This topic is for the purpose of discussing #7166: Lucky_Bacon's NES Fist of the North Star in 06:08.94

That was completely unexpected! These new finds are insane! Yes vote.

Cool find, what made you think to try that?

Cool find, what made you think to try that?

These finds were mostly found accidentally way back when i had no internet. (The one you had happen in level 6's boss, but differently, in level 2, and scroll lock bypass) I was around 9. I was just playing the game, and when i got to level 2's miniboss, i saw it spawned in the middle of the screen, instead of one of the sides. I found that wierd, but didn't care much about it, until i saw that i killed it in one hit. I didn't know much about programming back then, so i just shrugged it off. About 1 second after the fight was over, i started hearing some weird faint sound effect, and then an explosion occured, and that item spawned, which i missed the first time. Some time later, it happened again. This was around the time i started becoming a glitch hunter, and also having way too much fun with randomized Game Genie codes. This time, i remembered to collect the item, and when i did, i fell through the floor, and i was surprised to see i was in level 3. Not much i could do though, since i didn't have any computer. And even if i did, i wouldn't even know where to start. Many years later after i started playing with emulators, i started playing with tools like FCEUX's HEX memory editor, and then later on, simple ASM programming, and then, the debugger. So i started having fun breaking games with glitches, and eventually went back to this game. I was able to reliably bug out bosses like that, exploring the glitchy out-of-bounds area by bypassing the scroll-lock. And this is how i accidentally discovered skipping bosses. I tried doing that on the first boss, not miniboss, but i before spawning the boss, i just punched both enemies at the same time, for fun. And then the boss just spawned in the middle of the screen, where one of the enemies were, and appeared glitchy: It wasnt moving, and then the game just moved on to the next level. I was amazed. The reason i wait a little before spawning the boss in the movie is that if i do it while the enemies are about to explode, it will take much longer to do the transition. The value at 0x0084 increases every frame, and does the transition once it reaches FF. When an enemy finally explodes, it changes from 3B to 80, which speeds things up a lot. The number at 0x0089 seems to change randomly between two numbers, and the boss will only glitch out if that address is a certain number. I don't know very much how this works because it seems to differ every time. But if it doesn't work with one number, then just wait until it does change, if it ever does, then spawn the boss. Level 2 miniboss spawning two of these level-skip items took me by surprise when i did that glitch on it. Anyway, i plan on making a compilation of quick undiscovered(?) glitches from random videogames in one video eventually, and that game will be in there, including all the glitches in aware about. If you're curious about the scroll-lock thing, all you have to do, is reach a place where the camera stops. If you went fast enough, you might notice a few pixels showing either the next area, or a glitchy mess. Once that's done, you want to make the camera move the other way ONE pixel, or just enough to not completely hide those extra pixels, then just go back. The camera no longer has any boundaries, unless you go back to the intended location. Here's a clip of something i discovered when trying that in random places way back then: Link to video EDIT: Source video was accidentally deleted. Fixed.

I am entertained by the hero on a pogo stick.

In NES Hokuto No Ken (the previous game in the series, as this is Hokuto No Ken 2, source https://en.wikipedia.org/wiki%2FFist_of_the_North_Star_%28NES_video_game%29%23Development+%29 you can manipulate enemy projectiles to spawn behind Kenshiro and boost from them, trading health for speed. Is this possible in this version also? little bit elaborated NES Hokuto No Ken mechanic: - nearly every button on every frame changes the outcome of a projectile being spawn, the position of the projectile and the direction of the projectile - hitting a projectile boosts him if it hits Kenshiros from the back while it flies to him (looks like this happens in this version as well, those blue projectiles following you and the way they boost you forward) - a projectile is usually 1 dmg but there are other projectiles, damaging more

I look forward to you glitch compilation video.

"You are already dead." https://www.youtube.com/watch?v=po77bJk1DdI. Yes vote.

