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Comment by rbanffy | Hacker News Reader

I wonder if that's enough to build a pocket Alto or Lisp Machine...

It'd be shocking if it wasn't, given that there's a number of FPGA based implementations of more recent and far more complex machines (in terms of gate count at least) than the Alto and early generation lisp machines, such as various incarnations of Commodore Amigas.

Some of them use external CPUs, but newer generation ones such as the FPGA Arcade can hold pretty much the entire machine include the CPU in the FPGA (usual exception is RAM, and a micro controller to bootstrap).

See FPGA Arcade, Natami, Minimig, C-One, Chameleon and others. Natami is the most capable of the bunch (aiming to be a faster, better Amiga), while Chameleon is probably the smallest (the size of an old style Commodore 64 cartridge, and can plug into a real Commodore 64, since it started as a C64 expansion on steroids, but it can run standalone too), with FPGA Arcade a nice middle group (fits in Mini-ITX form factor boxes, but isn't deep enough to fill nearly all of the box).

FPGA Arcade: http://www.fpgaarcade.com/ Chameleon: http://www.vesalia.de/e_chameleon.htm

So, what would be a good FPGA starter kit, just to learn how these things work?

Adafruit has an FPGA for sale: http://www.adafruit.com/category/products/451

I haven't tried it, as I have a much cheaper but far less documented CPLD sitting around, gathering dust. =p

I haven't tried this particular development board but it looks pretty inexpensive and would be a good starter board. http://www.easyfpga.com/

I've heard good things about the Papilio: http://papilio.cc/

To learn how FPGAs work, I'd recommend starting with a cheap Digilent board; see http://www.digilentinc.com/choosing.cfm - You can get a simple BASYS 2 board for under $100, possibly under $50. This board is the Arduino of the FPGA world. There are tutorials from many schools, lots of good documentation, it's a proven design...you can't go wrong with the Basys board. It does sacrifice performance for simplicity, though - Notably, there's no RAM except for what's on the FPGA. Go up to the Nexys for that, but if you're just interested in learning Verilog/VHDL, the Basys is a fine place to start.

To learn how these things work, get a job at a company which uses FPGAs. You'll probably never see one of these parts as a hobbyist.

If you're interested in stuff that's actually like this, and want to start right away, then look for a board packaged as a PCIe card. This will be significantly more expensive; think $500 on the extreme low end. NetFPGA is (http://netfpga.org/) is a good starting point if you're trying to start at a higher level. (Note that the old board is 33MHz PCI and the processor is obsolete; you want the 4x10GBE Virtex 5 part if you're looking for modern tools)

+1 for Digilent. They are a local company for me; they do really great hardware stuff at an affordable price.

The founder of the company is a pretty spiffy speaker as well; if you have a chance to see him, it's worth it.

I had pretty decent success with the products from KNJN (http://www.knjn.com/). It's affiliated with FPGA4Fun (http://www.fpga4fun.com/) which will help with the learning.

Recently I've been looking at the small, low-cost boards by XESS - http://xess.com/prods/prod048.php

Keep in mind that writing logic is quite different from programming. It's quite the mind-shift.

My interest with FPGAs is more designing processors rather than interfacing with electronics. I like the products from OpalKelly [http://www.opalkelly.com/] for this as they have a USB interface and C libraries on the computer side, HDL on the FPGA side to abstract the host->FPGA communication allowing you to just focus on your design.

If you're new to FPGAs or digital design in general, it'd probably be worth your while to pick up a good digital design book. I always liked Wakerly's Digital Design Principles and Practices. I recall that my edition (either 2nd or 3rd) was VHDL-focused, but it looks like the 4th edition has examples in both VHDL and Verilog.

There's also the matter of working through the FPGA toolchains, which isn't exactly a walk in the park. Unfortunately I don't have a good tutorial to reference off the top of my head...

I believe so. There have been some efforts to make a softcore[1] Lisp Machine, but when I last looked, it appeared that they weren't seriously pursued.

I would love to put together a softcore Lisp Machine. It would a tremendous learning experience and I think it could help spur some really interesting results in OS architecture. Particularly useful in that arena would be a multicore Lisp Machine.

It would be a dream come true if I got a job building such a device and development was open-sourced from day 0.

[1] Softcore, that is, a processor on an FPGA.

check this out, by hans huebner:

http://zslug.wordpress.com/2011/02/09/meeting-1-report-audio...

i had a few of the 3600 lisp machines, they wouldn't be hard to fit into a fpga at all (size wise, of course :). they had huge boards filled with chips, which were all... hand wirewrapped cmos chips (iirc) .

Yes. A $10 Spartan 3 could run a simple core and interpret LISP code. It's been done before, check Open Cores.

Been there a couple times. Emulating a real Lisp Machine would be a little more complicated than just a Lisp-running processor - you have miscellaneous hardware around it. I was imagining something software-compatible with a Symbolics or LMI with a USB port for keyboad/mouse, an SD card slot and an HDMI output.

Trivial. Those are comparatively tiny machines. This is at the level where you could simulate a Pentium or 21064 Alpha or the like.

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