Nukey Shay Posted March 19, 2004 Author Share Posted March 19, 2004 Color bands are -almost- correct. The invaders will shift color every 1.5 drops (so the red color might not be visible until the last invader is running very close to you). Order follows the arcade...Green, cyan, purple, yellow, red. Cleared out the death animations, and replaced them with one frame (per arcade). This resulted in a savings of 81 free bytes still unused. I still haven't touched sounds yet. Quote Link to comment Share on other sites More sharing options...
NE146 Posted March 19, 2004 Share Posted March 19, 2004 How about the number of steps down it takes to invade? Right now they jump pretty quick to invade earth. Not that it'd be necessary, and from the amount of invaders (which is pretty small) perhaps it's a better thing to leave it that way. But out of curiousity how easy would that be to modify that.. say to add an extra step where they're REAL close just above the players ship like when you do the death row in the real version. Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 19, 2004 Author Share Posted March 19, 2004 Not really. If I altered that so the invaders had more steps to do, the game would become too easy (since there's only 36 invaders). And I tried moving the invaders so that they'd be closer to the player's base, but then missiles from both sides had a tendancy to miss their targets...since hardware collisions are being used to check for those. BTW The game loads a step value from a table LFD39 to determine what vertical position they should be in (i.e. how many scanlines to skip). It goes by 16 scanlines at a time. Quote Link to comment Share on other sites More sharing options...
NE146 Posted March 19, 2004 Share Posted March 19, 2004 the game would become too easy (since there's only 36 invaders). Yeah that's what I figured. Just wondering if you had checked it out or attempted it and I see you did Quote Link to comment Share on other sites More sharing options...
uosipa llamxew Posted March 20, 2004 Share Posted March 20, 2004 The color bands are awesome!!! About larger UFO's, I'm not sure what you meant by mirroring. You mean using 2 sprites instead of only 1? That's getting into the kernal issues that Thomas mentioned...in order to add something in, you need to subtract something else. In display kernals, many games use NOP instructions or loops to waste a certian amount of time...and there aren't very many of those it seems Take even 1 cycle too long during sprite positioning, and the display ends up garbled. From your response, I think you understood what I was saying, but just in case I'll explain. I was thinking after you get so many points that the sprite used for the UFO might switch, so that the disappearing UFO looks different. To make the UFO look more like the arcade, the sprite would only be half of the actual bmp... and the other side drawn would just be a flipped copy of the same sprite. [edit] I was just thinking... maybe you could get the bigger UFO by stretching the sprite - like difficulty A does to the cannon? Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 20, 2004 Author Share Posted March 20, 2004 It would be worse IMO. If I stretched the UFO sprite, it would be lower in resolution (more blocky), and it would be way easier to hit (it's already pretty easy). No chance in adding the smaller split invaders. In order to implement those, I'd need to be able to get more than 6 invaders in a line...and this kernal isn't designed to do more than 6. Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 20, 2004 Author Share Posted March 20, 2004 Corrected the color bands. Due to how the routine fetches values, the invaders will not shift color in one instance: When a full column of invaders shifts from position 3 (3 steps above the base) to one step lower. No biggie. The rest works properly. 76 bytes free. The sounds are really tricky. The program loads 4 values at a time...the first is a "match" value (i.e. how many frames to wait+current frame), followed by the frequency, distortion, and volume. So arcade sounds are going to be tough to get in Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 20, 2004 Author Share Posted March 20, 2004 It's hard to come up with sounds I lengthened the thump, shot, and explosion sound. I tried to pull off a convincing >thump<...but I can't figure out how to get the sounds low enough. Same story with the UFO...I can't seem to reach the mBWAHwahwah of the original. The program is still only allowing 2 frames for the hit invader sound, so I haven't touched that yet. And the missiles don't have the right distortion yet...but it's getting closer. Explosion is nearly correct now I also changed the bitmap for the mystery ship to be kinda sorta what it's supposed to look like above. Not enough detail in 8 bits This is subject to change if I can work out a random routine (which would take more cycles...yada yada)...so I might have to go back to using only 1 type of ship. Quote Link to comment Share on other sites More sharing options...
