away from this project. Similarly to recent projects, I would like something permanent.

I have 50 on hand and ordered a batch of 500 to begin with.

While I wait i am currently blanking 15 eproms at a time. Quite time consuming so i plan on ripping apart 8 UV erasers and constructing my own erasing bench.

Does anyone know the optimum distance from bulb to chip?

Im getting a failure rate of around 20%. Think some of them have had their day. Most are working perfectly with being baked for 2 mins at a time.

All the UV eproms are 322's. Some in varying condition. Sad, considering the current NAND flash shortage, Can't we go back to using this tech??

Re: Second Dimension PCB's

Posted: Thu Oct 04, 2018 12:09 pm
by TmEE co.(TM)
EPROMs are no more permanent than NOR Flash. Both work on same sort of principle and will degrade in same sort of manner. EPROMs will last less though, 50 years is probably the maximum while most chips I have looked at give 40 year rating. NOR flashes are usually rated for over 100 years.

Re: Second Dimension PCB's

Posted: Thu Oct 04, 2018 3:58 pm
by Chilly Willy
Over on discord, we've been talking about a cheap flash cart for small projects. It would use a 1Mx16 or 2Mx16 NOR flash ($1.28 and $2.13 in single units at Digikey), and like five 74LVC541A level shifters (5 x $0.36). You could have a header or an edge on the top for programming. Nothing special, just cheap and cover most types of games.