I was just thinking a few days ago, It’s been quite some time since we’ve heard from Retro Game Mechanics Explained. In fact, looking at their channel, it’s been eight months since their last deep dive into video game internals, their terrific (if somewhat dry) look into how Super Mario Bros. 2 stores and constructs its levels (1h40m!), drawing their tiles directly into a bank of work RAM specially included in the cartridge for that purpose.
Yesterday they broke their silence with an examination of the startup routines of arcade Galaxian, Teddy Boy, Joust 2, Pac-Man and Super Pac-Man. It’s “only” 41 minutes, but it’s hugely informative of the necessities of how and why arcades games go about arcading:
I will summarize. The main task an arcade machine must do upon startup is test as much of the hardware as it is able and confirm that it’s operational. The main part of this is testing the various memory types comprising the machine’s storage systems: audio, video and work RAM, and program and graphics ROM. Not just to test them, but to stop operation and alert the operator if something is awry. The garbage often shown on-screen on powerup is a direct result of writing and reading 0s and 1s to and fr0m every bit in the video RAM. The system must also check the contents of the ROM, which is usually done by adding all the values in each bank and comparing them to a known total, literally called a “checksum.”
It’s a fine explainer, even if they didn’t cover my personal favorite game startup, that of Twinbee and Gradius with the Bubble Memory system . The storage media of the game was unreliable unless it had physically warmed up, so when turned on it would play music while the game was making itself presentable, known fondly as the Morning Music. I posted about this way back in 2022! Here it is again. It would be an excellent tune to set a wake-up alarm on a cellphone. Just saying.
What I remember doing is working hard on a post proclaiming to the world the existence of a weird offshoot of the Pac-Man universe called Packri Monster. I wrote it, and I saved it (I believe) so it would be posted on the morning of January 16th.
Well, I just had a look and instead of the post I thought I had scheduled, there was just an empty shell, a title to an empty page. Even the name “Packri Monster” was misspelled. How embarrassing!
But what’s even more embarrassing is that I found out what I had written before had a notable factual inaccuracy, so I’m kind of glad it didn’t get out in that form.
Let’s remedy all of these things right now.
The Backstory & Coleco Pac-Man
Namco made the original Puck-Man, in Japan. Bally-Midway licensed it, changed the name to Pac-Man to avoid people messing with the P in the title, and that was when Pac-Man became a worldwide mega-hit. At the time game rights tended to get portioned off separately to consoles, home computers and dedicated handhelds. While (in)famously Atari locked up the console and (through Atarisoft) home computer rights to Pac-Man, the handheld rights went out to a variety of places.
Notably Coleco made (relatively speaking) a respectable tabletop version of Pac-Man, doing the best they could with its discrete graphic elements. You can play a recreation of that here. (Note: use WASD to control the game, the arrow keys are for Player 2.)
Coleco Pac-Man is interesting as a game in itself. Its box confidently asserts that it “sounds and scores” like the arcade game, of which I assure you neither is true. Its background noise is an annoying drone; while it usually takes two boards to reach 10,000 points in the arcade and earn the sole extra life, it took me five on my test play of Coleco Pac-Man. Even so, it’s the best handheld or tabletop version of Pac-Man from the time.
Because all of the LED graphic elements of Coleco Pac-Man’s are discrete, pre-made images, they had to take certain liberties with the in-game art. Pac-Man is drawn permanently facing left; alternate spaces on the board depict him with mouth open and closed. The dot image is repurposed as one of the ghosts’ eyes. Energizers are red, so when a ghost passes by one of those spaces one of its eyes, too, turns red. Ghosts don’t show up in different colors to identify their personalities. Each contains a Pac-Man graphic themselves, which isn’t illuminated when they are vulnerable. All of these elements are repeated throughout the board, visible dimly when inactive, and lit brightly when intended to be used as a game element.
I maintain that Coleco tabletop Pac-Man is playable. The simulation linked above has a flaw, you can’t hold down a direction to take a corner early like you could in the arcade, you have to press a key at the moment you sail past an intersection if you want to take it. But even in this form, it’s arguably a better game, in playability, than Atari 2600 Pac-Man. It sold 1.5 million units after all, despite coming out after.
It was a time when it wasn’t uncommon for companies to make ASICs (Application Specific Integrated Circuits) that could play one or more games, which they would license to other companies. General Instruments made a number of these for dedicated consoles (here’s a catalog of their products), playing a number of games, including Pong and Tank clones.
One such ASIC was made by Bandai, the same company that decades later would merge with Pac-Man creator Namco itself. It was made for a handheld that Bandai themselves would produce called Packri Monster.
Packri Monster as a Game
It’s an interesting little machine. Like Coleco Pac-Man, it uses discrete images for its graphics, which have to be mixed together in various ways to satisfy all of its play requirements.
Note the yellow letters on the package: PACK MAN. It’s obviously intended to be a fly-by-night knockoff, from the very company that would later merge with Pac-Man’s creator!
Differences are many. The maze is much smaller, the ghosts (“Bogeys”) are limited in number to three, and there’s only two “power foods,” in the upper corners of the maze.