MESHUGGAH: I will need to look into that. These boosts should be useful in levels with transitions, like level 2, first floor of level 6, 7, and tight spaces from breakable blocks. Other than that, if it's just rooms that go straight to a boss, or gates in level 5, i would actually lose about 3 frames, due to the camera not scrolling during the knockback. Only the camera position matters in those cases. CoolHandMike: "You are already dead." *Bunnyhops away*

Now that you mentioned camera scrolling, I think NES Hokuto no Ken also requires it for entering doors, not just Kenshiro's position. So projectile boosting would help if you are at the right cam position but Kenshiro isn't, sacrificing 1 health for a few horizontal position advance.

Seeing how fast level 7 ended after defeating the boss, i thought i did something "special", and was hoping to see if this could be done in other levels. Instead, i see that it was just coded that way, only for that level? Don't know if this snippet helps, but thats what i understood just from these lines. I'm still a beginner at this, and debugging stuff.

B898:  A9 80     LDA #$80      ;default value to set $84 when bosses' death animation is finished
B89A:  85 84     STA $84       ;boss death frame counter, incrementing
B89C:  A5 FE     LDA $FE       ;not sure
B89E:  D0 10     BNE $B8B0     
B8A0:  A5 EE     LDA $EE       ;current level
B8A2:  29 07     AND #$07      
B8A4:  C9 03     CMP #$03      
B8A6:  90 04     BCC $B8AC     
B8A8:  C9 06     CMP #$06      ;level 7
B8AA:  D0 04     BNE $B8B0     
B8AC:  A9 C0     LDA #$C0      ;Set this value to $84
B8AE:  85 84     STA $84       ;boss death frame counter, incrementing

Not sure why they even did this. That's unfortunate.

I've just realized that you seem to be a new TASer judging by your post counts. I'm impressed by your first movie if that's the case and I see you are eager to learn. Haven't watched the whole TAS through an emulator, so now I can only say: keep up the good work! :) Here's my notes for the lines of your snippet: (the numbers became colorful because I've used this tag: [code=lua])

Language: lua
B898:  A9 80     LDA #$80      ;load the hexadecimal number 0x80 to A(ccumulator)
B89A:  85 84     STA $84       ;save A to 0x84 memory address
B89C:  A5 FE     LDA $FE       ;load the value of 0xFE memory address to A
B89E:  D0 10     BNE $B8B0   ;if the zero flag is not set, branch to the subroutine located @ B8B0. 
Looks like zero flag is set, so we stay at the current branch. 
The zero flag is the 2nd from the right of the processor status registers. 
You need to open the debugger or change your emulator settings to be able to see these values. 
Probably supported by both FCEUX and BizHawk.

B8A0:  A5 EE     LDA $EE       ;load the value of 0xEE memory address to A
B8A2:  29 07     AND #$07     ;is the result of A && 7 is true?
B8A4:  C9 03     CMP #$03     ;is the value equals with 3?
B8A6:  90 04     BCC $B8AC    ;if the clear flag is not set, branch to the subroutine located @ B8AC. 
Looks like the clear flag is set, so we stay at the current branch. 
The clear flag is the last one of the processor status registers.

B8A8:  C9 06     CMP #$06      ;is the value equals with 6?
B8AA:  D0 04     BNE $B8B0     ;same as 4th line. Zero flag not set.
B8AC:  A9 C0     LDA #$C0      ;load the hexadecimal number 0xC0 to A
B8AE:  85 84     STA $84       ;save A to 0x84

Feel free to ask any questions, I might able to answer it.

Going through both this run and the published run side by side, I noticed that some sections of movement are executed slower in this run. I put together a comparison spreadsheet showing both runs, along with some notes/advice about the specific sections. Would you mind looking into/explaining some of these?

Going through both this run and the published run side by side, I noticed that some sections of movement are executed slower in this run. I put together a comparison spreadsheet showing both runs, along with some notes/advice about the specific sections. Would you mind looking into/explaining some of these?