Krytol Posted March 20, 2004 Share Posted March 20, 2004 I can't stop playing this hack! Awesome! Quote Link to comment Share on other sites More sharing options...
uosipa llamxew Posted March 20, 2004 Share Posted March 20, 2004 I can't stop playing this hack! Awesome! Agreed! I finally rolled Space Invaders for the first time today. Yah, I know, everyone else did that ages ago. I doubt if I'd ever have played long enough had it not been for this hack. (Of course, double shots made it much easier for me too. HAHA) The death explosion is MUCH better! When you die, it is much more satisfying to know you went out in a bang than an accidental squeezed-off fart. The shot sound is definitely closer too. Even though it might not be incredibly accurate, I think the second UFO sprite looks pretty cool! The only things I've noticed that might not be appealing is the horizon line that the cannon moves across is 2 or 3 times what it is regularly and flickers a bit. It's not that distracting though, just something I noticed. Also, some of the invaders antennae tips are a different color than the rest of their bodies, and some of the invader death explosions are also multicolored. Again, this isn't a problem at all, but I didn't know if you were getting the same results using Stella. I am using z26. Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 20, 2004 Author Share Posted March 20, 2004 Thanks for the encoragement guys! The death explosion is MUCH better! When you die, it is much more satisfying to know you went out in a bang than an accidental squeezed-off fart. The shot sound is definitely closer too.Not as close as I would like...but getting there. I hate coding sound...it's largely a hit-and-miss affair. The only things I've noticed that might not be appealing is the horizon line that the cannon moves across is 2 or 3 times what it is regularly and flickers a bit.Yup...the flicker is coming from the time it takes to do the thump sound. It looks like the ground is shaking, which is why I never tried to fix it Another "feature". It's not that distracting though, just something I noticed. Also, some of the invaders antennae tips are a different color than the rest of their bodies, and some of the invader death explosions are also multicolored.Yeah, the invaders with the antenna use the entire stretch of 10 bytes in their bitmaps...and the color change happens just a little too slow (so they will be colored the same as the alien above). I couldn't manage to sneak some extra cycles in to move the color change routine, but since it only happens at that point, it's not a serious glitch. The explosions will be the same color as the rest of the row...no way to change that. Another update...corrected point values This time I fixed the mystery ship. When it turns off, you will not be able to hit it And it scores a straight 500 points (or 200 in games 33-48 ) The regular ship scores multiples of 50 points now...between 50 and 300 like the arcade (according to KLOV). Seems I had that random score routine reversed! This value will only be between 50 and 150 in games 33-48. In order to implement the mystery ship -non-collisions, I had to rob a few cycles before the positioning routine. Yell if this causes any screen jumps (I haven't noticed any...but there's a slim chance I suppose). Next update will feature shot counting if I can track down a spare ram byte...stay tuned! Quote Link to comment Share on other sites More sharing options...
NE146 Posted March 21, 2004 Share Posted March 21, 2004 Just a quick question. Any chance to make the double shots an option? I mean they ARE fun and all, but real space invaders only allows you one shot at a time p.s. Everything about this by the way is totally AWESOME Nukey. Quote Link to comment Share on other sites More sharing options...
uosipa llamxew Posted March 21, 2004 Share Posted March 21, 2004 Just a quick question. Any chance to make the double shots an option? I mean they ARE fun and all, but real space invaders only allows you one shot at a time Use the right difficulty switch. This hack makes me want to seek out an old Track and Field controller. :-) Maybe I'll even cover up the old decals with some arcade Space Invader cabinet art! Quote Link to comment Share on other sites More sharing options...
NE146 Posted March 21, 2004 Share Posted March 21, 2004 Just a quick question. Any chance to make the double shots an option? I mean they ARE fun and all, but real space invaders only allows you one shot at a time Use the right difficulty switch. Doh! Guess I should read Nukey's posts a little closer This hack makes me want to seek out an old Track and Field controller. Ugh! You must like the old "Button control" of the Midway version. Of course however the original S.I. used a nice fat JOYSTICK But still, hmmm that kind of sounds like a cool enough idea. I remember struggling with the Midway controls as a kid when I went out to the states and checked it out at some Greyhound station. Would be kind of cool! Actually getting that darn T&F controller in and of itself would be cool for me. Hmmmmm Quote Link to comment Share on other sites More sharing options...
