Jecel, thanks for your reply. Inline.
On Jun 11, 2011, at 4:38 PM, Jecel Assumpcao Jr. je...@merlintec.com wrote:
Casey,
Here's a fun thought: while staring at the Visual6502 visualization, it
occurred to
me that the likes of Verilog and VHDL probably represent a rather tall order
to
new folks (like, hey, me,) and the idea popped in there.
(snip)
But did you actually understand the Visual6502 and not just the idea of
it?
Nope. But it struck me to be able to see it compute. I do think I took
something of value from the experience: I just don't know what it is yet.
I didn't, and I am reasonably familiar with that processor at the
schematic level and also an integrated circuit designer (I have created
a few chips at the rectangle level).
Even simple microprocessors are hard to grok, yes, because they're vast. The
next watershed, though, might be finding a relatively simple architecture which
is also fast.
Field programmability gives me a touch of hope that systems will be able to
optimize adaptively to the behavior of the user(s) driving, and evolution
itself is a pretty straightforward idea, but this is just a thought-example.
Most likely the shape it would take would end up surprising me. Biology is a
great place to look for working concurrent systems, at least I think so, so
hopefully that's a worthwhile thought experiment.
The problem is quantitative -
there are just too many rectangles changing color at once and there are
too many to fit in the screen at a reasonable size.
You have to blow them waay up, slow them wy down, and then focus on
units of things, I think.
Have you looked at the ALUs that kids have been making in Minecraft? You can
_walk around_ in there. Inside the simulated microprocessor, and actually watch
the electrons walk down the Redstone wire. And when you want the birds-eye,
a simple server mod lets you fly way up and look down.
It was the thing that jumped out at me and said: it's time, mortals can make
processors now, which means you can do anything. Quit your job and go, Case.
I probably won't have time to finish a design, but I'll have learned a lot in
failing, at least.
I really hate to deal with structural designs in Verilog or VHDL (as
opposed to behavioral designs) which is why I use TkGate.
I'm going to have to look up TkGate, because I don't know the difference.
Unfortunately,
we get into quantitative problems again with screen sizes. My hand drawn
schematics in the 1980s were always one to three pages of very large
paper. You needed a big desk to be able to fully open them up and you
could see both the big picture and details at the same time. It was easy
to quickly trace some signal from one side of the design to the other.
Imagine walking alongside the wire as the electron travels. While your view
is very limited to your specific locus of attention, you can zoom out. A heads
up display would probably help.
Now people do schematics on letter sized paper. The project is broken
down into some 20 or so pages. Each page has just one or two integrated
circuits (or subblocks) in them and wires running to the edge of the
page to connectors that indicate other pages. In other words, this is
a netlist and not a schematic and there is no advantage compared to the
same thing in VHDL. It has the disadvantage of taking up 20 pages to do
what VHDL would do in just 3.
Sure. So in this hypothetical Logo, which I'm calling WeeHDL like a right
parody, you should be able to do macroscopic things like what you do in
Verilog. We seem to have learned that different sets of metaphors help explain
different sets of problems.
The problem I have with Verilog seems to be that it's used to avoid thinking
about the very details that I hope to understand. I obviously want a lot of
abstraction, but I also want to able to understand the mapping between these
representations, which got me thinking OMeta, etc.
It dawned on me that I could probably make a little Logo where the turtles
draw
with metal ink. Has anyone tried anything like this before? Does it seem
like a
good idea to try it now?
You might like Chuck Moore OKAD system which is used to create the
GreenArray chips. The software is not available, but there are videos of
him giving demos of it. Mostly in his fireside chats:
Oh, I looked at their site the first day that I became aware that I wanted to
actually build a computer instead of keeping the blinders on about my hardware.
I didn't know that he was involved in that.
The TinyComputer jumped out at me as a system that I actually wouldn't mind
writing assembly on, and it's been a long time since I've said that.
Going to look at GreenArrays again.
http://www.ultratechnology.com/rmvideo.htm
http://www.ultratechnology.com/okad.htm
http://www.colorforth.com/vlsi.html
Note that the software evolved quite a bit from the early 1990s (when it
was a paint the rectangles style) to
