RGME: That'd take too long in this video to explain. Let me know if you'd like a video on-- Me: YES Absolutely I'd love a video on how Pac Man cabinets were upgraded to Ms. Pac Man, I didn't even know they were upgraded, I just thought new ones were manufactured?
In the early 80's, upgrading cabinets became the new flavor because arcade owners wanted larger margins of profit and it was impractical in a lot of ways to keep producing more cabinets (not just the cost of the cabinet, but the freight charges to ship them overseas as well). This first involved PCB swaps and cabinet art swaps, but later evolved to motherboards and cartridges to change games, much like a home console (famously both with Neo Geo). This was more obvious in Japan, where arcades remained relevant through the 21st century, and where "candy" cabinets became the norm, which were made from plastic molds and had swappable panels for controls and art displays for marquees and instructions.
Would you like a video how old tech got updated, possibly involving hardware interactions, as well as more assembly listings? Man, we subbed here for this.
Ms Pac-Man was sort of an unlicensed ROM hack blessed to be official by both Bally/Midway and Namco. This was also the case with Pac-Man Plus as well. The practice wasn't just limited to Namco. Most famously, Donkey Kong was created as a way to convert unwanted/unsold cabinets of Radar Scope into a game that would sell. (And boy did it SELL.) In turn, there were kits to turn Donkey Kong into Donkey Kong Jr, Donkey Kong Jr to Popeye, Popeye to Mario Bros, etc.
A lot of arcade games back then were replaced and updated with retrofit kits, especially games like this that were very similar (and thus the arcade owner probably wouldn't care about having both active at the same time), but sometimes even just total replacements with other games.
On the thing about the R register, you also have to remember that Ms. Pac-Man is essentially a glorified ROM Hack, and the act of reverse-engineering the hardware (or the work of someone else who did so and documented it) probably brought things to light that official developers weren't told about or told to avoid since it was never intended to be used so upfront. It honestly reminds me of the very funny way Argonaut pitched themselves to Nintendo: By breaking the original Game Boy's internal copy protection to load a custom bootscreen (the boot screen was the crux of the copy protection, and it might be cool to see a video about this some time) and still function normally and then, with brassiest of balls or greatest of hubris, showing it to Nintendo execs at a trade show to demonstrate their inside out knowledge of the hardware.
To be fair, the copy protection of the Original Game Boy was super easy to bypass so the flex was more in the bootscreen than the copy protection bypass.
@@Toonrick12 True, because this was back when the standard strategy was to make it a trademark issue. Then Sega v Accolade happened and since showing the trademarked logo was required for the game to function, it was deemed that it was not trademark infringement to force it to display in order to circumvent the copy protection and that using a trademark functionally as a security lock is the holder's problem, not the person displaying it get their shit to work.
@@ClassicTVMan1981X I cannot find evidence that was the case. What I kind find evidence of was Falcon's Crazy Kong, while originally sanctioned, was exported outside of Japan against the agreement and Nintendo was pissed and terminated said agreement. Falcon decided that won't stop them and made a version of Donkey Kong Jr. based on Crazy Kong.
14:44 "They could even go through walls if they were programmed to" You can actually see this in a lot of bootleg hacks, where the creators forgot to change the fruit paths, so they still act as if they're in the original mazes.
Short answer is the character and program ROMs were replaced, and a daughter card that tied into the CPU socket added additional program ROMs for added capability. A primitive scrambling scheme using PALs that were supposed to be unreadable unscrambled the code that was scrambled on the daughter card ROMS. The only problem is that the CPU on the daughter card could be desoldered, and the code could be read out using a fluke 9100a or equivalent tool. Thus it only thwarted those who didn't have access to those tools. The unscrambled code could be arranged on a stack of roms soldered into a sandwich on top of the original program roms (reprogrammed with MS Pac code), and the chip select of the top stack of roms (if memory serves) could be tied into previously unused address locations, thus removing the need for the daughter card or the desoldering and socketing of the original CPU. Later variants evolved from that which were tidier, and many an unscrupulous arcade vendor performed these mods to avoid having to buy a new machine.
No, Retro Game Mechanics Explained, despite being a subscriber to your channel for years so I could learn about exactly these sorts of things, I have zero desire to learn about how Ms. Pac-Man cabinets were upgraded. I don't know how anyone could possibly come to the conclusion that I, an enjoyer of deep-dive technical explanations on all things retro game related, could ever be even remotely interested in hearing about how Ms. Pac-Man cabinets were upgraded. Frankly, it completely defies all logical explanation how you could every believe that I, a complete video game nerd who loves exactly this type of content, could EVER, in a MILLION YEARS, want to hear about how Ms. Pac-Man cabinets were upgraded. Gosh.