uosipa llamxew Posted March 21, 2004 Share Posted March 21, 2004 Ugh! You must like the old "Button control" of the Midway version. Of course however the original S.I. used a nice fat JOYSTICK But still, hmmm that kind of sounds like a cool enough idea. I remember struggling with the Midway controls as a kid when I went out to the states and checked it out at some Greyhound station. Would be kind of cool! Actually getting that darn T&F controller in and of itself would be cool for me. Hmmmmm Actually, I've only played Space Invaders at the arcade maybe once or twice... and never played with a stick. I use a Genesis stick quite often with my VCS now... I just needed a reason to get the Track and Field Controller. :-) ... actually, I just nabbed up one that Povlok1 had listed on eBay... it's very mint and cool looking. I won't be sticking a decal over the top of the old one, but I might make a nice overlay. :-) Now I just need a Supercharger. LOL! BTW... is there an arcade in Seattle with classic arcade games? I haven't been able to get out much since I've lived here. Maybe I can check some out before I move away in two weeks. :-P Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 21, 2004 Author Share Posted March 21, 2004 OK...I had to "borrow" a stack location to count the player shots. Unfortunately, I couldn't figure out how to make the counter increase when a missile is fired...so I increased it when an invader is hit. When you first boot the game, the counter is at zero. Every 16 invaders, it rolls back to zero. Only invaders hit when a UFO is NOT on the screen count, so you can't have a UFO change from one to the other in mid-flight. If you start the game over, the counter will be in a random spot If you hit the mystery ship, the counter will bump up one notch (so you can't just sit around and collect mystery ships). Other UFO's don't count. To see an example, boot the game and don't shoot any aliens. The first UFO that appears will be a mystery ship. Once you hit it, you'll need to hit 15 more invaders when no UFO's are on the screen to get another one. And then 15 after that, etc. Since the stack location is active when the game is restarted, the counter will be in an unknown state. I dunno if I can change that to be the start of the game yet...but I should be able to clear that location when a new game is begun (I haven't yet found the seperation between new game/new board yet). To save confusion, I've put the binary waaaay at the start of this thread. Sorry for making you guys run around Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 21, 2004 Author Share Posted March 21, 2004 This hack makes me want to seek out an old Track and Field controller. Ugh! You must like the old "Button control" of the Midway version. Of course however the original S.I. used a nice fat JOYSTICK That's nowhere near as bad as some cocktail Midway Deluxe machines...that used a little slide lever to move (one that was mounted flush with the panel and swung 45 degrees to either side). Totally kills the thumb. Quote Link to comment Share on other sites More sharing options...
NE146 Posted March 21, 2004 Share Posted March 21, 2004 <off topic post moved to prvt msg> Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 21, 2004 Author Share Posted March 21, 2004 OK...I tried something different... Since that would cause more wear on power switches, I've cleared the shot counter and started it at 1 on game reset in this version. Which means that you will have to shoot 15 invaders before the ship appears. Also, since the previous version skipped over the regular UFO's, it would make the chances of the ship appearing very slim...so I counted them as well. Which is better do you think? I also fixed the shaking ground, made it a full line that extends the length of the screen, and adjusted the end-of-movement markers to line up better to the players. Hopefully, the number of scanlines won't be a problem (this possibly adds 1) si_shot2.zip Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 21, 2004 Author Share Posted March 21, 2004 ...or does the ground look better as a thicker bar as seen in the arcade game? EDIT: scatch this one...can't get enough cycles to keep the shields from glitching. The thin bar works OK tho. Quote Link to comment Share on other sites More sharing options...
neotokeo2001 Posted March 21, 2004 Share Posted March 21, 2004 I like the thin bar better, but I miss the strobe effect it used to have. An all around incredible hack. Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 21, 2004 Author Share Posted March 21, 2004 Something puzzles me. You know how games can have multiple kernals and use the frame counter to decide which one to jump to? I wonder why nobody ever attempted to create a game that uses that method to get 12 30hz characters across the screen? That same frame counter could also be used in other redundancy routines (like collision detections, etc.) It would be bigger than 4k, but the ram should be able to hold out More complex than I could do tho. Quote Link to comment Share on other sites More sharing options...
uosipa llamxew Posted March 21, 2004 Share Posted March 21, 2004 It gets better all the time! While playing today, I started wondering if there would be any way to hack the game to cycle to a different (maybe even random) level variation each time you clear a screen? Something puzzles me... And now I'm puzzled! Maybe Thomas would know. Thom? Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 21, 2004 Author Share Posted March 21, 2004 While playing today, I started wondering if there would be any way to hack the game to cycle to a different (maybe even random) level variation each time you clear a screen? Easy. The level variations are really only held in 1 byte...and just flipping bits on or off determine the variation. So you could grab something that always updates...like the frame counter or something else...trim off the bits not needed, and then EOR it with that variable. It might not be such a good idea tho...as some of the variations are downright unplayable at the highest level (like fast diagonal bombs)...and some variations would seem to have no effect at all (like the shields that move). Quote Link to comment Share on other sites More sharing options...
neotokeo2001 Posted March 22, 2004 Share Posted March 22, 2004 Here are a few screen shots of the latest SI Vector Deluxe. It is the latest version of Nukey Shays SI Deluxe with a few minor changes. siv_deluxe.zip Quote Link to comment Share on other sites More sharing options...
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