We’ve linked videos in this series many times before, but it’s wuite a doozy this time. Final Fantasy is known to have a number of combat bugs. Critical Hit chances are determined by the index of the weapon in the weapon table, not the stat in that table; weapon special properties just don’t work, regardless of what the Nintendo Power Strategy Guide says; and more.

This isn’t just an explication of those bugs though, it goes through all of how basic (non-magic) combat works in the game, explaining the value of all the stats. That’s one of the things about RPGs: you’re told items are “+4 better,” but often those values don’t match up to what they’d mean in D&D, where a plus is usually either a one-point increase in damage, a 5% improvement on odds for something, or both. Final Fantasy’s attack roll turns out to be a 1-in-200 die, so, a mere +1 is negligible to attack odds.

They probably didn’t elaborate on what these numbers mean in the manual because, at the time, Square and Nintendo were keen to get players hooked on Final Fantasy and other JRPGs, and nothing would dissuade them from picking up the game than to be confronted with battle formulae in the manual. Looks too much like school work! But they could have at least mentioned something about relative chances?

If you really want to know what the numbers mean, the video is there waiting for you. You can just let your eyes glaze over during the math if you want. I won’t tell the teacher!

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The chief difference between normal, sequential programming and game programming is that most video games have to make a framerate target, and have to split their processes between frames. Lots of little things are usually happening concurrently, and you can’t rely on normal program flow to keep track of things. Instead, each of those little processes has to remember what it’s doing between frames, and that memory takes the form of state machines, reminders of what each routine is in the middle of doing.

Drawing it out with circles like in this video I think makes it seem a bit more complicated than it actually is, but it does require a different way of thinking about your code than you may be used to in other programming disciplines.

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Here’s the video. If you enjoy this sort of thing, we’d probably get along very well in person!

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Video Games 101, a side channel of a Let’s Play channel, covers much the same ground as U Can Beat Video Games. Some of the specific games are different. VG101 is a bit more about entertainment than the specifics of beating games and the strategy involved. Professor Brigands has three “TA” characters that assist him: Scary Gary (covering bosses), Blaze (a surfer who goes over the available items in each game) and Fluff the cat puppet, the most fun of the group, who explains game trivia and history.

I’m just putting it off still further at this point. Here is the intro video to the channel, followed by the list of every walkthrough VG101 has posted to date.

NES

Nintendo

Donkey Kong(10m)
Donkey Kong Jr.(11m)
Super Mario Bros.(39m)
Super Mario 3 (Full Walkthrough)(2h58m)
Super Mario Bros 3 (with warps)(21m)

The Legend of Zelda
First Quest(1h28m)
Second Quest(2h2m)

Zelda II(2h13m)
Kirby’s Adventure(2h2m)
Metroid(1h32m)
Kid Icarus(1h27m)
Punch-Out!! NES(47m)
StarTropics(2h8m)
Tetris (Strategy Guide)(23m)
Yoshi’s Cookie (Strategy Guide)(18m)
Dr. Mario (Strategy Guide)(20m)
Yoshi(14m)
Baseball(26m)
Tennis(29m)
Golf(14m)
Pro Wrestling(34m)
Ice Hockey(14m)
Volleyball(23m)
Excitebike(12m)
Pinball(26m)
RC Pro-Am(28m)
Rad Racer(31m)

Capcom

Ghosts ‘n Goblins(39m)
Mega Man(43m)
Mega Man II(1h2m)
Mega Man III(1h4m)
Mega Man IV(1h10m)
Ducktales(30m)
Duck Tales 2(34m)
Darkwing Duck(43m)
Chip ‘n’ Dale Rescue Rangers 2(44m)
Legendary Wings(38m)

Konami

Gradius(21m)
Castlevania(26m)
Castlevania II(1h3m)
Castlevania III(1h39m)
Contra(21m)
Super C(26m)
Teenage Mutant Ninja Turtles NES(47m)
Teenage Mutant Ninja Turtles II: The Arcade Game( 1h4m)
Teenage Mutant Ninja Turtles III(1h3m)
Metal Gear(1h29m)
Track and Field (all World Records)(15m)
The Goonies II(43m)
Top Gun(38m)
Tiny Toon Adventures(30m)
The Adventures of Bayou Billy(42m)
Blades of Steel(25m)
Sid Meier’s Pirates! NES(1h22m)

ICOM

Shadowgate(42m)
Deja Vu(47m)
Uninvited(35m)

Tecmo

Ninja Gaiden II(52m)
Ninja Gaiden III(51m)
Rygar(43m)

Sunsoft

Batman NES(30m)
Batman: Return of the Joker(25m)
Blaster Master(1h45m)

LJN

Friday the 13th(24m)
A Nightmare on Elm Street(42m)
Jaws(22m)
T&C Suft Design (18m)

RPGs and Related

Faxanadu(1h36m)
Legacy of the Wizard (Dragon Slayer IV NES)(1h16m)
Dragon Warrior (Dragon Quest NES)(1h51m)
Final Fantasy(4h)
Crystalis(2h2m)

Brawlers

Double Dragon(24m)
Double Dragon II(23m)
Double Dragon III(29m)
River City Ransom(47m)

The Guardian Legend(1h54m)
Adventures of Lolo(42m)
Adventures of Lolo 2(47m)
A Boy and His Blob(21m)
The Battle of Olympus(1h9m)
Adventure Island(1h7m)
Bubble Bobble(1h2m)
Maniac Mansion(1h1m)
Low-G-Man(41m)
Robocop(25m)
Battletoads(57m)
8 Eyes(49m)
Paperboy(18m)
Jackie Chan’s Action Kung Fu(37m)
Gremlins 2(25m)
Shatterhand(54m)
Beetlejuice(31m)
Dr. Jekyll and Mr. Hyde(56m)
Rockin’ Kats(50m)
Magician(1h19m)
Vice: Project Doom(43m)
The Three Stooges(26m)
Super Dodge Ball(21m)
King’s Quest V(1h10m)
Kick Master(39m)
Puss ‘n Boots(15m)
Home Alone 2(25m)
Burgertime (Strategy Guide)(11m)
Dr. Chaos(1h7m)
Werewolf: The Last Warrior(1h39m)
Star Trek: 25th Anniversary(1h15m)
Bart vs The Space Mutants(48m)
Bugs Bunny Birthday Blowout(50m)
Bad Dudes(24m)
The Flintstones(36m)
Total Recall(25m)
Robin Hood: Prince of Thieves(1h7m)
Ghostbusters(24m)
Back to the Future(23m)
Who Framed Roger Rabbit?(56m)
M.U.S.C.L.E.(15m)
Ninja Kid(19m)
The Legend of Dino Riki(24m)
Narc(25m)

