A great advice one gets at around minute 9 is to place footprints for anything you consider remotely possible or that you'd like to test. You can always leave them unpopulated and the tradeoff between area lost and time lost is usually worth the area, especially in the first iterations of a pcb.
Computers need more blinking lights.
It was crazy when it was running. You could visually debug a bus, if you wanted to.
There would be some kind of main / idle loop. When this was running, you could see the pattern in the data buss and in the address buss. The loop of code would not be many instructions, they would all be together, so the pattern on the address buss would be quickly repeating.
If you had a slow peripheral, you could see the ISR getting called. It would be at a different address than the main loop, and you could see it flash periodically, like every time a line went to the printer.
As an operator of the system, you had a unique perspective of watching the program run as the system operated; if it was data processing it would not mean much but in a control system it was uncanny.
I would never use blue LEDs though.
(I thought he was going to end up with R2-D2; the way the design was going…)
This is still a partial build, so things might change a bit.
For me, I think it’d be cool to have the boards back to back so LEDs would always show.
FOUND IT! https://archive.org/details/1982-10-byte-magazine-october-1-...
Steve Ciarcia, CIARCIA’S CIRCUIT CELLAR
BYTE Octover 1988, A Supercomputer Part 1. Steve begins a supercomputer project by looking at multiprocessing basics.
https://archive.org/details/1982-10-byte-magazine-october-1-... (page 283 in the magazine, page 315 in the PDF)
BYTE November 1988, A Supercomputer Part 2. Steve continues the supercomputer project with a look at the Mandelbrot set.
https://archive.org/details/eu_BYTE-1988-11_OCR/page/n465/mo... (page 399 in the magazine, page 466 in the PDF)
BYTE December 1988, A Supercomputer Part 3. This final part looks at hardware nuts and bolts and also at the driver program.
https://archive.org/details/1982-10-byte-magazine-october-1-... (page 327 in the magazine and PDF)
And this thing is 10-13 cents ~30 years later.
A better comparison would be the ARM CPUs you can get fairly cheaply today (eg the Broadcom BCM2712 in the RPi5) but they're way more capable than the CPUs of 30 years ago. The BCM2712 for example is a 64 bit quad core 2.4GHz CPU.
I guess I'm just amazed at how far hardware has come because I'm old enough to remember just how amazing the 486 was at the time.
[1]: https://www.cnx-software.com/2025/04/02/10-cents-wch-ch570-c...
And yeah, that's wild.
?
Might be different if it was something truly useful or novel vs a nerd snipe.
Very impressive that he pulled it off in a relatively short amount of time.
The same way every diesel engine is just oil stove with side effect of rotary motion. If the engine was in the back of the car you could totally put a pot on it and braise something.
In fact they are converting 100% of it, they are just also collecting and moving additional heat in the process.
The heat pump takes input heat and just concentrates it. It turns out that the energy spent on concentrating heat also turns into heat, so you have a 100% efficient heater.
The 0.1% mentioned might be the light that the project produces.
What you may be thinking of is efficiency when the output is intended to be something other than heat. In those cases, efficiency is lost because a significant proportion of the input energy is converted to heat.
But if heat output is what you’re interested in, I’m happy to report that 100% is a perfectly achievable, in fact hard to avoid, number!
Essentially, light is one of the principal agents of entropy.