Note that the OP added the last sentence after Andy answered. And that specific sentence did say alot about the OP.

If the OP had big reasons to program this chip, a good answer is completely different from if the OP wants to create a new project based on one or two chips on the shelf.

Maybe because the OP had 200 units of a product with this chip and a late-found bug that needs to be corrected but with the programmer lost. But that would then have been a very good time to tell that fact, instead of adding that rather meaningless final sentence to the original post.

I don't see a reason to stop people from wasting their time. But I would see it reasonable that people do mention that there are normally better ways to skin a cat. We do know for a fact that current-generation microcontrollers are very cheap to buy. And that some of them have very affordable programmers also available. Programmers that may not just fill the chip with code, but also allows the user to debug their chip.

So what I find offensive isn't when someone wants to program an old chip. But when someone says "take a hike" if they get good advice.

What you, Richard, is always missing is that the "why" is often the most important word when helping people. Only by knowing the "why" will you know what is a good solution.

Back to your example.

What would be the difference if that "why" was:

- I have this very unique car from 1937 that I want to spend two years converting into mint condition because I just love cars, and this model was the first car my dad bought. By the way - I have four other veteran cars I have restored before. The only issue with this one is that I haven't found any tyre company making the correct dimension. Anyone know about a company that custom-makes tyres?

or

- I have very little money, but just have to get a running car to get to/from work. I happen to have a wreck of a 1937 car standing outside behind a magasine. I don't know anything about cars, but since 1937 technology is simple compared to todays, I assume it must be quite trivial to get the car running again quickly and for a very low cost. So - where do I start?

Notice the big difference between the two scenarios? For sane readers of such requests, the two original posts would most probably take very different directions.

You, on the other hand, seens to always settle for "run ahead" even when you do not see any explanation of any "why". There is one group of forum visitors that tends to have that same view. That is students. They see everything as a technical challenge, and are willing to run with the ball without first considering if it's a good idea or if it would be many times better to take one or two steps back and instead try to solve a completely different - but much simpler/quicker/cheaper - problem.