GENESIS/MEGA DRIVE

Home Alone(56m)

SNES

Super Mario World
Part 1(44m)
Part 2(41m)
Part 3(45m)
Part 4(52m)
Ghoul School(34m)
Illusion of Gaia(7h4m)
Super Metroid(2h46m)

Super Mario RPG
Part 1(3h2m)
Part 2(3h2m)
Part 3(2h42m)
Part 4(2h41m)

Secret of Mana
Part 1(2h29m)
Part 2(1h59m)
Part 3(1h59m)
Part 4(1h48m)

The Legend of Zelda: A Link to the Past(3h57m)
Super Punch-Out!! SNES(34m)
Mega Man X(1h25m)
Mega Man X2(1h29m)
Final Fight(43m)
Sunset Riders(34m)

NINTENDO 64

Star Fox 64
Easy Route(47m)
Medium Route(43m)
Hard Route(51m)

Super Mario 64
Part 1(1h13m)
Part 2(59m)
Part 3(1h7m)
Part 4(51m)

Goldeneye 007(1h52m)

MISCELLANEOUS

Oregon Trail(26m)
Quest for Glory(1h4m)
Myst(1h29m)
Alley Cat(17m)

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Even I began to drift off a few times through this one. It is exhaustive, and exhausting, but it’s very thorough.

I won’t even try to explicate it all in text, but here’s a few interesting tidbits of information:

• Super Mario Bros., the original, built its levels on the fly. As you scrolled forward, the engine read the upcoming data and constructed it up ahead, off screen, in real time, always keeping ahead of the screen’s edge. This is why you can’t scroll backwards, the list is designed to be read going left to right. SMB2 instead includes extra RAM in the cartridge and uses it as a memory buffer to hold the entire current room, up to 10 screens in size. When you enter an area, the game takes a moment to construct the map in that buffer, and copies it to the PPU’s video RAM as you scroll around.
• Instead of with stored as-is tilemaps, SMB2’s, as well as basically all of Nintendo’s scrolling games at the time, are constructed, made out of tile objects with different locations and parameters attached to them. This saves a substantial amount of ROM space, and functions as a kind of bespoke data compression.
• The rooms are built screen by screen, although it’s possible for some items to extend horizontally or vertically outside of its home screen.
• The format makes it seem like vertical rooms were designed first, and horizontal scrolling areas were then added to that functionality.
• There are weird special cases everywhere in the building code! Some objects only work on certain levels, or serve different purposes in different worlds.
• Birdo’s color, and behavior, depends on its initial spawning X tile position. If it’s 10 she’ll be a pink Birdo; if it’s 11 she’ll be red, and all other values mean a grey Birdo will be generated.
• On the enemy list, entity numbers 92-127 are the same as the entities numbered 64 less than them, but with the property that, when they are despawned, the level ends! This property is used for world-ending bosses, but any entity in that range will end the level when it leaves play, even Mushrooms if one such existed.
• Crawgrip, the boss to World 5, was added to Super Mario Bros. 2 during its conversion from Doki Doki Panic. The decorative rock background objects in its boss arena are especially hacky, like they were hastily added.
• The stars in the sky in the night levels have a bug in their generation that prevents any from appearing on the first screen of their areas. They also aren’t placed specifically, but using a pseudo-random generation algorithm that always uses the same seed, so they’ll always appear in the same places in the sky.

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Both were recovered by the website Games That Weren’t. Here’s their page for Sensible Soccer, and here’s the page on Populous. Both pages feature rom images that can be downloaded and played in an emulator.

Sensible Soccer’s claim to fame is a mixture of statistical depth and arcade-like gameplay that might bring players to mind of Tecmo Bowl. Wikipedia’s page on it, in fact, suggests that a Tecmo arcade game may have been an inspiration. Populous did see console releases for both the Mega Drive/Genesis and the SNES. The SNES version included content from an expansion pack, and has a number of additional terrains, as well as over a thousand levels to play. How did it do it? It created its maps procedural, natch, and you got to skip a number of levels depending on how well you did on the last map.

Looking at the tiny view onto the game world the NES version allows, it isn’t surprising to me that it never saw release. Compare to a screen from the Amiga version (screenshot from Wikipedia):

As can be seen, even the Amiga version only shows a small portion of the playfield, but it still gives you more to see than the NES version, although I think the number of visible tiles, 64, is in fact the same. The NES’s color limitations are also a problem, and what you don’t see in the screenshot is that moving the display around isn’t instant. The NES can’t change many background tiles in a single frame without blanking the screen, so what Populous does, on that platform, is do an animated vertical wipe when the display scrolls. It takes about half a second to change views, so when moving tile by tile across a large area the delays accumulate and slow down the game. That may also be why it doesn’t use larger tiles, it’d compound the delay in scrolling the viewport.

Despite that though, it’s great to see the game finally greet the world after so long, and even though it’s rumored to have a couple of bugs, Sensible Soccer looks like it might be a keeper.

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The problem: you’ve made something you think is pretty darn great. Maybe you’d like to distribute it for people to use easily without having to set up an emulator, like it were some kind of native application? Maybe you’d even want to sell what you’ve made, and participate in the equatable exchange of goods and services you’ve heard people talk about in huddled whispers, but never thought you might engage with yourself?

The solution: Use EASTPIXEL‘s NESbag or GBCbag!

The indicated programmacalities* take a supplied rom image (even if said image never came from actual ROM chips) and erect a software box around it. Then you can distribute that package to other people, and they can double-click it to run it, just like it were a standard desktop executable, and it’s even rumored to be Steam Deck compatible.

A pre-built version is supplied for Windows. For Linux you’ll probably have to compile some code, if just because there’s so many distributions. For Mac, you’ll have to compile it yourself as well, but the process is rumored to be pretty simple.

