I was thinking about a simplified (minimal subset) 6502-style CPU build from 74-series chips as was done with minicomputers. I actually found that Jameco has a stock of 74S181 available, so it would be possible to use a couple of them and get most of the ALU functionality (everything but shift right, which can be done trivially with some shifted outputs). They're $1.95. I didn't think they were actually in production anymore, but they supposedly have about a hundred in stock with more expected in five weeks. I don't know if somebody like Rochester is doing small runs of them, or if somebody stumbled upon boxes of NOS, or what. That was a bit of a surprise. The bigger surprise was looking at the back of a bunch of issues from Byte magazine, and discovering they've been selling the 74181 and later the 74S181 for $1.95 for the past 45 years or so. Boggles the mind slightly.

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Thanks for pointing me there. I've already read several of Dieter's pages.

The page at https://tomnisbet.github.io/nqsap-pcb/d ... alu-notes/ helped me better understand the logical operations portion of the chart from the datasheet, because I wasn't seeing any of the ways I was used to seeing OR, AND, and XOR expressed; the overline/bar for NOT was at least clear. I'm used to seeing the ^ and v notation or the C-style notation. Apparently AB is A AND B, A + B is A OR B, and A (plus inside a circle) B is A XOR B.

I'm still not sure I'm going to actually build anything, but it does look feasible enough, and it has been an interesting intellectual exercise.

Sean, we already had some TTL implementations of the 6502 in this forum,
but it's always nice/refreshing to see somebody trying to take another/different approach on this topic.

No matter whether it actually results in working hardware or stays just "a paper project".
Good luck.

If you have any questions related to these old articles, just dare to ask, and I'm trying to help.
...Although my spare time is a bit limited, because I'm a bit deep into chip dissections right now.

Cheers,
Dieter.