-This looks like bad enemy RNG, could be manipulable/avoidable? -Sprite overflow glitch saves time here, but I feel like the enemy spawns could be manipulated for a faster result? -Well I mean good job skipping two stages for sure, but I've got the same suggestion with the previous sprite overflow usage. I've tried many things to get the enemies to spawn how i want to so i wouldn't need to go left. I am not sure how enemy spawning works. At the moment, all i have that could help with that is address $0385, and that if i bring the screen too far in S2 miniboss, they wont spawn at all, unless i go back to the staircase. The limit seems to be about in the middle of the second window. I can still defenitely see improvement to be done there, if they would stop throwing things making them fall behind a lot. That address might not even be of use, and i might just be getting the wrong idea from it. S6 Postboss: Check the published run here and look at how it climbs the staircase at the end. You seem to lose time on every staircase like that in this stage. I definitely know what i did wrong with those staircases and how to fix that. I did not realize my mistake until pointed out. So does pausing change the spawn patterns? You gain a good number of frames from not having to deal with as many enemies. Definitely look more into this. Pausing only delays their spawning for a little. Doing it multiple times prevents them from spawning. This was pretty much done if i was sure there was no way to dodge their attacks, knocking me back. I'll still look into it. S6 Miniboss 3: What a weird section in both runs. I'm not sure what to make of it, honestly. Published is definitely faster, but also does things that look like they lose time... That boss seems to spawn quickly, and since the screen transition puts us too far ahead, getting knocked back left, or hitting a wall like they did would help. Something i should've done. S6 Boss: Bad boss RNG for once. I think this is the only boss loss (lmao) in the run? How hard is it to manipulate bosses? It is not hard. I kind of just learned that a little too late. Most bosses could have a few frames saved as well. At this point, i might as well just restart. hahaha

That way of skipping bosses reminds me a lot of Zook Man ZX4 (GBA) during DTC6, where we had to coax enemies into a position so that we can kill them just as the boss spawns, tricking the game into thinking it was the boss that died. I'm not sure how similar the trick actually is, but this is the first thing it reminded me of when I saw it. It's a cool trick that is very hard to find, and I will of course vote yes.

At this point, i might as well just restart. hahaha

Should I delay this and wait for an improvement file, then?

Yeah, i decided to do it again. I'll be complaining from time to time about the game's mechanic in the Discord server

I think you can cancel your submission and edit the submission text saying new improvements found and you are redoing the TAS. edit: I guess I could also look into this game and check the TAS in case you would like to collaborate with me. edit2: - to minimize lag frames, you can jump higher without losing time. the height required to avoid a lag seems to be dependent on other enemies around the same positions horizontally drawn. There is no real rule apart from trying to change the jump heights to change the starting floor position of the next jump. edit3: I've started to transform my Hokuto no Ken hud script from fceux to this game for bizhawk but currently it has a fatal bug, will update it maybe tomorrow. User movie #73111147014864254

Neat! I also made myself a simple script that just shows me some values, and made it yell at me in red if screen lag is detected. It's poorly written, but i had no intention of releasing the script anyway. just the addresses. The warning stays on screen for 2 seconds, with the timer being visible. The timer is red for the first 30 frames, and then becomes yellow. Rewinding clears the warning. This is what i have at the moment: -Camera position, except mine uses 0020 instead of 0026. -0084: A timer that is used for one of the two sprites exploding, when to resume a game when a miniboss is defeated, or when go to the next level after defeating a boss. -007A: Might be an enemy's x position on screen? This is what i use to skip bosses. When i punch enemies, and stay right next to them, it seems to randomly change between two values. When this happens, i just activate the boss when it shows one of two values, and if it is correct, the bosses glitch out. If not, then i just wait until the other value shows up to activate the bosses. Sometimes, it might not change at all. So punching the enemies at a different position or timing might change this. Update from last TAS: Seems like i only need one enemy's explosion timer to be above 80, but i still need to punch the other one. I can just do it much later. That saves some time, as long as the correct enemy gets in my face first to receive a free punch in the face. -0385: This needs more investigation, but it seems to be some kind of timer that has to do with enemy spawning? It decrements by one or two depending on how many enemies are on screen, and then stops at a certain low value?