* Feel free to use this word in your own conversations! People will love it!

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On Romhack Thursdays, we bring you interesting finds from the world of game modifications.

Didja ever finish a satisfying round of Tetris, and then, basking in the glow of your high score, stop to wonder to yourself: why four?

Why did Alexey Pajitnov, revered creator of the game, decide to use tetrominoes, the possible combinations of four squares attached to each other, as the basis of his game, and not some other number? Two is obviously too simple, and three is also pretty easy. Four is the smallest number that makes for an interesting game, so that was probably why. But can Tetris work with larger pieces? Could it work with, say, pentominoes, five-square pieces?

Well, why not try it for yourself, with today’s romhack: Zohassadar’s Pentris.

Pentris is built from Bullet-Proof Software’s NES version of Tetris (which is different from the Famicom version). It’s a BPS file, but there’s multiple utilities that can apply those, for Windows, Mac and Linux. For Win, Flips works well. Linux users may be able to find Flips in their distro’s repositories. For Mac, try Multipatch. The big advantage of BPS is that it contains CRCs of the original patch file to ensure that it’s working on its expected file, a continual problem with working with roms. As for where to get an original of NES Tetris from, you’re on your own.

Notably, Pentris is quite a bit harder than Tetris. It’s not kaizo hard though, it seems like it may be possible to have a lengthy game, but it’ll probably take you longer to develop a good intuition for what moves are good ones than it did for Tetris.

There are more possible pentominos than there are tetrominoes, so the long-piece is less common, and pentrises require five lines of setup instead of four, making them much harder to make than tetrises. In my several test games, I never managed to make even one. But mere survival is more difficult too. Pentris’ bin is 14 blocks wide instead of 10, which is more room to make mistakes. And some of its pieces are much more unwieldly than the worst of Tetris. Tetris has Z and S, but Pentris has Texas:

Pentris doesn’t appear to monkey with NES Tetris’ piece generation. The NES game picks pieces almost entirely randomly, rerolling just once if two of the same piece in a row is selected. More recent versions use “bag” systems that guarantee that you get all the possible pieces in a reasonable amount of time, but neither NES Tetris nor Pentris hold your hand like that. If you’re depending on a 1×5 piece but the RNG doesn’t feel like giving you one, you’re left to lump it.

In addition to that Texas abomination, there are also “long L” and “long J” pieces, and identical versions but with the extra square moved one space up the bar part, a piece that’s like half of a picture frame, and, invading from Rampart, the dreaded U and Plus shapes. Where you choose to place them, as they relentlessly fall, is up to you.

If you focus on survival you can advance a few levels. A good beginner’s score of Pentris is about 5,000 points. My highest so far is about 6,800. I don’t know how many points a pentris is worth, but if it scales like the multi-line clear points from Tetris did it’s probably very valuable.

I feel like I should mention there is at least one other game called Pentris around, a web game that doesn’t seem to be maintained too well. It has some of the same ideas behind it, but it also has other sized shapes too, including single blocks. I don’t know much about it, but I do know it is substantially a different game from the romhack Pentris.

Pentris (romhacking.net, somehow, still around!)

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Due to this, there’s homebrew NES software that’s made to use the SNES mouse, and even emulators that will convert your PC’s mouse into simulated SNES mouse signals, which will be fed into the emulated NES and the software running thereon. (It isn’t all buttons, but it sends the displacement as a binary number.)

The video comes to us from the account of CutterCross, who’s making CrossPaint, an NES art program that uses the SNES mouse. A demo can be gotten from itch.io.

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(A warning if you play this one and are sensitive to flashing images, there is a violently flashing effect right before the bosses that won’t treat you very well, I’m afraid.)

Her article is ostensibly the subject of this post, and I’ll try not to repeat points that she makes. Stinger holds a place in my heart, if not a prominent one then still one at all, after all it has blood to pump. It was the first NES game I ever beat! If memory holds correctly the second one was The Legend of Zelda, which is kind of fitting: Stinger is easier than it looks, so it builds confidence, while Zelda is harder. (It took me months, mostly from being stuck finding the entrance to Level 7 in the Second Quest.)

In Japan, Moero Twinbee was not only a Famicom Disk System game but one that supported up to three players (P3 used a controller plugged into the expansion port). The US ROM version only allows two players, which realistically probably makes for a better game anyway. Even with a single player, once you get the five-way shot powerup it’s easy to fill the screen with so many bullets that you don’t actually see many enemies.

Kimimi recounts much of what makes Moero Twinbee/Stinger different both from other shoot-em-ups and from other Twinbee games: the bell powerup system that’s Twinbee’s trademark, and the side-scrolling stages that are unique in its series. The side-view levels are particularly interesting, not only because the game both begins and ends with one, but because it completely changes the gameplay in a couple of significant ways.

You see Twinbee is a variation upon the theme of Namco’s Xevious, complete with its bomb button to attack ground-based installations, and that depends on its overhead perspective. But Moero’s side-scrolling levels ditch it completely: in those, and only those, the Bees fire arcing bombs along with their main shots, with the same button, and it’s those that can hit ground targets at the bottom of the screen. The bomb button is repurposed to fire hearts, a different special weapon that only works on bells.

Oh those bells, them and all their tintinnabulations. If you’ve never played Twinbee, but have played one of the Cotton games, you already know how they work. Some targets (usually clouds in the Twinbee games) release colored powerup objects. They rapidly fall down towards the bottom of the screen, but they can be kept in play by shooting them, bouncing them up. As you shoot them, every few hits it changes color, and different colored bells award different powerups. I like powerup systems like this and the Gradius system, and consider them superior to the standard icon-based setup from Salamander and practically every other shmup. You get to decide which powerups you want, possibly to activate them just when you need them, but you still have to use skill and judgement to get the ones you need when you need them, whereas games with set powerup locations force you to choose between what you have and what you’re given.

