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Boards arrived right as I was heading out of town, so I finally was able to get one assembled today. Still need to get the MCUs programmed and do some testing... but it's otherwise complete! I'll have GitHub links posted here when testing is complete. The SD card slot is a bit of a tight fit...

Thanks! I always keep my eye open for dead ones now that the TashTwenty exists. If I find another one, I'll send you a message! Also, good news - I have a dual-channel opto-isolator separating the interaction between your end of things that handles data and mine that drives the stepper, so...

Alright, here's what I've got so far; this should be the near final design for V1.0 of the Mega. I'm considering adding an optoisolator, and you'll see why in a sec. I need to do some more breadboard testing now that I have the stepper working, but I'm pleased with how things have progressed so...

No worries! And good catch - that would be a mistake; they should be the same as the others. Not sure how I missed that, lol.

This is kinda where I saw this going originally - not just a means of replacing dead hardware, but of also building a "new" Lisa altogether if one were inclined. The form factor really binds you to using a pre-existing Lisa chassis, so after all this is said and done I'd like to try to integrate...

I've actually been curious about this myself.

Okay, let's see how this looks: With this, no riser should be necessary. This layout should allow users to use the same card to do either of the following: Install an SD card slot on the interior-facing side of the PCB, while desoldering the DB19 from their dead HD20 and transplanting it on...

Oh man, I forgot you could put custom icons on there! Sorry, meant to respond yesterday and then the day went to hell at work. Noted on the enable lines - I'll get these fixed and post a shot of the EDA drawing for you to verify. As for the DB19s, I was initially thinking that folks would be...

Not dumb at all! The Mega is a re-implementation of tashtari's original design, so you would only have to have it and a small bill of materials (that are largely the same as the original) in order to make it work. The PCB is powered by the floppy port itself, so you wouldn't even need an...

As promised: Hope you don't mind, I took some creative license with the name. Instead of two LEDs indicating power and activity, this version XORs /ENABLE and +5V to one green LED to simulate the effect of the power LED on the HD20 blinking when activity is going on. This also eliminates...

They have arrived... ...and it's a perfect fit in the card cage. Should have one assembled by this weekend; wish me luck - this thing has over a thousand pads to solder, lol. @mg.man Eventually, yes! I'm working with AlexTheCat123 over at LisaList on some collective first revision stuff...

Thanks! Quick update for anyone following. Version 1.0 of the PCB is going to get a second set of eyes doing one last sweep and then it's off to fabrication. With the help of the person working on the I/O card, we (they, really) were able to figure out how the layer indicator transparency...

Well, almost two months later and here we are: Not visible are the two inner layers form +5V and ground (well, DGND). This is effectively 100% complete, but I'm trying to get one last piece of cosmetic flair to work before calling it done. The software I'm working with (EasyEDA) does not...

Oh dang! This reminds me, I need to draw up an HD20 replacement PCB! Almost done with the Lisa 2 CPU card; I'll start this back up once that's done.

Going to have to take a few days of after-hours progress off on this to rapidly install a drainage system for my yard before round two of heavy rain hits the DFW region this coming weekend. Spent yesterday digging a trench in my back yard to prevent my shop from flooding, so we're just going to...

Okay, small update... well, less an update and more just providing some reference images. They're a bit large, but they're a fraction the size of their TIFF parents. These are unfortunately only 400dpi; I have access to another large format scanner that can go up to 12800dpi (lol, each side of...

On to unfortunately bigger things! Next up is the CPU card and, boy oh boy, is this going to suck. First and foremost, a huge thank you to user jamesdenton over at LisaList for providing me with a busted CPU card, as he's allowed me to depopulate it and scan it for reference for this task. I...

As far as technique goes, I was able to get the solder out of most of the holes, but some - anything connected to an inner plane, for instance - were particularly stubborn. As the connecter had to be replaced and I didn't want to risk damaging any further pads/traces, I just mangled the...

Thanks! I used a Hakko FR300 to desolder it; it went fairly quickly, considering it's a four layer PCB and there's like 120 pins, lol. If you do a lot work on stuff like this and don't have one, get one. Of all the tools I own - electronic or otherwise - my Hakko is without a doubt my most...

Well hot diggety - that solves that mystery! Thanks again, so so much, for checking that! With that out of the way, I have a few final checks and then I think this thing is safe to call done.