There is also a listing for the micro-code. "micro-code" is the level
that is below machine code and it outputs
control words that control the H/W like selecting registers, enabling
data buses, selecting ALU functions, etc.
It usually takes a number of micro-instructions to implement a sincle
machine instruction.
Jack Eisenbach wrote:
Here's another "home built" computer. It's built out of 74XX series
TTL. :) You can actually login to this one.
http://www.homebrewcpu.com/
Paul G. Allen wrote:
Tracy R Reed wrote:
Amazing. I need to read up on how this stuff works and educate
myself a bit more. I would love to have a modern art piece like the
relay computer in that first link on my wall.
When I worked for Loral at the FASWP base (part of the old Naval
Training Center that has been closed for years and re-developed), the
fleet trainer I worked on was a mainly mixture of Relay Transistor
Logic (RTL), Diode Transistor Logic (DTL), Resistor Transistor Logic
(RTL), and some discrete Transistor Transistor Logic (TTL). There
were some tube circuits as well, but not too many (They generate too
much heat and take too much power to have been feasible in such a
system.) It was three stories of rack upon rack of cards full of
relays, old transistors, and diodes (not counting the power supplies
to power it all). Noisy as hell and broken all the time. It was used
to train carrier groups on coordinated sub hunting techniques. A huge
computer that could easily be replaced by a very low-end PC. Back
when it was built - in the '50s or '60s IIRC - it was a high-end
computer.
Relay logic is not any more difficult than logic based upon ICs. It's
all based upon ones and zeros, on and off. The power requirements are
much greater, there's a *bit* of a size difference, and the noise
level is just a *bit* higher. :o
PGA
--
[email protected]
http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-lpsg