Hearts get fired from your ship upward in the side-view stages. It’s a lot harder to hit bells when they’re falling vertically past your horizontally-moving shots, instead of when both bells and bullets move vertically, and the hearts are meant to make up for that, but they’re so useless that it’s a much better strategy, in practice, to just get up close and pepper them with shots up close. The best powerup is the force field, which grants you several free hits (and doesn’t summon the wave of shield-weakening egg enemies from the first game), but it’s also the one that takes the most bell hits to earn. Another thing to aim for is just collecting the default yellow bells, which award no powerups, but every one you collect without letting a bell fall off-screen rapidly earns you more points, up to 10,000 points each after collecting just four yellow bell in a row. It only requires 100,000 points for an extra life, then additionals every 200,000, up to about 900,000 or so. 10,000 points per bell is such a huge bonus that, once you’re good with your powerup state, gigantic scores aren’t too hard to reach, and there’s three extra lives right in the first stage anyway.

The Twinbee games have always had interesting bosses, which helps to distract from the fact that, up to Detana! (the fourth Twinbee game, and the second in the arcade) most of the other targets are just popcorn enemies. When you just get started playing Moero Twinbee, it’s not uncommon to rule through the game with 3- or 5-way shot, the best powerups you can get from the ground targets, then get demolished by a boss you don’t yet know how to beat and then, reduced to single shots, either have your game end right there, or barely get in the last few shots against the boss and then get inundated by the popcorn enemies in the next level.

The first bell powerup in the sequence, blue, is Speed-Up, and unlike Gradius where too much speed will kill you extra dead, it’s mostly beneficial in Stinger, because you can’t crash into the terrain and you’ll probably have a force field anyway. With at least 3-Way shot, a couple of Speedups and the force field, the only real danger is the harder bosses and your force field running out. The blue-white flashing force field bells don’t appear if you already have one, and you’ll probably run out in the middle of Stage 6, where the game finally rolls up its sleeves and gets to punching. If you can then somehow build up another blue-white bell (it takes exactly 25 hits on a bell to make one), you have a chance at finishing the game. Like many Konami games at the time, Stinger continues indefinitely, loop after loop, and it gets slightly harder each time.

Konami made three Twinbee games for the NES; the first was a remake of the arcade original; this was the second; and the third, Poko Poko Daimaou, I think is inferior. They form a trilogy; then for the fourth game, Detana! Twinbee, it was rebooted, keeping the Bees’ creator Professor Cinnamon but bequeathing them to his grandnephew, grandson and granddaughter Light, Mint and Pastel, whose popularity would soon outstrip the originals, especially Pastel who became quite a phenomenon. Detana was followed up by Pop’n Twinbee and Rainbow Bell Adventures on Super Famicom, Twinbee Yahho in arcades, and a handful of anime OAVs.

Kimimi on Moero Twinbee – Hardcore Gaming 101 on Moero Twinbee and Stinger

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Now there’s a heavily-modified version of GB Studio, called BB Studio, that produces NES roms in a similar manner! It’s made by Michel Iwaniec, and can be gotten from Github here. It’s recommended that you be familiar with GB Studio first, and to read the list of caveats on the page. Particularly, the NES supports fewer sprites per scanline than the Gameboy hardware does, and runs at a slower clock speed. BB Studio is also “early alpha software,” meaning, it might or might not work well for you at the moment.

While we’re on the topic I should also mention NES Maker, which isn’t free, but it also isn’t “early alpha software,” and at $36 isn’t expensive either, and is custom-built for generating runnable NES games.

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The lawsuit was really about Nintendo trying to stamp out the game rental business in the US, which they were largely successful at in Japan. Cartridge manufacturers were genuinely frightened of rentals cutting into their profits, and resorted to measures like increasing the difficulty of games in the US market to prevent players from completing games on a single rental and losing out on sales. Howard Lincoln of Nintendo of America called game rental “…nothing less than commercial rape.” While the Software Publishers Alliance (SPA) managed to get legislation passed that outlawed the rental of computer software, video games were separately defined and rental allowed to continue.

They sought out any legal means they could to make game rentals less attractive. Manuals were one way to do this. While rental stores couldn’t easily copy the games in order rent our more copies, it was fairly easy to make a good-enough reproduction of a manual using a copy machine. Nintendo sued Blockbuster over the practice, which was eventually settled out of court, but Blockbuster sent a letter to the four stores they had who were accused of the practice telling them to stop.

If you were around at that time, you might remember that for a time rented games would sometimes come with their own small makeshift manuals, sometimes taking the form of an adhesive sheet stuck to the plastic case. It seems these were a small industry that saw the lack of durable instructions provided with games as a little economic niche they could take advantage of.

The lack of manuals supplied with games may have been the reason for a weird quirk on one of Nintendo’s games. The game Startropics has one infamous place where the game asks the player to enter a code from materials supplied with the game. There was a sheet of paper that came with boxed retail copies of the game, an Infocom-style “feelie,” that if soaked in water revealed a code (747) that had to be entered into the game at one point to continue. The code wasn’t revealed anywhere in the game, so players without the sheet couldn’t progress.

Interestingly, while the WiiU Virtual Console version of Startropics has an online manual that reveals the code, the Switch online version has no manual, and leaves players stranded there unless they look up the answer online.

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Human-readable numbers are tracked by computers in a number of different ways. Nowadays we basically just do a printf or some version of it, but on a 1 megahertz platform, optimization really matters. It’s easy to think of computers as being impossibly fast, but in truth speed only ever counts relative to the efficiency of the algorithm you use. Computers are fast, but they aren’t all that fast.

One of the big tradeoffs in processor design is, fewer complex instructions that do a lot but take a lot of cycles, and processor complexity, to execute, or many simple instructions, each doing little and being relatively simple, and not needing a complex processor design to implement.

The 6502 microprocessor generally follows the latter design philosophy. It made some important tradeoffs to keep costs down. For example, it doesn’t have hardware that can multiply arbitrary numbers together. It relies on the programmer, or else a library author, to use the instructions given to code their own multiplication algorithm, if they need one. The result is going to be slower, probably, that if the chip had the circuits to do this automatically in silicon, but it reduced the cost of the chip, basically allowing more to be made, or else increasing the profits for the manufacturer.

