Don Hodges analyzes classic arcade games like Pac-Man, Donkey Kong, and Galaga at the code level, finding and fixing bugs.
HN commenters recommend it for explicit low-level details on arcade games, including kill screen patches and ghost AI bugs, with the non-arcade pages to be ignored.
The linked Don Hodges article about Level 256 is particularly fun to read, complete with a few proposed patches & a way to make the startup checksum still pass:
http://donhodges.com/how_high_can_you_get2.htm
A fun quote - it certainly seems better to have an ending, even if it is not intended:
> "It is probably a good thing that Pac Man has this bug in its program. If it didn’t, expert players could conceivably be able to play the game indefinitely, because whenever they get tired they can just park Pac Man in the hiding places and leave the game to go eat, sleep, or whatever, and then return to the game and continue playing. The only limiting factor would have been the length of time that the game could run without a power outage or suffering from some other hardware failure. Experts would have been able to play the game for weeks, months, even years, or more."
This is an interesting set of articles, given the renewed interest in 8-bit arcade games recently (cough cough PAC MAN). Ignore the non-arcade stuff:
http://www.donhodges.com/archive.htm
This all looks like child's play now, but 30 years ago this was cutting edge engineering. These arcade board sets generated pretty great games for the era without framebuffers (RAM was hellishly expensive), high-speed CPUs, or a lot of other conveniences we take for granted today.
There's been a few interesting articles posted on HN about Pacman's internals and gameplay:
http://www.donhodges.com/how_high_can_you_get2.htm
http://gameinternals.com/post/2072558330/understanding-pac-man-ghost-behavior
http://home.comcast.net/~jpittman2/pacman/pacmandossier.html#Chapter_5
You can find the relevant HN discussion by searching HN algolia:
https://hn.algolia.com/?query=pacman&sort=byPopularity&prefix&page=0&dateRange=all&type=story
The links to Don Hodges site are great if you want the explicit low-level details. For instance, he has a patch to fix the kill screen:
http://donhodges.com/how_high_can_you_get2.htm
I made a much less serious patch -- a backwards-facing Pac-Man that places dots instead of eating them:
http://members.shaw.ca/gp2000/bacman.html
If only things were that simple. A demo video can show that there is an interaction that doesn't stutter, not that there is no interaction that stutters.
For an historical analogue: you can show hours of paying PacMan without finding its kill screen (http://www.donhodges.com/how_high_can_you_get2.htm)
Here's more than you ever wanted to know on the subject:
http://donhodges.com/Controlling_the_barrels_in_Donkey_Kong.htm
http://www.jeffsromhack.com/products/donkeykong_tech.htm