I hate how in Z80 syntax, so many instructions are boiled down to just "LD" like, it makes sense, but also it makes the code a lot harder to understand (at least in my opinion)
"let me know if you'd like a video on-" Literally whatever you're selling, I'm buying. I want it all, teach me everything about obscure assembly-coded stuff.
The round 256 kill screen error in Ms. Pac-Man is almost the same as in Pac-Man. That is, if you can make it through the other stages past 100 that have errors all their own (in particular the 130s-150s rounds); in those cases, the glitch results due to an incorrect condition being tested in the jump-to commands (the N, or negative, flag being tested rather than the proper C, or carry, flag).
Fun fact, it's the exact same kind of error that results in NES Tetris's glitched colors (wrong flag being tested resulting in a wrong answer a little past 128)
I would absolutely love an in-depth series about Ms. Pac-Man's patches and also comparing with the prototype footage and documentation we have of Crazy Otto and other builds. Maybe even a Pac-Man Plus bonus video!
Am I the only one who remembers a version of PAC-Man that had wildly different maze layouts? Like, some of them had areas that were more open than just straight corridors.
Could be a bootleg, could be a clone, but honestly I wouldn't be surprised if there were some official variation of Pac-Man (like Pac & Pal or whatever) that did that.
Ooh cool! I was born decades after most of the games he talks about lol, it’s only luck that I grew up with an arcade cabinet and that companies loved porting things to modern consoles at the time It is awkward being technically older than a game but just being too young to have ever played it though. The GameCube was around when I was a kid but I couldn’t really understand video games by the time it was replaced with the Wii lol
I'm not a programmer and don't really want to be, but your videos always make me want to learn to program old consoles exclusively. They're always so interesting and informative, and I look forward to every one!
I gotta thank this channel for my Pac-Knowledge Used some of it to set the high score on a Ms. Pac-Man machine at an event I went to (34400 points, which probably isn't a lot, but it is to me!!), even explained some of the mechanics to a friend I made there, all thanks to your videos ^^ Although the machine was modified, you started with 5 lives and NO chance of getting 1UPs, which was... offputting, but I pulled through I saw the first 2 cutscenes before losing everything to Sue 2 levels after
"Fun" fact: Ms. Pac Man is very unpopular with Namco themselves because of legal reasons. While everything else in the franchise is wholly owned by Bandai Namco, Ms. Pac (both the character and the game) are joint-owned by a company now known as AtGames, who get royalties. This usually isn't a problem, Pac Man World used Ms. Pac Man without any red tape, but re-releasing the Ms. Pac Man game is very tricky, and in the 2010s Namco have decided to just replace her with other female characters
"How exactly a Pac-Man arcade cabinet was upgraded into a Ms. Pac-Man cabinet, back in the day" Oh no... Let me guess, PROMs, masking the bits that need to be changed, and only being able to set bits to 0 to change existing code?
Thank you for this video, and especially thank you for explaining how the ghosts determine which route is the "shortest" to reach its target tile. I've been working on developing a Pac-man styled game, and I was really wondering how that was determined when I was developing that logic myself. A linear value seems like quite a logical way to do it! I wound up implementing A* pathfinding and calculating which tile would have the shortest possible route to their desired target. I tried using a linear check like was done here, but I had ghosts that kept getting caught in a loop in one of my mazes. Designing a Pac-Man maze is surprisingly harder than one might think!
I honestly didn't even remember that the fruits you could get were randomized. I guess that's why score attacking Ms. Pac-Man is less prevalent compared to its older brother (or I guess husband in this case). In a lot of cases, adding some elements of randomness made Ms. Pac-Man a better game since you couldn't just use the same route over and over, but it's a different story when you can literally just get a lower score through no fault of your own and it baffles me on why they made that decision.
Great video! Your Pac-Man Ghost AI video really helped me better understand the original game and get better at it, so it has always frustrated me that there's not as much documentation on this stuff for the sequels. I've always heard Ms. Pac-Man added more random elements, but could never actually find what those random elements are, so this video is very much appreciated. Will you consider doing videos on the other Pac-Man sequels like Jr. Pac-Man, or maybe even Super Pac-Man and Pac & Pal? The ghosts in Jr. Pac-Man always felt more aggressive to me, so I'm curious of how they work, as well as the "fruit" paths in that game.
An interesting thing to note is that since the fruit paths are stored as a series of directions, they sre independent of the maze tile layout, and in old hacks that change the mazes like Ms. Pac-Man Plus, the fruit paths are unchanged and thus they move through the walls
Love it. I had just been wondering the last couple days or so when the next RGME video would drop. Looks like today's my lucky day! And boy do I remember spending tons of quarters in the arcade playing Ms. Pacman as a kid.
Thank you for the great video. It's somehow satisfying how I can understand the ASM code now. Messing with Pokémon ACE (similar CPU in the game boy) takes a toll on you.