Personally I’m a fan of just storing the score as a series of digits that match up to their positions in the character set. Gain 1,000 points? Just bump the 1000s-place up by one, and if it goes past 9, subtract 10 and bump the 10,000s place. That’s a tried-and-true system that many games use, and works well if all you ever have to do is add numbers. Comparing values, like for detecting extra life award levels, make things slightly more complex, but not by much. There’s sometimes other factors involved though, and that may explain why Super Mario Bros. uses different systems for its counters, as explained by NESHacker.

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I won’t keep you waiting for the link: here it is. And here is my grossly simplified summary, intended to inspire you to go to the original article, if you have the time, and get all the deets.

Guardic Gaiden, known in the US as The Guardian Legend, uses a weird trick to put its status bar at the bottom of the screen, instead of, as usually seen in an UNROM game, at the top. To create a fixed status window requires stopping whatever the processor is doing at a very precise time while the display is being drawn to the TV, and then changing some PPU registers to display the status.

More complex and versatile mappers, like the MMC family, have the ability to trigger interrupts at specific screen lines, but Guardic Gaiden/Guardian Legend doesn’t use an MMC. It doesn’t even have a raster line counter, so the game simply doesn’t know where on screen the raster beam is drawing.

There are still lots of games on the system that have status windows, even with MMC chips. The PPU has a built-in feature called Sprite 0 Hit, where the chip can signal when Sprite 0 (of the system’s 64 sprites) is being drawn on top of non-transparent background data. So what older games commonly do is put Sprite 0 in an unobtrusive place at the bottom of the status window at the top of the screen. When the Sprite 0 Hit register indicates a collision, the code knows it’s time to set up the PPU to display the main portion of the game screen.

There is a really big problem with this setup, though. Sprite 0 Hit doesn’t trigger an interrupt. It doesn’t stop the code to let it switch the graphics. It’s not even proper to say it “sends a signal.” It’s up to the code to check if Sprite 0 Hit has been triggered. If it has, then it’s time to set the scroll register to the right place, and maybe switch to the proper background tileset, and do whatever else needs to happen, and the code can then be off to run essential game logic, the actual game part of the game.

If it hasn’t… then, the code has to check again, and immediately. And if it hasn’t triggered then, to do it again. It has to literally check as quickly as it can, because if it delays in its check, the game screen might not get set up at the right moment, which will be perceptible as the bar straying down one extra line that one frame. Not the end of the world, but it looks glitchy. And this code will be running every frame, so if it strays down once, it might do it again, which is a more perceptible glitchiness.

Sprite 0 is set to trigger its hit at the top of the screen, because the code won’t have to spin its wheels checking the hit over and over. It wastes time, but not that much. This is why UNROM games put their status lines, with the score, timer, health bar and life counters, at the top of the screen.

Well, The Guardian Legend is an UNROM game, and maybe because creators Compile wanted to show off, they decided they’d put the bar at the bottom of the screen. And yet, their game doesn’t waste most of each frame just in maintaining the status bar.

How? And what does that have to do with the Twin Famicom? For that I’m going to direct you to Nicole Express’ blog post. May you find it as fascinating as I did!

Nicole Express: Is the Twin Famicom Flawed? The Case of Guardic Gaiden

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It’s only about nine minutes long so you can guess that it doesn’t go into deep detail. Essentially the NES is split into two parts, the CPU and its memory, and the PPU graphics chip and its own memory. A lot of classic consoles and microcomputers had to take special measures to support their display, which often ended up being the most complex part of the unit. Think about it: you have what amounts to a deluxe broadcast character generator right there in a box on your desk, shelf or floor, with lots of extra bells and whistles besides. (In fact, home computers were often used to generate current events channels for local cable companies, and an Amiga was essentially the basis for the old Prevue Guide channel.) It’s like a tiny special-purpose, single-receiver TV station just for your own use.

Graphics hardware is extremely timing sensitive. It has to generate the signal for your TV to display according to standardized picture generation requirements, so special requirements are often necessary. In the Commodore 64, for instance, the VIC-II graphics chip has the power to actually put the 6510 CPU to sleep, so it can have unrestricted access to the computer’s memory, without fear of bus conflicts, when it’s needed. This reduces the overall speed of the processor by a bit, and it’s why C64s turn off the screen when loading programs from cassette tape, in order to keep the CPU timing consistent relative to the data being streamed in off the tape.

The NES gets around this by giving the PPU RAM and address bus for its own exclusive use, and to put stuff in it the CPU has to use the PPU as an intermediary. And what’s more the NES exposes both the CPU and PPU’s address busses through the cartridge connector (which is why it’s got so many pins), allowing carts to supply dedicated ROM and RAM to both chips.

Even though it’s just a high-level overview, I found it a worthwhile use of those nine minutes, and you may very well enjoy it too.

NES Hardware Explained (from NESHacker, on Youtube, 9 minutes)

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Sundry Sunday is our weekly feature of fun gaming culture finds and videos, from across the years and even decades.

So despite the fact that you likely already know all of this, I still feel like I have to explain it all for people who might not have soaked their brains in US popular culture, yet still care enough about video games that you’re reading Set Side B. Let’s get it out of the way as quickly as feasible.

Premiering December 17, 1989, The Simpsons has been on the air for approaching 35 years. We in the United States are going to have to come to terms with the fact that it’ll probably be the reigning television fact of our lives. When it began, the NES was still the hot game system, and that was eons ago.

Premiering in the 7th season, during the time when most people still agreed The Simpsons was the best show on television, was the episode 22 Short Films About Springfield, in which the writers created a loosely-connected sequence of miscellaneous stories about the many side characters in The Simpsons. One of those stories was “Seymour and the Superintendent,” where Bart’s principal hosts his boss Superintendent Chalmers to a home-cooked meal, but due to a sequence of comical events serves him Krusty Burgers instead, covers it up in a variety of unlikely lies, and nearly burns down his house. Colloquially this has become known as “Steamed Hams,” after one of the lies Principal Skinner tells.

In 2017, a popular meme went around the internet in which people remade, remixes, or otherwise re-did that story, alone of all of them in the episode, the season, and among the long long run of the show.

In fact, those memes are still being made, and this post’s subject is one of them. It’s a video simulating what a Steamed Hams game would have been like if it were made in the style of the Bart vs the Space Mutants and Bart vs The World games on the NES. It was made by Penney Pixels, it’s four minutes long, and it’s here, and here:

There is an actual game version of the Steamed Hams, of which a playthrough is recorded here, and can be downloaded here. There’s another version of Steamed Hams too, and it can be played on GameJolt here. Both of those are adventure games.

