I've had a chance to watch the video, and I have to say I'm really impressed (and really irritated so much of the content is over my head :) hardware design is really fascinating!). I think it's pretty amazing I that I got to learn about this new CPU literally a week after it went public!

I have very little exposure to networked chip designs so I'm not sure how widespread they are, but the Neo architecture reminds me somewhat of the GA144 Forth microcontroller, except "done right." For example, the GA144 lets chips communicate their own stacks (= data) to their immediate neighbors, but you can simply access the memory on another node with the Neo. That allows the worst-case scenario of "I need to access this data and I know it'll be a bit slow" - the compiler can simply work to try to organize memory so that happens as little as possible. The GA144 affords no such option; the other cores need to be instructed to send the data over. Cute design, but much harder to use (even ignoring the fact that the GA144 is Forth).

(As an aside, https://www.infoq.com/presentations/power-144-chip is an interesting (40:12) watch, FWIW. (The video seems finicky so I archived it at https://goo.gl/WGNjuA.) That chip apparently uses 7pJ per instruction. I'm very curious if that's any good nowadays.)

I'm curious if the address space accessible on a given Neo core is "windowed", aka if the address can be remapped. 17:28 says "static routing", but I'm unsure if this affects the memory map. I have the notion that being able to remap would allow for some interesting optimizations, but would add a nontrivial amount of overhead to the chip design.

I think it's awesome you're going to be as open as you can (1:14:40) and release the simulator (1:13:27)!

After thinking about the simulator for a bit, I thought it might be an interesting idea to get it into the education sector for generic "learn RTL" type classes: the hands-down fastest execution/turnaround time makes for a very good pitch and could be an interesting way to get your foot in the door of what I'm presuming is a well-established/entrenched industry, and from there that could be a nice way to springboard into other directions.

Plus, not only does the fastest simulator mean better student engagement, there's also the nice property that everyone who trains on it will collectively groan and weep when they encounter the current "cutting edge" at their first job... best case scenario, you'll wind up with a pile of people who learned on your simulator and want to do real-world stuff at that speed. :)

Idea you've probably thought of but which I'll mention just in case: offering your proprietary optimization stack as an in-house enterprise version for $oh_hey_everyone_can_retire_now, along with a $cheaper subscription compilation-as-a-service version that accepts LLVM bitcode and spits back binaries ready for the "load" command. This would neatly solve many IP issues at once because it's very, very hard to "rip off" an optimizing black box. That said, this makes for some interesting security and trust considerations.

While thinking about all of this I was distinctly reminded of the way POWER8 has propagated. I don't read too much about it on HN, and as Generic Tinkerer #23817 I'm not really too aware of its progress. I think I can safely assume the architecture itself has a laundry list of facepalms; my hope is invested in the fact that it's fairly unencumbered compared to x86, and I hope it goes far. Thing is, it's really hard for me to play with it. I know RunAbove used to have one or two (?), I think either IBM China or a university group in China is offering confusingly restricted public access to some, you can watch the POWER8 nodes in OpenSuSE's build farm. That's about it; there was also the Talos Secure Workstation, but that failed its crowdsourced seed round, which is a huge shame.

My point is that, the simulator is likely going to suffice for most people's interests and purposes, but for the few that want >1MHz (or ±300kHz on the kinds of machines that are likeliest to be widespread in generic education), well, it would be kind of cool for this not to wind up as yet another thing that only hotshots in big industries get to play with, because this thing runs at 1GHz already and looks really interesting.

I envision a possible solution as a simple, fast pipeline that accepts LLVM bitcode (or source code - that works too), compiles it, sends it to a dev board (sitting in a pool of of 3 or 4), and returns the result. Besides queue waits and actual CPU runtime, I can't see the extra steps taking too long, and in ideal circumstances users could probably do several iterations per minute. 4 or 5 cards could very probably fit in a 2U enclosure with 1U more for an x86 blade to run a web server. I have no idea if this sort of thing would be appropriate for this architecture, I'm only thinking about general exposure, educational access, etc - I'd expect that the industry has well-established communications channels and that most of the people that are likely to be the most interested in this architecture either know about it or will know very soon.

Regarding running Linux, I totally get the focus on bare metal DSP-type applications, but I do wonder if there are any potential performance gains to be had from a compiler and kernel (Linux or another) designed to understand software-defined memory management. I wouldn't be surprised if Linux wasn't ideal as a general-purpose OS; besides not really being great at hard realtime, I suspect an "SDMMU" would be difficult to elegantly wedge into the memory management because of architectural assumptions made by all of the code that might thwart the optimizations that could otherwise be afforded.

Finally - after hearing the bit about the CDC 6800 in 1:18:21, I thought I'd mention this just in case (might be boring/irrelevant): a few months ago I stumbled on a (real) PDP-11/70 running RSX-11M-PLUS and TCP/IP, with an open guest account that anybody can use. I mention this in case you're curious to study its I/O characteristics or whatnot (since it's a real machine). You could probably do pretty much any kind of test you wanted on it - I've found that its owners have no issues with rebooting/fixing crashes. Very happy to share details (to anybody!); my email is in my profile, I fear the machine would get trampled if I mention it publicly (on here) :)

(And shoutout to using Nedit. Haven't seen that in a while!)

Thanks for your reply, and thanks for reading :)