The lack of one entire ghost makes sense, given the smaller size of the game. But it turns out there’s another knockoff of Pac-Man, with an even smaller maze, and a bizarre limitation. It’s the game I had originally mistaken for Packri Monster, and I wish I knew more about this variant, because it’s fairly widespread.
Mystery Handheld Pac-Man Variant #3
This version is probably best known as the basis of Tomy’s handheld Pac-Man game, in the appealing yellow case.
Tomy Puckman, using the original Japanese name and character art! Image from The Old Robots Web Site.
A simulation of Tomy Pac-Man is playable in MAME, and additionally can be found on the Internet Archive in playable form. It’s a simpler game than the Coleco version, and like Packri Monster tops out at three ghosts, starting at level four.
Especially notable about this version is its extraordinary difficulty, and dare I say, unfairness. There’s only 34 discrete places in the maze that Pac-Man can even be at, and two, later on three, of those places are going to contain ghosts at a time. From two to four locations can be threatened (“in check”) by the ghosts at any moment, for unlike arcade Pac-Man, these ghosts are more prone to reversing direction whenever they want. At the start of a board ghosts are prone to behaving randomly, so you can’t even devise patterns to ensure your safety. The Energizers become essential tools for survival, and expire rapidly, so you’re unlikely to ever eat more than two ghosts with one.
This is the only version of 80s handheld Pac-Man that I know of that has fruit. Graphic limitations mean that it’s always going to be cherries, but the points advance to 400 pts. per fruit on level four, where it becomes an essential component of your score. One extra life is awarded at 2,000 points.
But the weirdest thing about this version… since, like in all these versions, Pac-Man is stuck permanently facing left, and the dots are set between Pac-Man locations in this version, the unknown designer of Tomy Pac-Man decided that the player can only eat dots and Energizers when traveling left. The game isn’t about visiting every location in the maze, but visiting every dot when traveling in the right, that is left direction!
So if you’re fleeing from left-to-right, you’ll never eat any dots. It influences your travel significantly, and you’ll unavoidably often have to double back over dots to satisfy Pac-Man’s directional digestion.
When you pass level five, you get told: “good“. I don’t know if any later four-letter message await you. There aren’t enough elements for “wow”.
Like Packri Monster, Tomy version of Pac-Man’s got licensed out, but in an unusual format: at the basis for an LCD watch Pac-Man game from Nelsonic. Sum Square Stories shows off this version here. (8 minutes). There’s some substantial differences: it seems easier, scores much lower, and starts you out against only one ghost. But it retains Tomy Pac-Man’s most distinctive quirk, that eating can only be done when going west.
Why does this version of Pac-Man do that? To make the game harder? I have no clue at all. Can anyone enlighten me as to the reason?
Made in 1995 but not released until 2001, it’s really something. That is, it’s a thing, and there is some of it. Not only are the effects and acting somewhere beyond the line of rationality, it looks like it’s barely playable, even on the easiest difficulty. Imagine plunking down $50 for this in 2001 for your obsolete Sega CD, out of production for five years.
Huh…. on further reflection, that actually sounds awesome! The Playstation 2 had been released by that point! It’s certainly memorable, although I wouldn’t have wanted to buy it for purposes of playing it unironically.
Resurrecting Sinistar: A Cyber-Archeology Documentary is a 166-minute, that’s approaching three hours long, documentary about the effort to recover the source code of the Williams arcade classic, made by SynaMax.
SynaMax also made a modified version of the game that makes the notoriously difficult arcade game easier in various ways, in interesting ways.
I’ve been watching Awful Block on AGDQ, so that’s all I have for you today. Hopefully that’ll hold you over, although I suggest that you might want to watch AGDQ too, while it lasts.
Interactive Fiction blog Renga in Blue reports that a rare variant of classic Adventure, that was playable on Compuserve for many years and only went down when their game offerings went offline in the mid 90s, has been recovered and made playable online.
Promo image for this version of Adventure from Regna in Blue. You know it’s an adventure game in the70s & 80s when there’s a bunch of mostly naked people in the art.
It’s called Adventure 751 in reference to the number of available points there are to find. The post in turn links to Arthur O’Dwyer’s article on this version, and other versions, which seem to contain substantial added content from the original Crowther & Woods version.
It’s playable, but requires a lot of effort to get there, including compiling a PDP10 emulator and loading a disk image into it. I wish VCFMW wasn’t months behind me now, it’d have been a blast to see if someone there had access to a working PDP10, and if the game could have been transferred onto it!
As O’Dwyer mentions, there are plenty of games from this era that are just completely, utterly lost, with practically no chance of recovery. And even versions like this, that can technically be played, still hang on by just a thread. The people who created them often don’t have accessible archives, and the institutions who hosed them rare seem interest in preserving them. It’s a sorry state indeed, but at least there are a few survivals like this one.
Lists are severely worked content delivery methods, but darn it if TheZZAZZGlitch’s video lists aren’t actually really interesting. These are all early Pokemon game glitches and their application, and usually go quite deep into their code.
