I want to design what would have been a super computer in 1975, using parts that would have been "easily" available. Several people have done this already, just not on an insane scale. My favorite is the Magic-1, which I'm currently designing PCBs for. It has been a GREAT learning experience studying the schematics from the Magic-1. I never thought much about what a computer did during the mysterious clock cycles between instruction cycles, and now with the microcode muxes, registers, it all just makes sense.
Any way, I need my computer to be very good at math. The magic-1 is a16bit Add/sub/compare machine. I want to make mine capable of 32bit operations and have a 32 bit data path.
I'm starting with 32bit multiplication because it gets 32bit addition out of the way as well.
I threw together a diagram of a 32*32 multiplier using around 1040 AND gates and 400 74283 Adder circuits. This schematic would be what I think is called "asynchronous".
Once I completed my diagrams I remembered something horrible. There is a LOT of time spent waiting for the carry-in-out propagation in the hundreds of adders which leads me to building an adder out of XOR and AND gates. This comes at the added expense of power consumption board space, but should speed things up by about 250x. Could anyone suggest the best 1 bit addition "block" with carry? Its pretty late here and I'm starting to loose brain function.
Crazy? Remember, a few weeks ago I completed soldering 19,008 LEDs to make a display...which I haven't finished yet... (building the drivers)
One last thought for those of you who, well, you know who you are. Idle, what would the power consumption of some 600 odd ICs be? 20ma per device? This just might make more heat than a pentium!
Now...for floating point... ;)