This has answered questions I've had for decades about the ghost behavior in Ms. Pac-Man, and also explains (despite never specifically mentioning it!) why the Namco Museum ports of Ms. Pac-Man on PS1 and N64 felt so off: they reintroduced the scatter phases after the first one, and also made it so all four ghosts went back to the same corners as in Pac-Man (all the time, in all four mazes). I'd love to see a video on the cabinet upgrades, also it would be great if you could delve into Jr. Pac-Man at some point. I'm curious if its shift to big mazes with no tunnels, but still with wandering bonus fruit, required further changes to any of this code.
I love your videos. I can't apply anything from them in any practical way but after watching them for years, I feel like I can follow assembly more competently
I'd personally love to know what's going on with the startup screen in Pac-Man, how it flashes a bunch of tiles and palettes erratically for some reason.
Lots of arcade games do stuff like that on startup. Part of it is testing the RAM, and may also be verifying the integrity of the ROMs to make sure they are genuine. Then it shows a grid for a brief time, that is also used in service mode to confirm the monitor is adjusted properly.
I have to mention, in the original pacman arcade game there are 2 S tunnels maze above the ghost cage and for some odd reason the ghosts can’t go up when they are below S tunnels (Until they turn blue) they can only go down when they are above the tunnels!
6:20 All of that, yes please. Ms. Pac-Man was my and my mothers favorite game when we were playing the Sega Genesis port. Maybe a followup someday about the differences between ports?
Is there a kill screen for Super Pac-Man and Pac & Pal? I checked the RAM in a hex editor and watched how the levels work in Super Pac-Man and the stuff seemed to loop but I found a post from 2010 in a forum called Classic Arcade Gaming which says that the game has at least 65,536 levels, with said level apparently having glitches.
This is EXCELLENT and I'm going to update my recent Pac-Man feature at my blog to link to this video. It probably won't be worth a lot (click-through are rare even on my most read stuff) but seriously you did a fantastic job.
Now I’m curious what glitches are in Ms. Pac-Man and how and why they differ from the original. I’ve read online before it has its own kill screen, and I’m curious about why it occurs.
The Ms. Pac kill screen occurs because of faulty code in charge of setting which tiles should make ghosts move more slowly, used for the tunnels in the early levels. These slow tiles are only meant to be created on levels 1 and 2. The code in charge of checking if the level is less than 3 looks at the wrong flag and jumps if the level count is less than 3 OR greater than 128. Similar to the Pac-Man kill screen, the routine in charge of editing the map to add this "slow bit" is expecting the level count to be 1 or 2 and, when it isn't, jumps to various areas of memory and starts writing over bytes it isn't supposed to. The effects are not the same every time, but a manner of gameplay glitches, strange visual effects, and potential crashes can occur, up until level 142 when memory becomes too corrupted and the game resets.
If you do a video on how Pac-Man machines where turned into Ms Pac-Man machines, could you also go over why Namco is/has erased Ms Pac-Man for existence in the last decade? (It's because of AtGames.)
Considering that the programmers at GenComp never had access to the original source code, and analysis of the disassembly of the code was primitive, my guess is some of the weirdness was a combination of a lack of understanding the complete code, and the timeframe that it needed to be released before the heat of Pac Man ebbed away. Pure speculation on my part of course.
I wonder if this means you would tackle the random elements in Jr. Pac-Man as well. As that game hasn't really gotten a good documentation yet. I sure would be interested in seeing that.
The problem is Bandai Namco DOES have all the rights to Ms Pac-Man. But they're forced to give money to a company they HATE for multiple other reasons when they use THEIR OWNED IP.
I found a strange bug in Sonic 3 where in the blue Special Stage with the narrow corridors (may require debug mode to access), the game will freeze for about 3 seconds after touching two specific blue spheres in the stage. Could you please explain why this happens? Thank you for the time and effort you put in for us!
I have more information now, so I'll elaborate: the Special Stage mentioned previously is Special Stage 8, which is unused and requires using debug mode to access. To activate debug mode, press up twice, then down twice, then up four times during the animation that transitions to the title screen. Lag will cause the game to drop your inputs rather frequently, so it is rather difficult to successfully enter this code (it took me about six dozen tries). I also discovered that, on occasion, these two spheres do not lock up the game, and also encountered a situation where two other spheres did this instead. I also found a peculiar situation where the game will crash upon loading some stages after reaching the first checkpoint in Icecap Zone and then returning to the debug menu by pressing A while paused. I am using an official Sega emulator for the XBOX 360, on a disc known as "Sonic's Ultimate Genesis Collection".
There's actually multiple kill screens in this game, the upside down level is just one of them. Would love to see a video elaborating on all of them tbh.
