_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

PCB manufacturers

Good to know. I use [url]oshpark.com[/url] - they aggregate PCB designs and do daily runs of 2-layer boards and somewhat less often for 4-layer boards.
2 layers: $5.00 per square inch, 3 boards (if your design is 1"x1" you get 3 boards for $5.00).
4 layers: $10.00 per square inch/3
free shipping
currently gold-plating boards although no promises
same disclaimers apply

_________________
In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

Zigzag traces... Since the FPGA is rotated 45 degrees, a horizontal 5mil trace cannot clear the pads. The closest you can do is a /\/\/ zigzag around every pin. Looked scary across 10+ pads.

_________________
In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

If not scary, at least tedious and error prone. I have access to PCAD and I don't like do that kind of routing manually with that tool unless it is necessary to make a patch without moving too many traces, and no components. Your solution of moving the oscillator is probably best anyway.

_________________
Michael A.

All you need is a regular IO pin. Since you only need 14 MHz max, it's easiest to use an internal clock at twice that rate, and just implement a toggle flip flop on the output.

Cleaning up the board. There are 15 extra FPGA pins now connected to tiny pads just big enough to solder a wire-wrap-type wire. So it's possible to do Garth Wilson's SRAM stacking.

I will order 3 boards this week. The heating elements for the hotplate are due to arrive as well - I have the PID controller, the SSR and aluminum ready to go.

If anyone cares to review, here is the GEDA PCB file:

http://apple2.x10.mx/6502play.img/6502playground.A.pcb





Minor changes include:
-1.2V regulator runs off 3.3V

_________________
In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

This is a really cool project - definitely count me in if it's not too late!

Not too late at all. I now have about a dozen XC3S700ANs and even more 128KB SRAMS. After testing (and probably making minor revisions) I should be able to bang out at least 10 units, $60 each for this forum.

I am working on an Apple II mainboard with keyboard, paddles, VGA or composite and CF slot. I hope you guys can make or help me make some other machines...

Send me a message and I will add you to my list.

P.S. I hope I am not violating any board rules. I am not soliciting business (as you can judge by the price that probably does not cover the component costs). 6502 machinery is more of a religion practice for me.

_________________
In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Finally the first prototype boards came in. A 100 Forint coin is for reference

_________________
In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

Any proress with your BGA project enso?

_________________
65Org16:https://github.com/ElEctric-EyE/verilog-6502

A family member died tragically and unexpectedly. I've been unable to spend any time on this project.

My hotplate seemed to work well, but the initial board failed to configure - as expected. I created a test board with just JTAG and power connections and a couple of leds. Fabrication was delayed with christmas/new year holidays. I haven't had a chance to try the test board. At this point I can hardly remember what I was doing...

I will try to get back to it. In the meantime if anyone wants the schematics/layout in gEDA format, let me know.

_________________
In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

I'm very sorry about your family loss.

Thanks for posting an update.

Your prior postings on BGA soldering using your custom hotplate config were most inspirational. I look forward to your future posts.

_________________
65Org16:https://github.com/ElEctric-EyE/verilog-6502

Condolences enso, no hurry.

Sorry to hear that enso: my condolences too.