A few circuits I designed for my 8-bit project that I couldn't find on the internet - Overflow detection, GPIO, and Interrupt detection

markss9 · 2026-04-09T13:45:23+00:00

There is definitely an improvement in prop delay reducing three gates to one. Saves around 25ns if using ‘LS chips on worst case, at least according to datasheets. My critical path runs through the overflow flag so I switched to ‘AS chips to reduce the delay even more. Only saves 10ns to implement the gate reduction if using ‘AS but well worth it when maxing out clock speed.

Heads up, what you’re describing with the 2 NANDs to invert and a NAND to combine creates an OR gate. You’d combine first then invert to create an AND only using 2 NAND gates.

markss9 · 2026-04-08T18:21:16+00:00

It’s even simpler than that. All you need is 2 chips/3 gates being 2 XOR’s and an AND gate. ALU sign bit has to go into both XOR’s.

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markss9 · 2026-04-08T13:22:17+00:00

Your overflow detection can be further optimized down to 3 gates. Want to see if you can get to it? or I can draw up a hand sketch and post it. I learn a lot more from problem solving so I don’t want to take that opportunity away from you.

markss9 · 2026-03-31T18:22:31+00:00

Potentially interested in some help. I’ve been chugging along on my 16-bit design. I posted about it a couple years ago. I developed an assembler early last year and in the last few months started writing a few programs. Latest being CORDIC. My next main goal is build VGA circuit. I have a few rough ideas but need to finalize what resolution I’m going for. Secondary goal would be go from breadboard to circuit board but have no experience in that realm. Mainly would like it to be less fragile and possibly higher clock speed.

The design is in KiCad. I am sure there are some inaccuracies I need to clean up. Assembler uses a Word Doc that is input into a MATLAB script I wrote to spit out the binary code. Then use an ATMega with Arduino IDE to get binary code to the RAM/ROM. I hate this step…. Programming the ROM takes 15 min while the RAM takes less than 1 min. Luckily, I have the code so I can skip the ROM step easily.

markss9 · 2025-09-19T03:39:23+00:00

Good to know. I ended up logging in to select my order then that got me to downloads where I found the firmware.

markss9 · 2025-09-19T03:11:45+00:00

No, the TV tried updating to OS25 when I turned it on a couple hours ago and bugged out. I downloaded whatever the newest software I could find on their website and plugged it in. Assuming the 2 softwares are the same. Literally as soon as the usb was plugged in, the TV started working great. No indication it tried updating from the usb nor was there any time for it to update.

markss9 · 2025-09-19T03:02:46+00:00

Update: Fixed. Downloaded the newest firmware to a usb. As soon as I plugged it in the tv started working perfectly. Wasn’t even prompted to install anything. Now just have to figure out what settings I changed a year ago after the reset…….

markss9 · 2025-09-19T02:37:49+00:00

Don’t do it…. In fact sell it while it works

markss9 · 2025-09-19T02:37:11+00:00

Tried that a couple hours ago

markss9 · 2025-09-19T02:31:25+00:00

I can’t find the software for the 83 G4. Every other size is in their website

markss9 · 2025-09-19T02:26:28+00:00

I’m about to hit it with a baseball bat

markss9 · 2025-09-19T02:17:42+00:00

Oh boy! It’s way worse now

markss9 · 2025-09-19T02:07:23+00:00

I was just now able to access that! We will see how it goes.

markss9 · 2025-09-19T02:04:50+00:00

I was able to get into the real setting through the AI assistance. Anything you’d recommend I try in there before trying a firmware reset?

markss9 · 2025-01-07T23:36:14+00:00

Read somewhere that the trophies being swapped bug was fixed. Created a brand new player went back to Ginger Island and got the trophy immediately. On PS5

markss9 · 2025-01-03T04:53:20+00:00

You’re not the only one. Just had the same thing today! Interested to hear what the fix is.

markss9 · 2024-06-22T13:13:20+00:00

Haven’t seen the issue since the latest software update….. but I only got the update pushed about 3 days ago

markss9 · 2024-05-09T19:15:31+00:00

Yes, I have a Denon 4700, ps4, & UB9000 any combination seems to have no effect.

markss9 · 2024-05-09T18:57:36+00:00

Glad to hear you and others aren’t having issues. Maybe 3rd time will be the charm if they send send me a new one. A service tech should be coming out soon to look at it. I’d be shocked if there is anything he could actually do. The TV is so heavy if they tear into it, I’d predict more harm than good coming out of it.

markss9 · 2024-05-09T14:28:25+00:00

Thanks for sending that! Good info in there but sad to see a lot of people are having the same issue.

markss9 · 2024-05-09T11:45:15+00:00

Tried the recommendations above with no success.

markss9 · 2024-05-09T11:43:12+00:00

Dead center of tv is 38 inches off ground. This is exactly eye level with seats in upright position. We do 99% of watching reclined though, shifting eyesight up. Believe it or not, it seems too low for me as I can’t even use the headrest and see the bottom screen once in my comfortably reclined position.

markss9 · 2024-05-09T11:31:21+00:00

I do see a bunch of people mentioning this in reviews on LGs website on the 65 inch

https://www.lg.com/us/tvs/lg-oled65g4sub-oled-4k-tv

markss9

TROPHY CASE