I thought Steamed Hams had come up here before, but a quick search didn’t find anything, so I’ll just leave it at this. I’m sure in the next 35 years there will be hundreds more game versions of Steamed Hams. Maybe after all that time, I’ll be able to bring myself to mention it here again.

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We link to such a variety of things here. Sometimes we post light videos where someone has Kirby do funny things. Sometimes we show explainers that explain how to do arithmetic on old processors. I presume that you’ll take from these what you want, and leave the rest to the crazy people, by definition the people who are not you. I understand.

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Running .NET on the NES (Youtube, 43 minutes)

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Episode 1 (15 minutes):

Episode 2 (17 minutes):

That removed BCD feature. Why? The video notes that the circuits are right there within the chip, but have been disabled by having five necessary traces severed. The video notes that the 6502’s BCD functionality was actually patented by MOS, and asks, was the feature disabled because of patent issues? Was Ricoh trying to avoid paying royalties?

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The talk is intended for a technical audience… literally. When the speaker asks who in the audience has coded in assembly before, practically everyone raises their hands. It’s recognized that we at Set Side B veer wildly between the most surface-level populist material and in-depth treatments for those with gigantic capacities for technical discussion and the attention span of a Galapagos Giant Tortoise. We like to think this is charming, and will listen eagerly if you tell us that you agree.

Anyway, here is that talk. I already mentioned that it’s 53 minutes. If that’s too long, there’s a speed-up function on Youtube. If that’s too technical, well, I don’t know how to help there. Maybe a read through pagetable.com’s documentation on the 6502. Oops! I’ve made it worse, haven’t I. Well, if you like, you might console yourself that the 6502 is really a simple processor to learn to code in. I’ve done it myself! There’s no memory management, there’s only three general-purpose registers, the stack is fixed in place, and all opcodes are one byte. It’s so simple that an extremely motivated child could learn it. Guess how I know?

27c3: Reverse Engineering the MOS 6502 CPU (Youtube, 53 minutes)

Here’s a description of the talk from the conference web site.

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Snake’s Revenge is the forgotten Metal Gear game, an NES sequel made without Hideo Kojima input, to the NES port of Metal Gear that he also had nothing to do with. It has a reputation for being terrible, but that’s really unmerited. As Kurt Kalata notes, while it has its flaws, is ignored by later Metal Gear games, and it has a story based on the manual scenario for Metal Gear written by Konami’s crazy American writing staff*, it’s technically proficient and has good music.

You can, and should read it for yourself, here.

* The American manual for NES Life Force says that the evil planet-eating monster Zelos was the proud progeny of “Ma and Pa Deltoid.” In the description of Dracula’s Heart in the manual for Castlevania II, it warns: “Careful! The heart attacks.” These were not means isolated occurrences from Konami’s US staff.

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Sundry Sunday is our weekly feature of fun gaming culture finds and videos, from across the years and even decades.

While there are examples of excellent music from the classic era of arcades (Frogger comes immediately to mind), I don’t think there is much that can equal that of Gyruss’ arrangement of Bach’s Tocatta and Fugue in D Minor. Here it is, isolated from the rest of the game’s soundtrack, from Youtube uploader StyleK226 (1 1/2 minues):

Wikipedia tells us that the arcade arrangement is reminiscent of a version of the song from the British band Sky, titled just “Toccata” (4 1/2 minutes):

If you only know Gyruss from the NES port, you might be surprised that it’s an almost entirely different arrangement from the arcade version! Maybe it was changed because of the similarity to Sky’s version. Some people prefer that one, it’s got a bit more variety, although I think the arcade’s is a bit better. Judge for yourself (3 minutes):

The Toccata is only used for the intro and the first warp on each planet, which is a bit of a shame, the rest of the music isn’t bad, but it’s not Bach. In Japan, Gyruss was a Famicom Disk System game. The FDS had extra sound hardware, and the result is an upgraded version of the NES soundtrack (14 minutes in all):

There’s been a number of fan versions of the Gyruss soundtrack, although most of them seem to be inspired by the NES port rather than the arcade original. Here’s a metal medley of that particular musical mutation (3 minutes):

As commenter @Fordi says, “What I love is that Intro / Stage 1 is a genre cover (metal) of a game’s adaptation (Gyruss) of a genre cover (Sky – Toccata) of classical music (Toccata and Fugue in Dm).”

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In the meantime, ten games from 1990 are in this episode. They are:

Puss ‘n’ Boots: Pero’s Great Adventure – Technically a retread of a previously-covered Japanese game, this version has substantial differences so Dr. Sparkle decided to cover its U.S. version separately. A very easy game until the last stage where it jumps in difficulty, and then the final boss is absurdly hard. Dr. S expresses confusion why a game made to be so easy that it’s obviously intended for young children would become nearly impossible right at the last second. Personally, I suspect it was done because NES game publishers were terrified of the game rental market.

Wit’s: A Japan-only release, this is basically a de-luxe version of Snake, where your enemies have special abilities that you have to account for. Suprisingly, it’s an arcade port!

Captain Tsubasa Vol. II: Super Striker: A weird RPG take on Soccer, published by Tecmo and based on a manga and anime series. Instead of controlling a player or players completely in real time, the action pauses frequently and asks you what to do. The main screen is mostly animations down on the soccer field. It’s a unique take on soccer, but it’s not the only one: this is the second game to play like this on the Famicom. The Captain Tsubasa game series continues even today: the most recent releases, Dr. Sparkle tells us, are on PS4 and Nintendo Switch, although I don’t know if they take the menu-based RPG approach.

Jyuouki: This is simply a licensed Famicom port of Sega’s Altered Beast, and a pretty bad one at that.

Mahjong G-Men: Nichibutsu Mahjong III: Yet another Mahjong game, although with some interesting features, if you’re into Mahjong. That’s not Mahjong Solitaire, a.k.a. Shanghai, the Activision (and formerly PLATO) computer game where you remove tiles in matching pairs from a tableaux, but the Chinese Rummy-like game using tiles instead of cards. It also has a weird Tetris-like subgame involving Mahjong tiles.

