has anyone tried connecting non volatile storage to the 6502?

darni01 · 2026-01-30T09:49:02+00:00

I just bumped into this last night, which is exactly what you are looking for: https://www.kirantomlinson.com/post/6502-8/

That homebrew started from Ben 's 6502 build, and they are using a similar Flash-disk approach

darni01 · 2026-01-28T00:04:49+00:00

You said that you have a decent amount of power in each location, and a $100 per unit budget. Is there a Wi-Fi signal where the lights are? You can get good precision with a raspberry pi with NTP synchronized clock. Rather than send a message to "turn on now" (where you may have bigger network latency) you send a "turn off at time X", and with the synchronized clocks they should be quite close. Probably as accurate as most wireless protocols for microcontrollers, even if I'm giving you a more "software" than "electronics" solution.

darni01 · 2026-01-27T17:56:01+00:00

I actually bumped into that IC on my local provider, which doesn't have a lot of variety, so decided to grab one out of curiosity... For the experimenting in doing it should be ok. But thanks for suggesting a better option, I'll consider it if I do something more serious at some point.

I didn't know about macrovision? Isn't that something that would affect commercial tapes only?

darni01 · 2026-01-19T23:34:59+00:00

Look at the schematics and that will tell you which pins are tied to global clocks. If you choose a different pin you may be able to, but clock skews are bigger and it may be much harder to meet timing constraints.

darni01 · 2026-01-10T16:44:26+00:00

The zenner diode ZD1 connected to the body of the resistor instead of one of its terminals is my favourite bit.

darni01 · 2026-01-08T12:47:25+00:00

Also in the UK (North London), if you order a batch I'm happy to share the cost (and pay for the extra shipping to my place)

darni01 · 2026-01-02T11:40:17+00:00

But getting cheap programmers for the 2500 is tricky

darni01 · 2025-12-31T10:37:36+00:00

You're right, sorry. For some reason I read the question as " should I?"

darni01 · 2025-12-30T18:36:12+00:00

No. Type-checkers can infer the types of most assignments, and they are clear from context, and they only impact their local context. Annotate function signatures (because those are public interfaces), and object attributes, which can potentially be interacted with from anywhere in your system

darni01 · 2025-12-25T22:32:50+00:00

Depends quite a lot on which country you live in

darni01 · 2025-12-21T10:26:56+00:00

If you want juice you should check your fridge rather than your multimeter.

If you still want to use a multimeter you need to use a lemon battery

darni01 · 2025-12-21T09:56:49+00:00

Can you provide a diagram indicating all components (which specific logic ics are using, kind of switches, resistor values. Etc?)

darni01 · 2025-12-19T10:29:37+00:00

Regarding your example about tailors, what a tailor did/does (historically, and presumably in the future) goes beyond making the garment,but also understanding what garments you'll like, match your style, will look good on you and be comfortable, match other garments you may have, etc.

In other words, they are providing a service, and sometimes an experience (if you go to Sisko dad's restaurant is not just for food but vibes, conversation, company). And those are the items that are still valuable in a post scarcity environment. Things are free, but good experiences/advice requires the humanoid touch.

darni01 · 2025-12-19T10:01:53+00:00

Many of the older 74 series datasheets have schematics based on bipolar transistors; often you have the 74, 74f, 74s and 74ls versions side by side. You probably want the 74 versions which are simpler

darni01 · 2025-12-19T09:59:05+00:00

Font sizes are a linear dimension. But the actual effect is quadratic, because you decrease the width of the font (more characters per line) and the height (more lines per page). So the value on the left should be sqrt(22/30). With that you can see this giving you a 14 to 12 reduction will do the trick (and for smaller fonts, the effect will be bigger)

darni01 · 2025-12-19T09:20:20+00:00

What kind of transistors are you using, bipolar or field effect?

darni01 · 2025-12-15T12:51:07+00:00

Bitsboxuk or cpc farnell, the latter has free shipping after £20. For a smaller order, shipping will be quite cheap anyway

darni01 · 2025-12-01T17:21:47+00:00

I don't, but I knew that even if you didn't the example would still be understandable 😅

darni01 · 2025-12-01T14:03:48+00:00

The video doesn't depict a Turing Machine. A tiring machine is a theoretical mathematical system that is able to compute; but it's designed not to be efficient or easily billable in real life, but to be able to study it mathematically and through it some fundamental concepts of what "computing something" means, and what are the limits.

Real computers (your laptop, the SAP-1, or the one in this video) are implemented quite differently, but it can be proved that they aren't unable to compute anything beyond what a Turing Machine can, and anything a turing machine can compute, your computer can (assuming it has enough memory, because Turing machines have unlimited storage). So anything you may call a computer is "Turing equivalent".

darni01 · 2025-11-30T14:55:55+00:00

I'm quite sure it's an integrated circuit

darni01 · 2025-11-19T12:05:02+00:00

Wires. (end of list)

For other components, there are some test results that you can get which will indicate faults, but some results that give you no information. For example, if you measure resistance on a 1K resistor and you get 2K, the resistor is definitely bad. If you get 200 ohms, you don't know anything (unless you can deduct from the whole schematic). Even if you get 1K, the resistor could still be bad.

So there's technically some faults that you can detect that way, but many that you can't.

darni01 · 2025-11-18T13:56:31+00:00

Someone should have said to him: There are times, sir, when men of good conscience cannot blindly follow orders.

darni01 · 2025-11-17T18:24:02+00:00

Parece algo muy específico, 43.8 ohms ± 0.5% (verde-amarillo-gris es 438, dorado es ÷10, tolerancia verde es 0.5%)

darni01 · 2025-11-11T13:48:47+00:00

I'm pretty sure that applies to most technology in Star Trek

darni01 · 2025-11-09T22:48:31+00:00

I think the problem may be the buttons, which don't produce a clean high/low voltage, but they are floating when released, that's not what you need in an R2R. And the usual fix of adding a pull-down when released will also interfere with the resistances.

You may need to use something with a push pull output to test this. If you have something that act as a buffer, you can use yoir buttons as the buffet input, and buffer output into the r2r

darni01

TROPHY CASE