Ask Chuck Moore About 25X, Forth And So On

Chuck Moore is, among other things, a chip designer. His latest design, the 25x, is based on a 5x5 array of X18 microprocessor cores, and could provide 60,000 MIPS with a production cost of about one dollar. And Moore has the chops to back that up: he's been designing tiny, efficient processors for many years. He's also the inventor of the programming language Forth, which has evolved from a miniscule but radically fast language "difficult for a human to read" (according to The Secret Guide) to the even more radical colorForth. How radical? Try "includes own operating system; has own 27-key Dvorak keyboard layout; meaningful color syntax." How's that for starters? Ask below your questions for Chuck about processors and programming (ask all you'd like, but one per post, please) We'll pass the best ones on to him, answers soon to follow.

Re:Using Forth as the intermediate

[Anonymous Coward]

I understand Forth is a stack-based language: doesn't that present problems when compiling for CPUs that mostly work using registers?

Indeed it does present a problem. In fact, it is a problem with any processor which only supports one stack, for example the 8085. Even the x86 family is not so hot for Forth, although the x86 can emulate some of the functionality of a second stack with the string load and store operations. Processors such as the 6809 are considered primo for Forth, but the Cadillac of all Forth processors is the Harris RTX-2000.

If you are interested in processors that are Forth-friendly, have a look at this [ultratechnology.com] processor round-up.

Re:Market Niche

[treyb]

60 BOPS is a fair value for a buck. But is the power consumption ridiculous?

From the web site: Max power 500 mW @ 1.8 V, with 25 computers running

Or is the only way to get this high of projected performance by clocking the chip like a six year old on chocolate frosted sugar bombs?

Again, from the website: asynchronous microcomputer core, meaning you don't count clocks like you do in synchronous logic.

My ignorance of Forth might be showing (one of the few I haven't had kicked into me over the years) - but wouldn't "meaningful colour syntax" represent quite a nasty disadvantage for those who are either entirely or partially (red-green) colour blind?

Chuck uses color, but you could change the colors to different fonts and/or font styles, if you want. Just as Python source uses indentation for telling the compiler about nesting levels, colorForth uses color tokens (think of it as a trivial markup language) to tell the compiler about word (aka function) definition starts, literal numeric values, etc.

Re:Forgotten interview?

[jamie]

"What happened to the 'Ask FCC Chief Technologist David J. Farber' interview questions (http://slashdot.org/interviews/01/01/22/1349237.s html) posted on Jan. 22nd?"

As Robin wrote in March, "Dave Farber agreed to a Slashdot interview back in January. I sent the questions but he never returned the answers despite several resendings and requests. Other than that, he seems like a decent guy."

Our comment/archive/search system is being worked on -- we're still fixing bugs for the 2.2 code transition -- but you can find that comment here if you'd like to verify: google cached copy [google.com]

Re:5x5 grid of procs

[John Sokol]

These CPU cores are on a single silicon die so there is no required (electrical) signaling method. Just address select lines. It's a direct register-to-register transfer at least in the original discussions that I had with Chuck about this.

There are a number of different mechanisms that have been discussed to signal the software, I'm not sure what Chuck has experimented with so far.

There is a group at MIT with a similar architecture only much less efficient.
http://www.cag.lcs.mit.edu/raw/

John L. Sokol