Haha, for other TASes I used to draw a red rectangle over the screen when the character has 0 X position change, this way I can see the red flashing while turboing through the movie. According to my notes, if I'm not mixing up this with another NES game (Rush'n'attack), these were the values for hokuto no ken and my new ones for fist of the north star: x pos 0x60b 0x613 y pos 0x60c 0x61c camx 0x24 0x26 p alive 0x500 (32 projectiles according to my notes, might be only 16 max) N/A p x 0x523 N/A p y 0x525 N/A I will start gathering enough memory values and fix the crash and then we can continue doing this. For me it's ok if we communicate through this thread or through PMs, my plan would be something like: - get all required memory variables for the HUD script - make a comparison notes for previous TAS (starting frame numbers for each level and their duration) and this TAS - start reworking the levels one by one (it looks like the game is somewhat hex-edit friendly: it's possible to change minor inputs without heavy attempts to resync it, but I always prefer to get every tech implemented as early as possible to avoid headache later) edit: watched the previous 2 TASes of this game and I think I can guess what is that animation timer. In NES Hokuto no Ken, if I recall correctly, depending on how much you killed the boss (getting his health to 0 or making an overkill, damaging way more) will get a different animation. I suggest to use this video to understand what I'm talking about and then read my line: (watch this from 1st boss start to 1st boss end) Link to video Animation 1 - damaging a lot but his health not reach 0, explodes and a Japanese text appears (for example for the 1st boss: Hokuto Jūha Zan (北斗柔破斬, The North Star Softness Ripping Slash) (watch this from 0:00 until 0:20. you can see on the right side that the first 21 seconds is recorded in one take. the video uses cheats, so he able to bring the boss health to 0) Link to video Animation 2 - damaging his health to 0. if this happens, the health bar also shows 0 and there will be no Japanese text being shown on the screen. Animation 3... now this is where I'm not sure about my memory. I believe it's possible to overkill the boss (his health value went from 0 to negative) and the animation was much shorter... I don't have my WIP as I've formatted my tasing drive mistakenly, but I guess this isn't important regarding our case of tasing the next game in the series. edit2: This would somewhat answers why there is a timer that gets reset, which probably used as "Did Ken beat him in N seconds while hitting him M times?". Probably because while I TASed the game, I was able to make very fast, all hit combos which made possible for me to see the 3rd type of boss death. edit3: versions: NES Hokuto No Ken has 2 versions, normal release and beta version. TCRF (unsure if I can link that page due to the no linking to copyright stuffs) accounts this as prototype and only the number of trailing digits are different. NES Hokuto No Ken 2 is the Japanese version of NES Fist of the North Star. TCRF says the main difference is Japanese texts and the credits also shows a picture of Lui (the girl who Ken rescues, she is the twin sister of Lin. Lin is the first girl from the first episode of the anime, when she meets Kenshiro in the prison IIRC) edit 9: I watched multiple videos and none of them depicted Liu... might by a mistake from TCRF. The following differences mentioned in the FAQ TCRF:

The Japanese version is harder because projectiles are randomly thrown at you from the sides of the screen like in the previous game and the first two mini-bosses have to be hit in their heads. Kenshiro's color was changed from black to blue. The "abeshi" and "hidebu" power-ups were changed to white and black stars. The NPCs that appear at the end of some stages were removed for the US version. In the Japanese version, when you use a continue you are dropped in Stage 4. In the US version, you continue from the stage you were on.