You know you've watched too many RGME videos (or is well versed in Assembly) when you see a thing that uses 2 bits and you bet it will be packed in bytes in a table to save ROM space.
Maybe I missed something, but if the R register is tied to the number of instructions executed, and a frame is always a fixed length, surely roughly the same number of instructions would execute between each read of R since it happens on a regular cadence each frame - and therefore the generated numbers would be consistent, at least in the more significant bits?
The R register is tied to the number of machine cycles. Different instructions take different numbers of cycles, and even the same instruction doesn't always take the same number - for example conditional jumps take a different number of cycles depending on whether the condition is true or not. Due to varying positions of sprites, varying scores (for example how many digit carries are needed to display the decimal equivalent), varying user inputs etc. using R appears more random than you might think.
PLEASE make more videos on ms pacman!!!!!1! also, can you talk about jr pacman? it is also a great game. Not as iconic, but it's another improvement to the original
how does the fruit glitch work when the game is in speed-up mode. since the fruit comes out after eating dot 70 and 170 respectively, when moving fast, it is possible to eat the 170th dot while the fruit is on screen
I allways hated how Clyde was renamed in ms Pac-Man I get that it was ither limitations or reusing assets But for me I allways saw Clyde and sue as different characters Sue would be the purple one and Clyde would stay his original orange At least the old cartoon got this right Do better namco
Although the code also uses lots of other Z80 exclusive features like relative jumps and the index registers. It seems unlikely they'd have used those if they wanted to maintain backwards compatibility with the Intel 8080.
Pretzels are also my favorite fruit
big mood
So are keys
Haha🤣
@@thetechsavvy01 Hey, ya gotta get your iron somehow.
as for me my favorite fruit is the bell
RGME: That'd take too long in this video to explain. Let me know if you'd like a video on--
Me: YES
Absolutely I'd love a video on how Pac Man cabinets were upgraded to Ms. Pac Man, I didn't even know they were upgraded, I just thought new ones were manufactured?
In the early 80's, upgrading cabinets became the new flavor because arcade owners wanted larger margins of profit and it was impractical in a lot of ways to keep producing more cabinets (not just the cost of the cabinet, but the freight charges to ship them overseas as well). This first involved PCB swaps and cabinet art swaps, but later evolved to motherboards and cartridges to change games, much like a home console (famously both with Neo Geo).
This was more obvious in Japan, where arcades remained relevant through the 21st century, and where "candy" cabinets became the norm, which were made from plastic molds and had swappable panels for controls and art displays for marquees and instructions.
Would you like a video how old tech got updated, possibly involving hardware interactions, as well as more assembly listings? Man, we subbed here for this.
Ms Pac-Man was sort of an unlicensed ROM hack blessed to be official by both Bally/Midway and Namco. This was also the case with Pac-Man Plus as well.
The practice wasn't just limited to Namco. Most famously, Donkey Kong was created as a way to convert unwanted/unsold cabinets of Radar Scope into a game that would sell. (And boy did it SELL.) In turn, there were kits to turn Donkey Kong into Donkey Kong Jr, Donkey Kong Jr to Popeye, Popeye to Mario Bros, etc.
A lot of arcade games back then were replaced and updated with retrofit kits, especially games like this that were very similar (and thus the arcade owner probably wouldn't care about having both active at the same time), but sometimes even just total replacements with other games.
licenced rom hack
On the thing about the R register, you also have to remember that Ms. Pac-Man is essentially a glorified ROM Hack, and the act of reverse-engineering the hardware (or the work of someone else who did so and documented it) probably brought things to light that official developers weren't told about or told to avoid since it was never intended to be used so upfront. It honestly reminds me of the very funny way Argonaut pitched themselves to Nintendo: By breaking the original Game Boy's internal copy protection to load a custom bootscreen (the boot screen was the crux of the copy protection, and it might be cool to see a video about this some time) and still function normally and then, with brassiest of balls or greatest of hubris, showing it to Nintendo execs at a trade show to demonstrate their inside out knowledge of the hardware.
To be fair, the copy protection of the Original Game Boy was super easy to bypass so the flex was more in the bootscreen than the copy protection bypass.
@@Toonrick12 True, because this was back when the standard strategy was to make it a trademark issue. Then Sega v Accolade happened and since showing the trademarked logo was required for the game to function, it was deemed that it was not trademark infringement to force it to display in order to circumvent the copy protection and that using a trademark functionally as a security lock is the holder's problem, not the person displaying it get their shit to work.
Same thing with Donkey Kong, Jr. as it too was a glorified ROM hack, of none other than its predecessor. That also triggered a lawsuit.
@@ClassicTVMan1981X I cannot find evidence that was the case. What I kind find evidence of was Falcon's Crazy Kong, while originally sanctioned, was exported outside of Japan against the agreement and Nintendo was pissed and terminated said agreement. Falcon decided that won't stop them and made a version of Donkey Kong Jr. based on Crazy Kong.