The Pennant League: Home Run Nighter ’90: Yet another Famicom baseball game.

Dr. Mario: The classic Nintendo puzzle game! I always thought it was a bit inferior to Tetris, but then most games are, and that didn’t stop me from playing a ton of it long ago.

Pictionary: Based on the board game, and coming from infamous American NES publisher LJN. Dr. Sparkle is a bit harsh on developer Software Creations, but I think this effort looks pretty well-made to me. It’s not a classic, and it’s actually not really so much Pictionary as a kind of variation on the theme, where players play mini-games to reveal parts of a drawing and then try to guess what the drawing is of. It looks much like one of Rare’s many game show and board game adaptations and creations, and in fact if it weren’t for the Software Creations credit I’d have assumed that Rare made it.

Bigfoot: From Acclaim and developed by Beam Software. It’s fairly well polished for a Beam Software title, but has some weird ideas to it, including a weird control scheme for the events that involves tapping left and right on the control pad. I think the idea has a bit of merit, but that it was probably the wrong place to use it. A Bigfoot game would mostly be bought or given to kids, who would be the absolute last demographic you should expect to master a non-standard control scheme. I’m not one of those people who thinks making a game that goes about its play differently than most other games is always a terrible idea (see: most of what I’ve ever written about roguelikes), and I can kind of see why they did it, trying to make a race game that’s more than just holding to the right. It probably could have used a bit more iteration though.

Snake Rattle ‘n’ Roll: A game from Rare that they actually put a lot of effort into, and it shows. And some people really like it, it’s definitely got a cult following. Dr. S isn’t part of it, due to the difficulty of getting used to SRnR’s isometric style. I think what happened was, they had these routines laying around that they used in implementing NES Marble Madness, and decided to do another game that controlled in that kind of way. I think the game was poorly suited to a digital control pad; if it were controlled with an analog stick, or at least a digital control where diagonal movement is easier, I think it’s possible that some people who hate Snake Rattle ‘n’ Roll might be able to enjoy it better.

Anyway, here is the whole episode, start to finish:

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A while back the site HackADay did a teardown of the NES, going through how to take it apart and reassemble it, and going through some of the elements of its assembly. It doesn’t go into a lot of detail, but that lets it be fairly short, at only nine minutes.

NES Hardware Explained (HackADay post, Youtube video)

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Another fact about J&H: the Japanese version had two full levels that were cut from the U.S. version, which replaced them with replays of other levels. It made a bad game even worse!

Now, because of Behind The Code, you know more about the Dr. Jekyll and Mr. Hyde game than many much better NES titles. Congratulations!

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It’s 19 minutes long, and is even geekier than is usual for us, going into a disassembly of the game’s machine code in its quest to make the game marginally less awful.

As long as we’re on the topic, here’s Jeremy Parish’s NES Works episode on Dr. J & Hyde, which is also 19 minutes, and also covers the somewhat better (but not hugely so) game Amagon:

While we’re on the subject, did you know that Jekyll & Hyde has a secret ending? Both endings are shown here (4 minutes):

The “bad” ending is the normal one, and shorter, but is arguably a happier conclusion to the story. To get it, all you have to do is get to the end of Stage 6 with Jekyll. That’s all.

To get the other ending, get to Stage 6 with Jekyll, then turn into Hyde and get to the end of his version of the stage. Usually, if Hyde gets as far into his level as Jekyll has gotten into his, he’s struck by lightning and dies. But in this level he’ll be allowed to reach the end of his version of the level for some reason, where there’s a boss! Beat it, and when you return to Jekyll’s world the enemies will be gone, and he’ll be free to finish the level without harassment. However, ending events will be different….

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When you post as many Youtube videos as I do, it’s easy to form opinions about their style. That of “TheRetroDude,” as he styles himself, is interesting, it’s still hyper-edited in the way that so many Youtubers loathsomely adopt, but it’s not nearly as distracting as those. He keeps the volume down, as well as the number of swoopy objects tearing around the screen like a toddler newly introduced to Toblerone.

He has good points about how extraneous the game’s scoring system is too, although his misgivings could be laid against many other games. In Super Mario Bros, score is mostly a spacer before toppled turtles start giving extra lives. I think that score isn’t a bad addition to a game as long as it’s implemented thoughtfully, yet for too long it hasn’t been. Even in the NES days it was included to give players a short term goal to aim for, when they didn’t really need it.

What would a good scoring system look like, one that rewarded skill? Well–

• Losing a life would reset score to that at the last passed checkpoint, eliminating point pressing from lives.
• Extra lives at game end would be worth a bonus each.
• Game timers are worth a small, yet substantial, award at level end, to prioritize fast play over slow.
• Awards should be given for score, most typically extra lives, but others are possible too.
• Replaying levels, and other means of “minting points,” earning arbitrary scores, should be ruthlessly eliminated. If the player can replay levels indefinitely then think about if your game really needs a score, and if it does, don’t allow players to earn more points from replaying them without costing them the points from that last pass.

Two games that come to mind that do scores well are:

• ZANAC on the NES, being a scrolling shooter without checkpointing score is generally fair, although it is possible to warp backwards does break the no-replay rule, and
• Star Fox 64, which only adds a level’s score to the player’s total at its end. SF64 is a game obviously designed around score attacks.

Where was I? Oh! Here is that video about Mega Man’s scoring system.

Mega Man 1’s Really Weird Score System (Youtube, 9 minutes)

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Sundry Sunday is our weekly feature of fun gaming culture finds and videos, from across the years and even decades.

This week’s fun video isn’t decades old, in fact it’s from just a few days ago, from AGDQ.

The NES title Gyromite, a.k.a. Robot Gyro, is a very interesting game from a design standpoint, possibly more interesting than it is to actually play (although I think its music is very catchy). It’s never been rereleased by Nintendo, for the probable reason that it relies on the accessory R.O.B. to play.

R.O.B. was a motorized accessory that activated servos in its arms depending on light signals sent to it from the screen. No cords went from R.O.B. to the NES. It used photoreceptors in its “eyes” to detect the screen signals, which were ultimately caused by player input on the controller. A fairly roundabout means of control, honestly.

