5 ms·

What can one do with 200 gates? I struggle to think of anything interesting.

r3013 4y ago
I suppose it depends on one's interests. For example one could try to clone many of these: https://en.wikipedia.org/wiki/List_of_7400-series_integrated_circuits https://en.wikipedia.org/wiki/List_of_7400-series_integrated... Another fun project idea. Make a 1bit processor slice. Then show how many slices can make a larger system. Similar to: "Using LSI processor bit-slices to build a PDP-11—A case study in microcomputer design" https://dl.acm.org/doi/pdf/10.1145/1499402.1499444 https://dl.acm.org/doi/pdf/10.1145/1499402.1499444
cmrdporcupine 4y ago
A full 6502 is only like 900 gates. One could do a neat project with separate ALUs chips, control logic, etc, like AM2900-style. From Googling, it sounds like the 74181 ALU chip was only ~75 gates or so https://en.wikipedia.org/wiki/74181 https://en.wikipedia.org/wiki/74181. And the AM2901 something like ~500
- tdeck 4y ago
  The PSP 8/s used only 519 logic gates, at least according to online sources I've found.
  - tdeck 4y ago
    Sorry PDP 8/s
    - cmrdporcupine 4y ago
      Yeah I looked at my keyboard and saw D beside S and figured that's what you're saying. Read the PDP/8 instruction sheet. Wow that's nice and minimal.
alain94040 4y ago
Maybe an idea: Could I use this to put a secret key in the gates, with some mechanism to prevent brute-force breaking? So my own personal Yubikey essentially. Not sure how to protect against replay, with only 200 gates...
- no_time 4y ago
  Could work if you are OK with hundreds of engineers seeing your key during the verification/manufacturing process.
amelius 4y ago
Hashing?
mysterydip 4y ago
It mentions a possible set of dip switches and a 7 segment LED. You could make a puzzle game of "lights out" where only a certain combo of switches would have all the segments off.
hugs 4y ago
"I could make a motor driver!" was the first thing that came to mind. I have a need for lots of motor driver chips for an art project. (Think hundreds or thousands of small DC motors.) At a minimum, a basic "h-bridge" circuit to control one motor is 4 transistors (and possibly 4 additional diodes). I'll still have to figure out if TinyTapeout could handle the voltage and current of one small DV motor, though. (5-12V, possibly up to 800mA). Of course, there are simple h-bridge chips already on the market for $0.20/chip, but designing my own would be fun.
- jononor 4y ago
  If one could integrate some logic that can be communicated with over a digital protocol it would get real interesting. Maybe it could be the start of an open source I/O chip for the Klipper 3d-printer firmware. The output stage could be using discrete SMD components, to get sufficient power capacity.

I suppose it depends on one's interests. For example one could try to clone many of these: https://en.wikipedia.org/wiki/List_of_7400-series_integrated_circuits https://en.wikipedia.org/wiki/List_of_7400-series_integrated... Another fun project idea. Make a 1bit processor slice. Then show how many slices can make a larger system. Similar to: "Using LSI processor bit-slices to build a PDP-11—A case study in microcomputer design" https://dl.acm.org/doi/pdf/10.1145/1499402.1499444 https://dl.acm.org/doi/pdf/10.1145/1499402.1499444

cmrdporcupine 4y ago

A full 6502 is only like 900 gates. One could do a neat project with separate ALUs chips, control logic, etc, like AM2900-style. From Googling, it sounds like the 74181 ALU chip was only ~75 gates or so https://en.wikipedia.org/wiki/74181 https://en.wikipedia.org/wiki/74181. And the AM2901 something like ~500

tdeck 4y ago
The PSP 8/s used only 519 logic gates, at least according to online sources I've found.
- tdeck 4y ago
  Sorry PDP 8/s
  - cmrdporcupine 4y ago
    Yeah I looked at my keyboard and saw D beside S and figured that's what you're saying. Read the PDP/8 instruction sheet. Wow that's nice and minimal.

alain94040 4y ago

Maybe an idea: Could I use this to put a secret key in the gates, with some mechanism to prevent brute-force breaking? So my own personal Yubikey essentially. Not sure how to protect against replay, with only 200 gates...

no_time 4y ago
Could work if you are OK with hundreds of engineers seeing your key during the verification/manufacturing process.

amelius 4y ago

Hashing?

mysterydip 4y ago

It mentions a possible set of dip switches and a 7 segment LED. You could make a puzzle game of "lights out" where only a certain combo of switches would have all the segments off.

hugs 4y ago

"I could make a motor driver!" was the first thing that came to mind. I have a need for lots of motor driver chips for an art project. (Think hundreds or thousands of small DC motors.) At a minimum, a basic "h-bridge" circuit to control one motor is 4 transistors (and possibly 4 additional diodes). I'll still have to figure out if TinyTapeout could handle the voltage and current of one small DV motor, though. (5-12V, possibly up to 800mA). Of course, there are simple h-bridge chips already on the market for $0.20/chip, but designing my own would be fun.

jononor 4y ago
If one could integrate some logic that can be communicated with over a digital protocol it would get real interesting. Maybe it could be the start of an open source I/O chip for the Klipper 3d-printer firmware. The output stage could be using discrete SMD components, to get sufficient power capacity.