14:44 "They could even go through walls if they were programmed to"
You can actually see this in a lot of bootleg hacks, where the creators forgot to change the fruit paths, so they still act as if they're in the original mazes.
I’m interested in seeing how the arcade cabinets were upgraded!
Short answer is the character and program ROMs were replaced, and a daughter card that tied into the CPU socket added additional program ROMs for added capability. A primitive scrambling scheme using PALs that were supposed to be unreadable unscrambled the code that was scrambled on the daughter card ROMS. The only problem is that the CPU on the daughter card could be desoldered, and the code could be read out using a fluke 9100a or equivalent tool. Thus it only thwarted those who didn't have access to those tools. The unscrambled code could be arranged on a stack of roms soldered into a sandwich on top of the original program roms (reprogrammed with MS Pac code), and the chip select of the top stack of roms (if memory serves) could be tied into previously unused address locations, thus removing the need for the daughter card or the desoldering and socketing of the original CPU. Later variants evolved from that which were tidier, and many an unscrupulous arcade vendor performed these mods to avoid having to buy a new machine.
No, Retro Game Mechanics Explained, despite being a subscriber to your channel for years so I could learn about exactly these sorts of things, I have zero desire to learn about how Ms. Pac-Man cabinets were upgraded. I don't know how anyone could possibly come to the conclusion that I, an enjoyer of deep-dive technical explanations on all things retro game related, could ever be even remotely interested in hearing about how Ms. Pac-Man cabinets were upgraded. Frankly, it completely defies all logical explanation how you could every believe that I, a complete video game nerd who loves exactly this type of content, could EVER, in a MILLION YEARS, want to hear about how Ms. Pac-Man cabinets were upgraded. Gosh.
(This is a joke btw. I guess people didn't pick up on it, even though I made it as over-the-top as possible.)
still can't get over margarine? :P
"And from viewers like you, thank you"
PBS Kids Nostalgia: *hits harder than a neutron star*
Me about to pull a Dwight Schrute moment
@@thetechsavvy01 "Nostalgia is truly one of the great human weaknesses... second only to the neck"?
Oh yeaa
Gotta love a random neutron star reference!
using 6502 assembly syntax on Z80 assembly code is kinda cursed but also based.
If it works it works ;)
I hate how in Z80 syntax, so many instructions are boiled down to just "LD"
like, it makes sense, but also it makes the code a lot harder to understand (at least in my opinion)
"let me know if you'd like a video on-" Literally whatever you're selling, I'm buying. I want it all, teach me everything about obscure assembly-coded stuff.
Amen brother.
can we have a video on minecraft pls
@@christophercampbell6884 not really a retro video game
@@joemkdd yes it is
6:23 YES please make a video on that!!! I love this sort of deep dives into explanations of retro games' quirks and bugs
As soon as I saw the upload, I said “Yes. I love these videos. I’m watching this immediately.”
Not even joking, not even trying to overrate.
As you should
The round 256 kill screen error in Ms. Pac-Man is almost the same as in Pac-Man. That is, if you can make it through the other stages past 100 that have errors all their own (in particular the 130s-150s rounds); in those cases, the glitch results due to an incorrect condition being tested in the jump-to commands (the N, or negative, flag being tested rather than the proper C, or carry, flag).
Fun fact, it's the exact same kind of error that results in NES Tetris's glitched colors (wrong flag being tested resulting in a wrong answer a little past 128)
Why do they test for flags instead of just checking if the value in the X register is less than or equal to the value in the Y register DIRECTLY?
I would absolutely love an in-depth series about Ms. Pac-Man's patches and also comparing with the prototype footage and documentation we have of Crazy Otto and other builds. Maybe even a Pac-Man Plus bonus video!
Am I the only one who remembers a version of PAC-Man that had wildly different maze layouts? Like, some of them had areas that were more open than just straight corridors.
Maybe you're remembering some bootleg, clone, or fan game.
There were so many clones, I remember what you're talking about, but couldn't tell you which iteration
could you possibly be thinking of "worlds biggest pac man"?
Possibly the Hangly-Man bootleg board.
Could be a bootleg, could be a clone, but honestly I wouldn't be surprised if there were some official variation of Pac-Man (like Pac & Pal or whatever) that did that.
This channel actually helps me understand old games since I wasn’t old enough to play most of them
Ooh cool! I was born decades after most of the games he talks about lol, it’s only luck that I grew up with an arcade cabinet and that companies loved porting things to modern consoles at the time
It is awkward being technically older than a game but just being too young to have ever played it though. The GameCube was around when I was a kid but I couldn’t really understand video games by the time it was replaced with the Wii lol
I'm not a programmer and don't really want to be, but your videos always make me want to learn to program old consoles exclusively. They're always so interesting and informative, and I look forward to every one!
