An interesting read; there's something really nice about the way older games do things (like this saved state encoding, or anti-cheat by referring to certain pages in the manual. In this age of cloud save (and I say this having worked on a cloud save product!), we've lost a level of connection here.
I was intrigued as to how one would even figure out the sequence of operations used to encode progress into a 'phone number'; a quick search turned up an in-depth report (http://www.dougbabcock.com/mtpo-passwords.txt) which doesn't appear to be credited in Allan's article. It looks like Doug used a password archive to figure out the steps as an exercise in cracking, which itself sounds jolly fun.
I was intrigued as to how one would even figure out the sequence of operations used to encode progress into a 'phone number'; a quick search turned up an in-depth report (http://www.dougbabcock.com/mtpo-passwords.txt) which doesn't appear to be credited in Allan's article. It looks like Doug used a password archive to figure out the steps as an exercise in cracking, which itself sounds jolly fun.