In the most recent of these (the ninth, 10 minutes long) one of the examples has to do with exploring glitched, out-of-bounds Pokemon boxes. These can cause writes to unexpected regions of memory, and very strange glitches indeed. But one in particular, if it happens, causes a write to a region of memory that causes an unexpected bankswitch, meaning, suddenly a whole swath of the game ROM isn’t what the code expects. In 99% of cases this would cause a sudden game crash end of story, but in THIS case the code that ends up executing doesn’t immediately crash the game, and not only that later in the code path, the bank gets switched back, and the code path is in such a place that it actually recovers, and the primary effect is just some glitched graphics, all completely by chance. Huh!
Here is that video, and if it’s interesting, the others (9 video playlist link) might be to your liking too.
And we’re off! Let’s start 2026 off with Flandrew’s look at the weirdest Star Wars game, the Famicom-only one Namco made. (11 minutes) It’s kind of a meme at this point, but gosh it’s even weirder than the Star Wars Holiday Special.
Bluesky only released their Saved Posts feature about three months ago, but I’m such a link packrat that there’s plenty there to fill a multilink post for 2025. I hope you find some interesting things in here!
@thinkygames gave us a talk by Patrick Traynor, creator of the mindtwisting puzzle game Patrick’s Parabox, and how that game was programmed. Hey, I kind of know him!
videogameesoterica.bsky.social notes that a fan translation of SEGAGAGA, one of the last official Dreamcast games and a weird and hilarious museum of Sega content, is nearing completion.
fluffcopter.bsky.social, on a weird interaction in Caves of Qud that I’m not sure if they’re kidding about or not. They “poured warm static on my dog, it turned into a dromad trader that comes with guards and items. They are all my dog, the whole trade party and merchandise. I convinced my dog to sell me my dog for free while my dog, my dog, my dog and my dog were standing guard.”
And, most recently, almondsquirrel.bsky.social reminds us that Disney Solitaire, a game with dark patterns, real money transactions and lootboxes, is PEGI rated 3+, while Balatro has none of that, but is rated 18+ because of its nebulous Poker theming.
This is one of the rare times where I won’t embed the video myself, because the blog Old Vintage Computing Research presented it as a link to their readers, and the video itself is unlisted on Youtube, so it won’t turn up in searches or through discovery features. So I hope I can help spread the word about this wonderful find.
Here is their post, and here is the video (1 hour 33 minutes). It’s a link to the Computer History Museum’s symposium on the occasion of the 25th anniversary of the Commodore 64, and has Steve Wozniak (creator of the Apple II), William Lowe (“father” of the IBM PC), Adam Chowaniec (Vice President of World Product Development at Commdore) and Jack Tramiel (founder of Commodore and key to the success of the Commodore 64).
Since this talk was given, three of the four have passed away, leaving only Steve Wozniak, probably by virtue of his youth when he invented the Apple. Please enjoy!
“Zelda Day” is a random thing over at Metafilter. One day long ago, on December 26th, there was a day in which three Legend-Of-Zelda-themed posts were made in one day. Since then I’ve commemorated the event by making another Legend of Zelda post on the same day each following year.
Here is this year’s post, but you don’t have to follow it because I’ve included the links in this post too.
They’re all videos this year. These first links are to videos by Skawo:
I think I mentioned this one before, but again, in Ocarina of Time, if you go back the way you came during the event in Kakariko Village, the world will become a glitchy mess (7 minutes):
Capsyst Animations made three fake commercials for early Zelda games, in the style of the evocative illustrations from the manual. There’s the original Zelda, Zelda II and Link to the Past (all 1 minute long):
The Amiga has hardware sprites, but they’re fairly limited. Most programmers prefer to use its powerful blitter hardware to simulate sprites, drawing them to screen memory much more rapidly than non-blitter hardware can. For more information, I refer you to the video.
That’s it for today, but there be something more substantial tomorrow….
Slowly making headway against a year’s worth of accumulated links. Please enjoy whatever takes your interest.
1. Sega’s One-Sided History, from The History of How We Play, about the tensions between Sega’s Japanese and American management.
2. From Mugen Gaming, working on a translation of Japanese TTRPG Sword World, with a crowdfunding campaign to begin in 2026. Included here because Sword World is soaked in video game influences. It really is a case of back-and-forth around the world: Wizardry and Ultima inspired Dragon Quest, Dragon Quest inspired other JRPGs, and then those JRPGs influenced Sword World. And to go with it, a nearly-complete fan translation of a Super Famicom Sword World game.
4. At Retroevolve, Mandy Odoerfer describes the charm of bootleg Pokemon games, games like 2003 Pocket Monster Carbuncle and Pokemon Vietnamese Crystal.
Image from the article, up on Retroevolve
5. The Splatterhouse Homepage, an oldschool webshrine, is still updating, and has a new page on the recent dumping of an unreleased sequel to Splatterhouse Wanpaku Graffiti, called Splatterworld, although I notice that one of its downloads is actually dated to 1993. Hmm, curious!