Literally! I know I’ve looked up “how hard is it to learn assembly code” after binging these videos lmao
I gotta thank this channel for my Pac-Knowledge
Used some of it to set the high score on a Ms. Pac-Man machine at an event I went to (34400 points, which probably isn't a lot, but it is to me!!), even explained some of the mechanics to a friend I made there, all thanks to your videos ^^
Although the machine was modified, you started with 5 lives and NO chance of getting 1UPs, which was... offputting, but I pulled through I saw the first 2 cutscenes before losing everything to Sue 2 levels after
1:31 a very nice amount of changed bytes
"Fun" fact: Ms. Pac Man is very unpopular with Namco themselves because of legal reasons. While everything else in the franchise is wholly owned by Bandai Namco, Ms. Pac (both the character and the game) are joint-owned by a company now known as AtGames, who get royalties. This usually isn't a problem, Pac Man World used Ms. Pac Man without any red tape, but re-releasing the Ms. Pac Man game is very tricky, and in the 2010s Namco have decided to just replace her with other female characters
It's mostly because Namco has a big grunge with AtGames for using their name on a low quality product and being beaten in court because of it.
"How exactly a Pac-Man arcade cabinet was upgraded into a Ms. Pac-Man cabinet, back in the day"
Oh no... Let me guess, PROMs, masking the bits that need to be changed, and only being able to set bits to 0 to change existing code?
Love this stuff! Please do go into more details about the ms Pacman upgrade. And "it's assembly, so it's quite a lot" had me laugh out loud 😂.
Thank you for this video, and especially thank you for explaining how the ghosts determine which route is the "shortest" to reach its target tile.
I've been working on developing a Pac-man styled game, and I was really wondering how that was determined when I was developing that logic myself. A linear value seems like quite a logical way to do it! I wound up implementing A* pathfinding and calculating which tile would have the shortest possible route to their desired target. I tried using a linear check like was done here, but I had ghosts that kept getting caught in a loop in one of my mazes.
Designing a Pac-Man maze is surprisingly harder than one might think!
I honestly didn't even remember that the fruits you could get were randomized. I guess that's why score attacking Ms. Pac-Man is less prevalent compared to its older brother (or I guess husband in this case). In a lot of cases, adding some elements of randomness made Ms. Pac-Man a better game since you couldn't just use the same route over and over, but it's a different story when you can literally just get a lower score through no fault of your own and it baffles me on why they made that decision.
I just had mini-pretzels, so i can confirm they are a good fruit.
You upgrade a Pac-Man cabinet into a Ms. Pac-Man cabinet with HRT
Hahahahaha
a cabinet using a CRT screen getting HRT
@@abraham3673Hormone-Ray Tube
Lol
PFFT
Great video! Your Pac-Man Ghost AI video really helped me better understand the original game and get better at it, so it has always frustrated me that there's not as much documentation on this stuff for the sequels. I've always heard Ms. Pac-Man added more random elements, but could never actually find what those random elements are, so this video is very much appreciated.
Will you consider doing videos on the other Pac-Man sequels like Jr. Pac-Man, or maybe even Super Pac-Man and Pac & Pal? The ghosts in Jr. Pac-Man always felt more aggressive to me, so I'm curious of how they work, as well as the "fruit" paths in that game.
I think this channel should also go over the physics of Retro Styled Sonic the Hedgehog Games like Sonic 1 and Sonic Mania.
An interesting thing to note is that since the fruit paths are stored as a series of directions, they sre independent of the maze tile layout, and in old hacks that change the mazes like Ms. Pac-Man Plus, the fruit paths are unchanged and thus they move through the walls
Love it. I had just been wondering the last couple days or so when the next RGME video would drop. Looks like today's my lucky day! And boy do I remember spending tons of quarters in the arcade playing Ms. Pacman as a kid.
I always want to see more RGME content, regardless of what it's about
I would love to see a video on how the pac-men were upgraded, along with whatever other miscellaneous changes were made to most machines
001 name = cabinet upgrades
010 print "interest flag = true"
020 goto line 010
run
Thank you for the great video.
It's somehow satisfying how I can understand the ASM code now. Messing with Pokémon ACE (similar CPU in the game boy) takes a toll on you.
I'd be very interested in learning how the Pacman cabinets were upgraded to Ms. Pacman cabinets!
This has answered questions I've had for decades about the ghost behavior in Ms. Pac-Man, and also explains (despite never specifically mentioning it!) why the Namco Museum ports of Ms. Pac-Man on PS1 and N64 felt so off: they reintroduced the scatter phases after the first one, and also made it so all four ghosts went back to the same corners as in Pac-Man (all the time, in all four mazes).
