Looking for 8 bit bus proto board system.

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The old 8 bit isa bus backplane and similar would be nice to switch in board modules. Searching the net, couldn't find much (a reference to "8bitbaby"?). A separate card slot for power, I/O, and CPU board is how it was done in ancient days. Thanks for any tips.

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Hi! I am not 100% sure this is what you are looking for but it sounds close IMO from your description. The N8VEM homebrew computing project has a Z80 SBC that can be plugged into an 8 or 16 bit ECB backplane for peripheral expansion. One of the peripherals is a prototyping board so you can make your own peripherals.

The ECB bus uses DIN 41612 for low cost homebrew prototyping boards rather than the ISA card edge connectors which tend to be specialized and more expensive. You can use plain DIN 41612 type 3 (A & C) connectors which are cheap and also phenolic Radio Shack style prototyping boards too. They are inexpensive for "one off" prototyping either point to point or wire wrap.

Just check out the N8VEM wiki and/or mailing list if you want more information. Full disclosure: N8VEM is my project and I am a hobbyist who enjoys making prototype 8 bit computers and peripherals.

IMO, I think it could easily be adapted for AVR projects and I've considered making some myself. We are working on a Propeller uC project at the moment.

I hope this helps. Thanks and have a nice day!

Andrew Lynch, 73 de N8VEM

PS, mods if this post is too close to "promotion" please delete and accept my apologies in advance.

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Take a look at the STD bus. But keep in mind that a typical microcontroller is probably not going to be a very good fit to most general busses.

Maybe your best approach would be to use STD bus protoboards, card cages, etc to come up with your own bus.

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lynchaj, when searching I saw the reference to homebrew but didn't follow up since I have a large folder named "homebrew" of Z80 files I've had for years. Probably have your work in the back of my mind.

I have some big old clunky eurocard racks from the 80s, some isa backplanes, etc. I just don't know. Maybe some old SIMM memory sockets.

Thank you both for the suggestions, I'll follow up.

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Hi! Putting the N8VEM homebrew project aside for a moment, I suggest that the ECB is itself a worthy bus for prototyping small 8 and 16 bit CPUs and uCs like AVR. You can purchase pre-made ECB backplanes (not N8VEM) in Europe or make your own fairly inexpensively.

The ECB specification is published, uses low cost 2 layer PCBs or prototyping boards. More importantly because it uses DIN 41612 type C connectors it is *much* cheaper and more reliable to prototype with compared to any of the card edge connector busses such as ISA, STD, and S-100.

I have built prototyping boards for a bus based system that cost around $8 each using Radio Shack style pseudo Eurocard prototyping boards ($5) and DIN 41612 connectors ($3). They plug into an ECB backplane made with female DIN 41612 wire wrap connectors using the same Radio Shack phenolic prototyping board.

I believe you can build an entire system for prototyping using off the shelf parts that will be inherently more reliable than any card edge connector based system due to the qualities of the DIN 41612. Obviously I am a big advocate as I think whomever designed the DIN 41612 standard must have been a genius. It is hard to beat cheaper and more reliable when prototyping.

If you use the ECB to establish your AVR prototype if you choose you can either just make all your own stuff or leverage the existing base of ECB designs completely independent of the N8VEM project. You could also use N8VEM boards or not that is up to you.

When I designed the N8VEM SBC, I purposely restricted its ECB bus interface to IO only although the ECB itself can be used as either an IO or a memory bus. There are many examples of ECB memory boards in magazines like C'T Projekt from Germany.

I hope this helps. I wish you the best of luck in your prototyping efforts regardless of what you choose. Thanks and have a nice day!

Andrew Lynch

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Hi Andrew. I agree with you mostly. I used the Eurocard system and like it for big projects.

As for small projects, I did find where someone is using SIMM slots for risers. And I found a great backplane company "protostack.com" that works with AVR development. Please check them out.

We both are interested in gaining circuit board real estate and modular design at lower cost. Please check out "protostack." If you have a pin suggestion please let me know.

Sincere best,
Rick.