Maybe of interest to those involved in this thread..
A code review of PoP :) Probably not that much in there the seasoned 6502 hackers didn't already know.. But an interesting read over a coffee..
http://fabiensanglard.net/prince_of_persia/index.php

Here is Prince of Persia Code Review Part 2 ...

I spent a bit of time today cross-referencing opcode maps to come up with the following routine, 20 bytes long and with no branches whatsoever, which produces a (vaguely) human-readable ASCII code in the accumulator indicating the type of core it's running on:
.P65C02
TestCPU:
LDA #0
STA $84
STA ...

Thanks for your reply.

Ah, it seems the domain expired. Fortunately, the Internet Archive has captured the content:

http://web.archive.org/web/20191020113930/http://www.swtpc.com:80/mholley

http://web.archive.org/web/20201005074340/http://www.swtpc.org/mholley/Microprocessors/Electronics_Jul_24_1975.pdf
http://web ...

Help has arrived! Phil Pemberton noticed the new site location:

Looks like it's moved to http://www.swtpc.org:

http://www.swtpc.org/mholley/index.html

And the PDFs you mentioned:

http://www.swtpc.org/mholley/Microprocessors/Electronics_Jul_24_1975.pdf
http://www.swtpc.org/mholley ...