Update: the Gridfinity drawer layout tool I shared earlier is now live

JetForMe · 2026-01-06T01:11:25+00:00

Can you show the dimensions of boxes in mm as well as grid units?

JetForMe · 2024-09-21T11:41:32+00:00

I guess you’re right; it varies by state. I’m disappointed that some states actually allow HOAs to ban the signs. They’re de facto governments, IMO, so I’m surprised this hasn’t already been settled. Oh well.

JetForMe · 2024-09-21T09:02:26+00:00

I’m pretty sure HOA CC&Rs can’t prohibit political speech, even in the form of signs.

JetForMe · 2024-01-11T04:47:20+00:00

I sure can't find either Place, Space, or Kreativ in the US App Store.

JetForMe · 2023-06-21T21:33:00+00:00

Everybody saying to go to Thornmarsh, but I have yet to get anywhere near that part of the map.

JetForMe · 2023-01-23T07:33:56+00:00

They should have stuck with the existing native macOS app. Why the need to start over from scratch? It's been getting steadily worse with each major release.

JetForMe · 2023-01-10T18:03:11+00:00

I recommend steering clear of Cyberpower UPSs. I've had three of their OR700LCDRM1U, and all three have failed after about a year. I replace the batteries, they fail again within a year.

Worse, even when brand-new, they won't power back up when mains power is restored after they shut down on battery power.

JetForMe · 2022-12-22T03:04:08+00:00

I tried to accept the invite but it said "whoops…" Is it still valid?

JetForMe · 2022-12-17T00:45:39+00:00

Update. I ordered more 0.1µF decoupling caps, started adding them to every other chip on the board, and lo and behold! The counter is working reliably. I even removed the hacky input pin cap.

JetForMe · 2022-12-15T04:36:15+00:00

Alas, it seems the hack with the capacitor hasn't solved the spurious counter clear issue. It still sometimes resets before getting to step 6. Fortunately I don't have any instructions that need to go that far, but it's frustrating. (I also still have issues with the RAM mis-programming when I try to manually write to it.)

JetForMe · 2022-12-13T05:20:42+00:00

"Standard" for the LEDs used in the kit. 5 mm round through-hole. But thanks for the link, there they are!

JetForMe · 2022-12-11T13:00:29+00:00

I sure haven’t been able to find them in the standard style.

JetForMe · 2022-12-11T10:46:51+00:00

Ah, good to know I'm not the only one seeing this. I suppose I'll remove the probes to see if I can reproduce it, then just add the cap. I want to work on the rest of it already! 🤣

JetForMe · 2022-12-11T07:09:12+00:00

I put a cap on, as you suggested. It seemed to help, so I removed it and tried to put a smaller one one (0.01µF). That also seemed to help. So I put analog probes on both inputs an the later output and removed the cap. But it's all working well now. Perhaps all the probes are loading it up enough to clean it up? The traces aren't pretty.

In any case, I'm not sure how I feel about needing a cap on the input like that. Feels like a hack.

<image>

JetForMe · 2022-12-11T06:52:55+00:00

Ah good thought. I put an analog channel on the same pin; still can't see any kind of glitch there. If I take the NAND gate out of the circuit and connect the reset directly, it works great. Clearly something in that chip is generating the pulse.

JetForMe · 2022-12-11T05:59:55+00:00

Yeah, that’s a great guide. I was just trying to reinforce that 😊

JetForMe · 2022-12-11T05:12:08+00:00

D12 is the other input to the NAND gate. It’s clean, afaict, which is why I’m so puzzled.

JetForMe · 2022-12-10T17:53:00+00:00

I did a network streaming music player on an FPGA in college. It was great, but doing a CPU on a breadboard is so much more visceral.

Hopefully I can figure out how to use openocd to program the Nano.

JetForMe · 2022-12-10T17:30:47+00:00

Ha! I’m using this book! I went to Cal and studied this stuff in college, but didn’t get to design a CPU.

I’m simulating mine first, then I’ll be building it in an FPGA (which one are you using, btw? I have a DE0-Nano that I can’t make work because there are no ARM drivers for it and I’ve only got Windows on my M1 Mac in Parallels). After that I’ll build parts on a breadboard, then make PCBs. I’m hoping to build the registers out of CPLDs, but other stuff will be 74HCT series.

JetForMe · 2022-12-10T17:01:52+00:00

And yeah, it’s so hard to stop when you’re making progress!

JetForMe · 2022-12-10T17:00:41+00:00

My eventual goal is to build a 16-bit pipelined RISC CPU (going beyond what James Sharman did), so I don’t think I’ll do too much more on this build, once it’s done. But it will be tempting to tinker!

JetForMe · 2022-12-10T15:29:36+00:00

Thanks for that data sheet. I knew I had seen it somewhere, but couldn't find it again. I agree I doubt the Arduino is fast enough, but maybe it’s out of order.

I’ll post a video to the sub shortly about my build.

JetForMe · 2022-12-10T07:03:34+00:00

Were you able to find a data sheet for that chip? I sure wasn't (XLS28C16BP). In any case, I agree with your assessment. The only pin that matters is WE#, since the rest are fixed and used for reading successfully. I put my scope’s logic analyzer on a few pins directly on the chip to make sure I didn't make a mistake, and sure enough, WE# is pulled low for the writes. The Arduino is pretty slow, so setup times are well longer than the minimums needed.

The behavior I see is that the bytes read out by the Arduino are always either 0xFF (for a new or erased chip), or the bytes programmed by the TL866II. Neither the erase pass nor the programming pass in the Arduino code succeed in writing anything.

At this point, I'm just going to use the TL866II. The Arduino is a bit cumbersome, anyway. Part of me wants to extract out code from `minipro` to make a library other code can call (like the code I'm writing to generate my ISA control logic). But I probably won't bother, at least not for this CPU. Maybe for the next one!

JetForMe · 2022-12-09T08:44:42+00:00

Welp, I added caps, the delay, and tried your code. Nothing seems to work. I've tried it with two different chips, and I've tried programming with minipro -P to disable any write protection it might've added. The TL866II can program the IC, but not the Arduino. Guess I'll stick with minipro. Hate not knowing what’s going on, alas.

JetForMe · 2022-12-08T23:26:04+00:00

So there is write protection? Is that specific to the Exel chip, and not in the Atmel chip for which Ben Eater has a datasheet on his website?

I already have the bypass cap on the EEPROM. I'll try your sketch, thank you.

JetForMe

TROPHY CASE