If you'd like to learn more about controlling Intel CPUs with Arduinos, you can watch my talk at VCF Midwest 2025.
https://www.youtube.com/watch?v=m_C7i44-yPE
It's kind of crazy that you can do this sort of thing without an FPGA. You really should use an FPGA, but hey.
I like to use Fritzing to plan my breadboard projects
here's my Fritzing layout for the 286 breadboard.
the DIP adapter is represented by a silly-big custom chip.
Fritzing doesn't have an Arduino Giga, but they have a Mega, which has the same GPIO footprint.
I think ultimately I need to move the Giga to the right side of the breadboard, that will let me make all the bus lines shorter.
If I've learned one thing about breadboarding, it's that short is good.
We don't want to try to just stick any old 82284 in - we need a CMOS version, since we're clocking things slowly.
Luckily 82c284's were made, like this one from Intersil.
The 82c284 can take a clock input as X1/X2 crystal inputs, or can can take a simple externally generated clock signal on its EFI pin.
How you tie the F/C pin determines which inputs it uses. We'll be letting the Arduino drive the clock via EFI, so we need to use a pull-up resistor on the F/C pin.
Now I'm playing the game of "Where did I put the thing I bought off eBay last year sometime"
If I had a dollar for each time I bought something again because I misplaced it after I bought it the first time I could buy more 82c284s
Found them!
Why did I buy four of them? Four-way SLI of course
@gloriouscow Short is good, but shorts are not!
Oct 31, 2026, 9:55 PM@gloriouscow … I’m in this photo and I don’t like it.
Now where’s those 4.7k ohm 0402 size resistors?
@gloriouscow I just bought two VIC2s only to find the other VIC2s I bought a few years ago when trying to pack them away.
@root42 I did this with a pcb order once, then I found the sealed package from pcbway where my cat had knocked it behind my desk
@gloriouscow I meed someone to organize my parts for me. I am hiring. Pay is bad though.
Nov 1, 2026, 1:24 AM@gloriouscow it's with that one digi-key order you've been looking for for the past month.
@gloriouscow It's next to the thing from ebay you forgot you bought.
@gloriouscow nice. I should try using fritzing again for my little projects. Didn't get on with it last time I tried.
@gloriouscow hey, doing a 286 board is on my bucket list. do I really need that funky timing chip?
You probably want the funky timing chip.
The 286 needs clock-synchronized RESET and READY signals. The 82284 lets you input asynchronous signals and it produces the CPU clock with the right duty cycle and aligns the edges of READY and RESET for you.
If you don't align RESET the CPU won't start properly. Things will glitch out.
@RueNahcMohr If you're driving that stuff with a microcontroller or FPGA you can do it yourself, of course, but why not use the chip that was made for the job if you have the space for it?
@gloriouscow do you think I can pull it off with a CPLD? I'm not sure I pulled those other chips when I scrapped most of my 286 motherboards.
@RueNahcMohr probably. But you can get them on ebay
Shipping to Canada: ONE MILLLLLION DOLLARS!!!!!!!!
@RueNahcMohr the price of living in a functional democracy
@gloriouscow well, that if I'm lucky, most sellers in the USA wont ship to foreign countries like Canada.
yeah, i didn't, when i was still selling stuff on eBay.
because it's ridiculously expensive and Canadian buyers don't seem to understand you're not just screwing them over because you feel like it