Only two official R.O.B. games were made, and Gyromite (Going by its Japanese name “Robot Gyro” according to the title screen) used the “gyro” accessory for play. A platform is placed in front of R.O.B., on which you place the controller for Player 2.

On the controller is a device that spins the “gyros,” colored weighted tops. By manipulating the arms with action on Player 1’s controller, making them swing around and opening and closing the claws at the right time, you can cause R.O.B. to lift the spinning gyros from their platform, then set them down on the NES controller’s buttons. In the game, this caused colored pillars to rise or fall according to the control signals.

While manipulating all of this, you also have to watch out for the action of the game itself. Gyromite is a simple platformer, but one without a jump button. The difficulty comes from having to essentially play two games at once, the platforming on screen and manipulating R.O.B. to position pillars in the right places in space and time.

R.O.B.’s motions are not simple to command either. It takes time for the arms to pivot between their destinations, time that must be accounted for in the on-screen action, and while the tops spin for quite a while they will eventually have to be collected and set back on their pedestals so they can be spun back up to full speed, or else they’ll topple over on the button. This doesn’t produce a failure state in the game. It’s just left to you to pick the top up yourself and put it back on its stand to be spun again. R.O.B. isn’t capable of such feats of dexterity.

There’s a lot more to say about R.O.B., and how it was mostly distributed as part of the Nintendo Entertainment System’s “Deluxe Set” in the U.S., the more expensive version that didn’t come with Super Mario Bros. Instead of that, let’s talk about how, due to the fact that R.O.B. is just a fancy-shmancy way to press controller buttons, that you can replace it entirely with some other mechanism, or indeed, even animal.

That’s what happened Wednesday at AGDQ, where Peanut Butter the Dog, with coaching from JSR_, left R.O.B. gathering dust in the closet as they played through Gyromite Game B.

They didn’t make it all the way without running out of lives, but they picked back up and kept going. And that doesn’t detract at all from Peanut Butter’s skills, or amazing doggy focus. They are intent on reading those hand signals and getting those tasty treats. So while they didn’t earn a world record, for “Dog playing Gyromite Game B,” their accomplishment is of definite note.

There are around four minutes of introductions at the start of the video, so if you want to jump right in to the run, begin here.

Gyromite by Peanut Butter the Dog & JSR_ in 26:24 – Awesome Games Done Quick 2024 (Youtube, 33 minutes)

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I’ve been looking into the various home computer ports of Pac-Man lately. One of the better ones is the one for Famicom/NES, probably because it was made in-house at Namco, which I presume because while it’s by no means perfect, it has ghost AI that much more closely matches Jamey Pittman’s definitive Pac-Man Dossier than the others. This is a bit more important than the other ports because, due to the relative familiarity (that is to say, inexpensiveness) of NES emulation at this point, Famicom Pac-Man is often put in compilations, especially in dedicated consoles, instead of the arcade game. In point of fact, the Namco Museum Archives Vol. 1 that’s available for various consoles uses the Famicom versions of all its games, not the arcade, and Pac-Man is one of the included games. To tell the difference: if the score, fruit tally and lives are to the right of the screen, instead of above and beneath it, and Pac-Man looks a little too big to fit in a maze passage, then what you have is an inferior home conversion.

How is it different? Well:

• The sound of Pac-Man eating dots is much worse, for starters, it never fails to bother me.
• More substantively, the ghosts have slightly different constants in their chase routines: it’s slightly harder to fake out the Pink ghost (Speedy/Pinky), and the Orange ghost (Pokey/Clyde) gives up the chase a little more reluctantly.
• The timing for scatter periods, relative the speeds of the ghosts, is a little off. Scatter periods are usually slightly longer.
• The speed of the game as difficulty increases is also a little off. In the arcade, the First Apple board (Level 5) marks a noticable increase in Pac-Man’s speed, but it seems to happen around the Second Orange (Level 4) on Famicom. Yes, that’s how much of arcade Pac-Man and its port that I’ve played-it could be subjective, but maybe it’s not.
• The bug that affects Pink’s and Blue’s (Bashful/Inky) AI when Pac-Man’s facing up doesn’t exist here.
• When ghosts enter Scatter mode, they don’t reverse direction. This makes the game easier (one less sudden reverse to throw you off) and harder (no obvious indication that the ghosts are scattering, and one less thing to throw them off from immediate pursuit).
• As the game advances in difficulty, in the arcade, on the 4th Key board (level 17), the ghosts won’t turn blue and vulnerable when you eat an Energizer, and instead will just reverse direction. And from the 6th Key (level 19) on, the ghosts will never turn blue again! NES Pac-Man instead gives them a very tiny bit of blue time, about a half-second’s worth. It never reaches a state where the ghosts become completely invulnerable.

And at last, the bug which I have confirmed. On the 10th Key board (Level 22), and every level thereafter, the ghosts will start out in an unusually long Scatter period. Their usual habit is to emerge from the box in the center of the screen and move to a corner of the screen, and circle there for a few seconds. Pink goes to the upper-left, Red (Shadow/Blinky) to the upper-right, Orange to the lower-left, and Blue to the lower-right. This period is called a “Scatter Mode” in the Pac-Man Dossier.

In most levels, presuming you don’t lose a life, the ghosts will enter Scatter Mode at exactly set three times: from the start, about 25-or-so seconds in, and about 30 or so seconds after that. These periods are usually five seconds long. There are some minor details I won’t get into-you can read the Dossier for those. These periods are lifesavers for intermediate Pac-Man players playing without patterns, as they are the only really safe ways to access the bottom passages of the board without getting trapped or wasting an Energizer.

Each Scatter Mode is only supposed to last five-to-seven seconds, but on Level 22 and after, all of the Scatter Modes last around 20 seconds. Here is the bug in action, demonstrated in Namco Museum Archives Vol. 1:

Why would this board be different from the others? In the arcade, the 9th Key (Level 21) is the maximum difficulty the game reaches. Any pattern that works on the 9th Key level will work for the rest of the game, all the way up to the kill screen on Level 256. It seems that, on the Famicom/NES version, after that level the game may not have data for the level to follow? But I haven’t looked at its code to know for sure. Maybe I should make that a future project.

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