sje wrote:A while back I prowled through the DECUS (Digital Equipment Corporation User Group) archives and found a binary, at least semi-official in status, of MacHack. I was able to scan all the strings in the executable, but I didn't have a reverse assembler to read the actual code.
Yeah, those are the binaries for MacHack that I'm talking about.
It's uncertain what kind of modifications / hacks were actually done, so it would have been nice to have a copy directly from Mr. Greenblatt.
I don't even have a contact address for Greenblatt, so I can't ask directly. But as I said, from what I gather, the ComputerHistory.org people have been trying a couple years to get him to look for an original copy and he's resisted. If he's not willing to do it for them, there's no chance that he'd do it for me.
MacHack was different from most programs since then as its evaluation was strongly path dependent. As I understand it, the plausibility selection heuristics were also used to score the position. Quite a time saver in spite of some drawbacks.
The old style Shannon Type B programs actually did fairly well. If there was something obvious to do in a position, the program usually found the right move fairly quickly. The big problem was when a non obvious move was needed. The answer according to Paradise (and eventually also to Symbolic) is that a good plausible move needs to be generated as part of a plausible plan, and the generation of such a plan needs efficient and elaborate pattern recognition along with a big plan library.
I'd guess that CHAOS was probably the best real selective search program around, and even they moved away from pure to hybrid.
The Slate / Atkin / Gorlen Chess 3.6 was abandoned in favor of pure brute force.
I don't really know how well the classic selective search programs (CHAOS & AWIT) would run on modern hardware. It'd be interesting to find out, though.
Development of plans is a bit outside of my discussion ability, other than to say that I don't know of any program that was actually sucessful with making 'plans'.