edit 10: Dying on 1st stage doesn't gives the ability to continue... Couldn't verify this last line where we would continue on stage 4. I believe this means this only happens if you already beat stage 3. NES Hokuto no Ken 3 and 4 is an entirely different game, similar to those classic Japanese top view, overworld map walkable stuffs, but much better than those cheap Chinese bootlegs. edit4: NES Hokuto no Ken 2 (japan version) tests Killing two guys whos explodes to glitch the boss: - if one guy explodes and another guy explodes later while going through the "start miniboss" camx pos, the boss will die after 3 seconds and it looks like the two guys turns in to a flag that goes upwards. Enemies and projectiles will spawn as usual. - if both guy explodes and we go through the "start miniboss" camx pos (it looks like I need to be closer to that camx pos to get this effect everytime I test this), the boss fight ends after 3 seconds and the boss' sprite will remain on the screen until we enter another screen. Enemies and projectiles won't spawn until entering another screen. edit6: (they actually spawn but instantly die as soon as drawn) edit5: LOL, I just realized that this might be a potential time save, as none of the TASes did this on the first miniboss. Both effect can be done in Fist of the North Star as well. The glitched sprite looks a little bit different but it also showed something flying upwards from the two guy killed. Only had success with once (I'm using a savestate and replicate the glitch in real time), there is a tricky timing in how much frames spent between killing the two guy. So far I believe the USA version of the game should be used because of not using that cutscene after each battle main boss 1, main boss 2, main boss 3, main boss 5 (different cutscene), main boss 6. All of these cutscenes are cut in the USA version. notice around 1:57 in following video Link to video edit11....: Screen lock bypass: - Works in NES Hokuto no Ken 2. I've tried it on level 1. Went left as far as I could but nothing useful found until I died from the timer hitting 0. Enemies and projectiles won't spawn. The screens getting loaded seems to always use correct level data but they get loaded from seemingly randomly places. Since nobody spawned, the miniboss and boss also not spawned. Need to test more to be sure, might save time if we figure out does it required to spawn both miniboss and boss to be able to skip the level using the main boss double ko glitch The cam x position rolls over from 0 to 65535 and down. Since the bosses seems to be cam x pos dependent on when to spawn, they probably cannot be spawned arbitrarily. I guess the video you show in your first post in this discussion thread (bypass screen lock and fight main boss 2? not really familiar with this game so far) has the right cam x pos either because it's already positioned somewhere 65535 or the starting cam x position is already bigger than 255. Up to stage 6, it looks like the cam x pos gets increasing for each sequential levels, which then gets 0. Some screen transitions adds 255 or a bit higher values for example when going through stairs or going to the next level. Stage 1 cam x pos 0 to 3840 Stage 2-4 cam x pos 0 to 3410 (cam x pos 3326~3410 where you do a fancy out of bounds trick and then you go back to 1404) Stage 5 cam x pos 0 to 6400 Stage 6 cam x pos is 0 to 13570 Stage 7 cam x pos 0 to 4860 Final stage cam x pos 0 to 258 final edit to this post: Here is the 1st level breakdown between the previous TAS and the current TAS. https://docs.google.com/spreadsheets/d/1GvTYgRjMsYSk8Jt3U8HjL7OphKcUWiGyy1YvzwCwFW8/edit?usp=sharing So now the following needs to be done before I start optimizing (minimizing lag frames caused by other enemies present in the same horizontal lines as Ken): - Check if delayed double kill explosion for 1st miniboss --> is it faster to manipulate two enemy there and using this glitch to kill and let projectiles and enemy spawn (required for 1st boss skip) - Check the remaining differences between Japanese and USA version. The Japanese version has both benefit and problem by much more projectiles being spawned. This increases the opportunity of dmg boosting while introducing a bit of lag - Settle at one of the versions between Japanese and USA - Make a test movie with the delayed double kill explosion for 1st miniboss to investigate why it's possible to get this alternate effect

I'll keep updating this post with the new times i currently have, with the spreadsheet you uploaded.

• 1st miniboss end (99): 1441. Enemies spawning close enough to the miniboss made it possible to glitch the boss, and skip it, saving frames.
• 1st boss end (lag frames): 2854. If enemies at the end had their positions switched, i would've been able to save even more frames. Both of them need to be exploding(doing the noises), but really only one, (the correct one) need to be already exploded.

