I don't know what's in the FPGA, and I honestly don't know that much about FPGAs, but I imagine it's a pretty much "drag and drop" of the Lisa logic board schematic rendered in whatever FPGA language is used, while leveraging as many, stock, "off the shelf" cores as necessary.
It's telling that they externalized the UART, since they couldn't find a core to use, and weren't comfortable creating one from scratch. Otherwise it's likely a 68000 core, and a bunch of logic gates, or higher level combinatorial logic ICs (directly rendered into FPGA language, or, perhaps, they drag and dropped a, e.g. shift-register IC core).
But the point is that FPGAs are that accessible today.
Add to that the board manufacture. This is no hobbyist through hole exercise. Get the board, break out the soldering iron. No, this was built in a modern electronic assembly facility. Cheap enough to do one off boards, vs runs of 10s or 100s.
Available to the every man.
Impressive achievement for the developer, but impressive we're in a place that this is a practical thing to try and do.
They've been accessible for a lot longer than most people think. The original Minimig project (an FPGA recreation of the Amiga chipset, coupled with a real 68000 CPU) started in 2005 - more than 20 years ago! And 15 years ago there was already a complete Amiga core (chipset and CPU) running on the Terasic DE1 development board, the C-One FPGA computer, and the Turbo Chameleon 64 cartridge.
Today's FPGAs are certainly more affordable and more capacious (especially in terms of DSP and RAM blocks) but the biggest shift is that, as you say, it's now possible and affordable to have the complete PCB assembled in short runs, which is a real blessing given that so many FPGAs come in BGA packages.
It’s neat that there’s such passionate Lisa fans out there. If anyone here is a current day Lisa enthusiast, I’m curious what makes you interested in it.
The thing that blew my mind as a kid on the original Lisa was the power button. You pressed it and it didn’t immediately cut the power like a PC, it was a request to cut the power and the OS would first clean up various things on the desktop before finally cutting the power on itself. It just seemed to have agency and a type of control over itself and its environment that gave an impression of intelligence.
I didn't correct for inflation but I wanted to buy the Lisa before it was released, it felt around 40000 Dutch guilders, maybe 80 times more expensive than this FPGA?
I did a few more back-of-the-envelope calculations of what I can do with these 2MB SRAMs:
Xerox Alto with Smaltalk-80 and Smalltalk-76 for $4. The Alto was the 1972 machine the Lisa tried to be the sucessor of.
Transputer T414/T800 for $50 but much faster than the original. You would make a supercomputer interconnecting hundreds of Transputers.
Vextrex without display but HDMI output for $50, $8 without the CRT/VGA/Oscilloscope, $100 with the cathode ray tube display built in.
200MB SRAM with 16000 cores 180nm WSI (Wafer Scale Integration) emulating most processors at $1000. It would outperform 2025 Blackwell NVDIA and Apple Silicon M3 Ultra Mac Studio because SRAM is faster than HBM or LPDDR5. It is much cheaper than the 2MB Sram on this Lisa FPGA (it costs around $25 per 2MB (16 Mbit) in batches of 1000 chips).
1. Wow! That's so cool!
2. Why didn't someone this smart spend that time to build something that really matters?
I really want to adapt what I've done into an amiga500 accelerator board.
Cycle-accurate software emulators are great (for example people have made drop-in "hardware" CPUs [1,2] which are actually implemented in software on a microcontroller) but FPGA-based implementations are interesting not only in that they create a very realistic and usable version of the hardware, but also because an RTL implementation shows how the logic design could be implemented in hardware.
And modern FPGAs have tons of gates, more than enough to implement an entire system from the 1980s.
The macOS Finder has its own version of the Lisa's stationery feature:
File > Get Info > Stationery Pad
https://youtu.be/1kshrfvkLZE?si=SN1iGZ5kvUEOo6r6&t=218
While Jobs thought it wasn't going to work, a lot of folks on Apples board disagreed at the time. A controversial character at times, yet both Jobs and Woz provably understood their customers better than most. =3
Unfortunately the Mac cut a lot of corners for affordability. The original Mac had only 128K of RAM, and Jobs didn't want to offer memory upgrades (he thought you should just buy a new computer - sound familiar?) It took Mac OS 16 years to get memory protection, which LisaOS had in 1983. Lisa didn't need to die - it could have merged with the Mac and made the latter a better and more reliable platform, years before Mac OS X.