I'd love to see a video on the cabinet upgrades, also it would be great if you could delve into Jr. Pac-Man at some point. I'm curious if its shift to big mazes with no tunnels, but still with wandering bonus fruit, required further changes to any of this code.
Hey I remember you, You’re the one who explains about how Ghosts RNG work! Great video you did back there
I love your videos. I can't apply anything from them in any practical way but after watching them for years, I feel like I can follow assembly more competently
I’d watch a ten hour video of you explaining upgrades to arcade cabinets
i understood all of this. because i am so good at programming. anyways nice vid! always like the stripped-back visuals, simple but effective.
pls say this sent
I'd personally love to know what's going on with the startup screen in Pac-Man, how it flashes a bunch of tiles and palettes erratically for some reason.
Lots of arcade games do stuff like that on startup. Part of it is testing the RAM, and may also be verifying the integrity of the ROMs to make sure they are genuine. Then it shows a grid for a brief time, that is also used in service mode to confirm the monitor is adjusted properly.
I have to mention, in the original pacman arcade game there are 2 S tunnels maze above the ghost cage and for some odd reason the ghosts can’t go up when they are below S tunnels (Until they turn blue) they can only go down when they are above the tunnels!
6:20 All of that, yes please. Ms. Pac-Man was my and my mothers favorite game when we were playing the Sega Genesis port. Maybe a followup someday about the differences between ports?
Yes! We are indeed interested about how the Arcade cabinet got upgraded from Pac-Man to miss Pac-Man
The "fruit index" sounds like a derogatory term for the Kinsey scale.
This sure is a thought process.
honestly, I wouldn't be bothered by it, it sounds funny
"hey shawty what's your fruit index"
Some fruits are more likely to appear
Kinsey ray(-)ped infants ad documented it in detail, there is no derogatory "term" for anything to do with that, pure evil
Reusing cabinets is always interesting.
The follow up video on how pacman cabinets were upgraded to ms pacman cabinets would be awesome! i hope there's enough demand for you to make it
Is there a kill screen for Super Pac-Man and Pac & Pal? I checked the RAM in a hex editor and watched how the levels work in Super Pac-Man and the stuff seemed to loop but I found a post from 2010 in a forum called Classic Arcade Gaming which says that the game has at least 65,536 levels, with said level apparently having glitches.
Definitely would like that follow up tangent on how the machines where upgraded
I'm so glad you're tackling this!
Wow. I always figured Ms. Pacman was just a reskin and nothing more. I think everybody did.
This is EXCELLENT and I'm going to update my recent Pac-Man feature at my blog to link to this video. It probably won't be worth a lot (click-through are rare even on my most read stuff) but seriously you did a fantastic job.
Oh dang, I never knew Ms Pac Man was an upgrade! She's just like me
"And the pretzel - my favorite fruit..." hahaha pls.
i'd say "yes, i'm interested in that" but hell, i'll watch anything you make
6:16 A video covering the actual conversion process would be really interesting.
Yes, would love a follow-up upgrade vid!
Now I’m curious what glitches are in Ms. Pac-Man and how and why they differ from the original. I’ve read online before it has its own kill screen, and I’m curious about why it occurs.
The Ms. Pac kill screen occurs because of faulty code in charge of setting which tiles should make ghosts move more slowly, used for the tunnels in the early levels. These slow tiles are only meant to be created on levels 1 and 2. The code in charge of checking if the level is less than 3 looks at the wrong flag and jumps if the level count is less than 3 OR greater than 128. Similar to the Pac-Man kill screen, the routine in charge of editing the map to add this "slow bit" is expecting the level count to be 1 or 2 and, when it isn't, jumps to various areas of memory and starts writing over bytes it isn't supposed to. The effects are not the same every time, but a manner of gameplay glitches, strange visual effects, and potential crashes can occur, up until level 142 when memory becomes too corrupted and the game resets.
Yummy packer info numba 3
Yummers
If you do a video on how Pac-Man machines where turned into Ms Pac-Man machines, could you also go over why Namco is/has erased Ms Pac-Man for existence in the last decade? (It's because of AtGames.)
I would love your take on classical ROM hacking, and how Crazy Otto / Ms. Pac-Man was built from Pac.
I’d definitely like that follow up video!
8:04 Feels like maybe they threw that in in order to make the long tube at the bottom slightly more of the death trap it was clearly intended to be?
Omg this is amazing im so happy u posted another video!!!
Wait, a video on SPECIFICALLY MS PACMAN!?
BOOYAH!
Definitely want more Ms. Pac man content!!!
I'd love a video on upgrading a pacman cabinet!
Would love to see a follow-up video
I love these videos!
Considering that the programmers at GenComp never had access to the original source code, and analysis of the disassembly of the code was primitive, my guess is some of the weirdness was a combination of a lack of understanding the complete code, and the timeframe that it needed to be released before the heat of Pac Man ebbed away. Pure speculation on my part of course.
