Recent content by hideehoo

Pin 1 on the 4116's should be -5V (and pin 1 on the 1771 at U102 should also be -5V). Power for -5V is derived by the 1N751 (5.1V zener) diode at VR1 dropping the -12V power supplied on the left most pin of the power connector. I would check for -12V first and make sure you aren't feeding that...

$25 "Project" I picked up at VCFMW last year. Black screen, but did have a video signal, so I started by swapping the PLA with a NeatPLA since they are a only a few bucks to build these days. Still no dice so I broke out my other VCFMW purchase which was a used FLIR ONE Pro. Looks like...

My understanding is unlike the BigBoard which will route terminal output to either the CRT/keyboard or serial port depending on which one receives input first, you can can't redirect terminal output to the serial port on the 820 and it expects to always have a keyboard and monitor. I seem to...

I bought these from this seller years ago when I was first acquiring parts for this years ago. https://www.aliexpress.us/item/3256803066939310.html Looks like they are still available. There is also this guy who advertisers a cheaper "domestic" substitute...

Stencil wasn't worth it to me given I was only building one or two boards and there aren't any challenging tiny components or fine pitched TQFP packages. For the top I just used solder paste via a pneumatic dispenser and then finished on a hot plate. Bottom was done with an T12-KU tipped...

Nice! Please share your updated binaries if you don't mind.

That's been an open issue on the Flash Floppy project for years now. Some work was done, but never really merged back in or taken to completion. I figured with the new Artery chips with more memory, dual drive support would get some love again, but I guess not...

Did a small update to the custom Flash Floppy board. Now has a speaker for cheesy disk sounds. :) https://github.com/djtersteegc/OpenFlops-Ferguson

Thanks for sharing, I'll add them to the disk images in my repo.

No enclosure yet, just some 3D printed standoffs to keep the board off the bench/table. Not really happy with them since you get a bit of sag given the size of the PCB, so maybe someday I'll buy a laser cutter and do a plexiglass sandwich with cutouts for the various ports on the top. Similar...

Congratulations!

There shouldn't be a jumper there, that's just two vias (untented for authenticity). The left side connects to AC and the right to GND. Solder jumper to provide (optional) power to the floppy pins 4, 6, and 8 is on the back of the board near pin 4.

What was the issue? Bad EPROM's?

And here's the final working setup. I'll get design files and documentation up on https://github.com/djtersteegc/Xerox-820-Projects once I have a little more time. I have lots of extra adapter PCB's, so if you're in the US and need a set (or two) for a couple of bucks, drop me a DM.

PCB order is in, time to assemble everything. First order of business was a power supply. This is based on the case design I used in the Big Board with a Meanwell RT-65B just without the hole for the reset switch since there's one on 820 motherboard. Next up was the keyboard adapter, also...