Link to video This is not part of the TAS. Enemy positions were modified for demonstration. If "That number thingy" stays at a high value, then the boss might glitch or spawn weirdly. 007A(thingy) and 0084(Splode timer) seem to handle both enemies, at least, and seems to always be trial-and-error with them, but so far, they haven't disappointed me. I should probably rename "thingy" to something like "sprites X position".

• Level 2 start (colors ready): Old: 3036. New: 3004
• S2 miniboss end (99): Old: 4887. New: 4826
• S2 (or S4) boss spawn: Old: 6109. New: 6007
• S2 (or S4) end: Old: 6429. New: 6344 (17 frame loss because bad Boss RNG. This was the best out of many attempts.)

I'll take a break here.

I don't seem to get any differences on their animation, or timer, if i bring their health to 0, or do the other stuff. Their health won't go into the negatives either. So, something that disappointed me yesterday is that, even in the US version, i cannot attack the bosses' weak point, because that will prevent me from going to the next stage when doing the death glitch. The timer at 0084 gets reset at some point, but nothing happens. In the japanese version, it resets, and shows japanese text at the top. So attacking their weakpoints makes you lose more time in both versions, if someone does a no-glitch run.

Note that the animation differences I mention is from NES Hokuto no Ken. The Japanese text you see in NES Hokuto no Ken 2 is the same as in NES Hokuto no Ken, it's the name of the killing technique you or the boss used, depending on who killed whom. I don't know what happens at double ko glitch. I'm pretty sure that the Japanese version is the original (first released) while the American version is the easier, cut version. This might means that a change like removing the Japanese text affects the double ko glitch which helps us (as long as the observation was correct and the double ko glitch doesn't happens in the original Japanese version but in the American version we use). Here's my current lua script: User movie #73194288044847889 Still looking at the correct size and number of enemy object data, also the BizHawk crash seems to be not my fault albeit I tried to fix it but seems unfixable from my side (from lua scripting). Here's more notes about this and some Japanese version stuffs: strategywiki https://https://www.neoseeker.com/hokuto-no-ken-ii/faqs/95151-hokuto-no-ken-2.html edit: it looks like there are different lag levels... there are frames where Kenshiro (or the camera) only moves 1 or 0 px horizontally while vertically still moving. And there are lag frames where Kenshiro moves 2px but nothing else. So I need check the debugger to see what makes these difference. edit3: latest hud script with objects and lag indicators User movie #73199531389776805 edit 4: reinvestigated lag frames: 2 different lag levels in your submission movie (not every occasion mentioned, only selected a few examples) Horizontal lag frame 310, 368, 414, 644, 686 --> Kenshiro/camera only moves vertically (frame 686 uses 1st lag indicator) Half horizontal lag frame 2339, 2350 --> Only Kenshiro/camera moves 1 px horizontally. The next frame will be also 1px horizontally

Latest, v4 hud script: User movie #73201490362265633 Currently doesn't checks for half position lag. Also doesn't accounts going to left, so might report lag erroneously. Checked your submission up to frame 2550: 8 frames with horizontal lag 300, 310, 368, 414, 644, 686, 2362, 2544 one more edit: sheet link: https://docs.google.com/spreadsheets/d/1GvTYgRjMsYSk8Jt3U8HjL7OphKcUWiGyy1YvzwCwFW8/edit?usp=sharing Made 3 movies with 3 different strategy for 1st miniboss (edit: all movies will desync after the mini boss fight) and it looks like the best strategy is do a double enemy kill and start the fight at the right time to make him not spawned down (need to check if my hud script really works). WIP2 using your submission file but removing all lag frames up to 1st miniboss User movie #73202434469889014 WIP3 using WIP2 but delayed explosion. 40 frames slower User movie #73202494606517660 WIP4 using WIP2 but double kill explosion. 41 frames faster! User movie #73202511855948771 Note in WIP4 (which is the fastest strategy so far) uses the "boss not spawned" stuff I found while testing the Japanese version (edit:) so enemies will still spawn. I will continue researching on Monday.