Always a great day when you upload, thanks!
I wonder if this means you would tackle the random elements in Jr. Pac-Man as well. As that game hasn't really gotten a good documentation yet. I sure would be interested in seeing that.
I'd be interested in that follow up!
Ms. Pac-Man was created out of Crazy Otto; which was a mod-kit for Pac-Man.
I seriously hope Bandai Namco gets the rights to _Ms. Pac-Man_ back so we can see it on modern hardware without piracy.
The problem is Bandai Namco DOES have all the rights to Ms Pac-Man. But they're forced to give money to a company they HATE for multiple other reasons when they use THEIR OWNED IP.
Super Pac Man? Iirc, it was bundled with Ms. Pac Man on the original Game Boy.
I found a strange bug in Sonic 3 where in the blue Special Stage with the narrow corridors (may require debug mode to access), the game will freeze for about 3 seconds after touching two specific blue spheres in the stage. Could you please explain why this happens? Thank you for the time and effort you put in for us!
I have more information now, so I'll elaborate: the Special Stage mentioned previously is Special Stage 8, which is unused and requires using debug mode to access. To activate debug mode, press up twice, then down twice, then up four times during the animation that transitions to the title screen. Lag will cause the game to drop your inputs rather frequently, so it is rather difficult to successfully enter this code (it took me about six dozen tries). I also discovered that, on occasion, these two spheres do not lock up the game, and also encountered a situation where two other spheres did this instead. I also found a peculiar situation where the game will crash upon loading some stages after reaching the first checkpoint in Icecap Zone and then returning to the debug menu by pressing A while paused. I am using an official Sega emulator for the XBOX 360, on a disc known as "Sonic's Ultimate Genesis Collection".
you should make a video about how pac man is canonically divorced
You know once this is video hits hard. We're likely gonna ask for why the kill screen is an upside down stage
There's actually multiple kill screens in this game, the upside down level is just one of them. Would love to see a video elaborating on all of them tbh.
@@letcreate123 Wait there's more than one kill screen for Ms. Pac Man!? This is awesome I love watching how glitches even happen!
I vaguely recall Namco Museum Vol 3 mislabeling the pretzel as a cookie
I love the little PBS reference in your new intro :-)
YEAH NEW RGME VID
So Ms. Pac-Man relates to Pac-Man as
Super Mario Bros 2 (aka The Lost Levels) relates to Super Mario Bros -
I get it.
OF COURSE we'd like a video on upgrading Pac-Man! You didn't even need to ask
You know you've watched too many RGME videos (or is well versed in Assembly) when you see a thing that uses 2 bits and you bet it will be packed in bytes in a table to save ROM space.
1:32 Finally... Expert nerds that talk about nerdy stuff can say a meme number.
Love these vids! Thank you!
Can you do random element's for Jr. Pac-Man?
Maybe I missed something, but if the R register is tied to the number of instructions executed, and a frame is always a fixed length, surely roughly the same number of instructions would execute between each read of R since it happens on a regular cadence each frame - and therefore the generated numbers would be consistent, at least in the more significant bits?
The R register is tied to the number of machine cycles. Different instructions take different numbers of cycles, and even the same instruction doesn't always take the same number - for example conditional jumps take a different number of cycles depending on whether the condition is true or not. Due to varying positions of sprites, varying scores (for example how many digit carries are needed to display the decimal equivalent), varying user inputs etc. using R appears more random than you might think.
@@gwishart That makes sense! Thank you
yay another pac-man vid
the phrase "fruit index" amuses me way too much
Yes, please make the extra video.
I wonder why they didnt just use pairs of staring and ending coordinates and then used the normal target movement system for the fruits?
Pretzels are, as we say in my country, a noble fruit
PLEASE make more videos on ms pacman!!!!!1!
also, can you talk about jr pacman? it is also a great game. Not as iconic, but it's another improvement to the original
id love to know the upgrade process.
how does the fruit glitch work when the game is in speed-up mode. since the fruit comes out after eating dot 70 and 170 respectively, when moving fast, it is possible to eat the 170th dot while the fruit is on screen
can you explain the ms pacman killscreen
I allways hated how Clyde was renamed in ms Pac-Man
I get that it was ither limitations or reusing assets
But for me I allways saw Clyde and sue as different characters
Sue would be the purple one and Clyde would stay his original orange
At least the old cartoon got this right
Do better namco
Maybe the writers of the original Pac-Man wanted it to also run on an 8080. The R-Register only has been included with the Z80.
Although the code also uses lots of other Z80 exclusive features like relative jumps and the index registers. It seems unlikely they'd have used those if they wanted to maintain backwards compatibility with the Intel 8080.
Very interested in a follow up