Cybergoth Posted January 5, 2006 Share Posted January 5, 2006 Hi there! In the tradition of this (annual ) series of articles after: Concepting a Conversion #1: Fire One and Concepting a Conversion #2: The Dreadnaught Factor I'd now like to start some discussion regarding the Taito Arcade game Space Seeker. The game consists of three different types of screens: The world/overview screen, a spaceship cockpit scene and a scramble like scene. The game has an almost RTS quality flow: On the map scene you can freely move around and engage enemies, then it switches to either pseudo 3D space shooting or the scamble scene. Let's start with the map scene: It shows a world map, your (squared) home base with 5 defending ships, a bunch of sattelites and 3 enemy... hm... dreadnaughts? As soon as the game starts, the dreadnaughts launch enemy fleets. See the red dots in this picture: The dreadnaughts may also try to shoot the defender, before you manage to engage them. The sattellites just float around their orbits, occassionally blocking your path. If they hit you, you get paralized for a few seconds. Ok, so much for the introduction. How would this screen translate to the 2600? Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
vdub_bobby Posted January 5, 2006 Share Posted January 5, 2006 (edited) How would this screen translate to the 2600? Badly. Oh, I couldn't resist. More seriousness to come later... EDIT: Question: Where is the defender (the player-controlled ship, I assume) in those pics? Edited January 5, 2006 by vdub_bobby Quote Link to comment Share on other sites More sharing options...
NE146 Posted January 5, 2006 Share Posted January 5, 2006 How funny.. this is exactly the game when I was a kid I had hoped I would eventually be able to play on my Atari. Of course it never happened, and today I too wonder if it even could be done. But then again I've seen other miracles from you Cybergoth... so I'll be watching Although I think a translation of Space Chaser would be easier to do (even though it wouldn't be a new type of game for the VCS).. that, or Scramble :-) Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 5, 2006 Author Share Posted January 5, 2006 Hi there! EDIT: Question: Where is the defender (the player-controlled ship, I assume) in those pics? The small circles with the red cross. Your reserve fighters are in the rectangle. On the second picture one is flying right of the rectangle. The screen elements are rather iconic here, it's really more of a map for plotting your next move Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 5, 2006 Author Share Posted January 5, 2006 Hi there! Although I think a translation of Space Chaser would be easier to do (even though it wouldn't be a new type of game for the VCS).. that, or Scramble :-) What I don't like about Space Chaser, is that you can't *play* it, as it really comes down to be just try & error pattern memorization, no? Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
vdub_bobby Posted January 5, 2006 Share Posted January 5, 2006 (edited) The small circles with the red cross. Your reserve fighters are in the rectangle. On the second picture one is flying right of the rectangle. The screen elements are rather iconic here, it's really more of a map for plotting your next move Ok; I see. Thanks. So you've got a big ~2-colored background, approximately 9 independently moving large objects, 3+ (?) independently moving small objects, plus the stationary homebase. I'd say use a striped, alternating color, reflected PF for the background (earth). Use M0 for the defender maybe...with P0 for dreadnaughts and P1 for satellites. M1 for enemy fleets. Use clever movement patterns to prevent flicker. Or use intelligent flicker. For the homebase; not sure. Could draw it with the PF. That might be too ambitious; that's a lot of objects. Maybe striped, single-color PF for the earth. Edited January 5, 2006 by vdub_bobby Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 5, 2006 Author Share Posted January 5, 2006 Hi there! For the homebase; not sure. Could draw it with the PF. I thought to just get rid of the homebase and display the remaining extra lifes at the bottom of the screen, just like any "normal" game Here, I just finished creating this "empty" world picture: It's using 8 colors and lotsa 8x8 tiles for the display. Question for an artist: Is it possible somehow to "undither" this for a clean look? After all the 2600 has 128 colors! Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 5, 2006 Author Share Posted January 5, 2006 Hi there! Question for an artist: Is it possible somehow to "undither" this for a clean look? After all the 2600 has 128 colors! Ah, halfway there! It seems "undither" is called "mosaic" in PSP This is what we'd get if each PF pixel could have its own color: Trying some other PSP filters now... just wait and see, we'll get that done somehow... (Actually, is this something we could get displayed as is with Andrews greeting cart methods?!?) Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 5, 2006 Share Posted January 5, 2006 (Actually, is this something we could get displayed as is with Andrews greeting cart methods?!?) Yup. Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 5, 2006 Author Share Posted January 5, 2006 Hi there! (Actually, is this something we could get displayed as is with Andrews greeting cart methods?!?)Yup. Hm... would that technique also work, if every second line was black? (How does it work actually? ) As is, this is 29 PF pixels wide, requiring only PF1+PF2 and I somehow try to find a way to work sprites+repositioning scanlines in Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
vdub_bobby Posted January 5, 2006 Share Posted January 5, 2006 As is, this is 29 PF pixels wide, requiring only PF1+PF2 and I somehow try to find a way to work sprites+repositioning scanlines in Were you thinking of an asym playfield? Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 5, 2006 Author Share Posted January 5, 2006 Hi there! As is, this is 29 PF pixels wide, requiring only PF1+PF2 and I somehow try to find a way to work sprites+repositioning scanlines in Were you thinking of an asym playfield? Symmetrical register layout, Assymetrical image Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
vdub_bobby Posted January 5, 2006 Share Posted January 5, 2006 Symmetrical register layout, Assymetrical image Ehhh. I'd like to know how you'd work that! Quote Link to comment Share on other sites More sharing options...
uosipa llamxew Posted January 5, 2006 Share Posted January 5, 2006 Symmetrical register layout, Assymetrical image Ehhh. I'd like to know how you'd work that! 994760[/snapback] I don't know anything about how possible or ridiculously hard it would be to get it to display, but I threw something together with the VCS color pallete: Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 5, 2006 Author Share Posted January 5, 2006 Hi there! Symmetrical register layout, Assymetrical image Ehhh. I'd like to know how you'd work that! Are you joking with me You just reflect the playfield to PF0/PF1/PF2/PF2/PF1/PF0 and the register layout is symmetrical, no? Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
vdub_bobby Posted January 5, 2006 Share Posted January 5, 2006 Are you joking with me You just reflect the playfield to PF0/PF1/PF2/PF2/PF1/PF0 and the register layout is symmetrical, no? I meant how you are going to display a colored, asym playfield while simultaneously drawing ~10 moving objects over the top of it. Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 5, 2006 Author Share Posted January 5, 2006 Hi there! I don't know anything about how possible or ridiculously hard it would be to get it to display, but I threw something together with the VCS color pallete: Hm... unfortunately that's going to be almost as complicated as the one I posted. As soon as there's more than 1 color per scanline it get's tough... I meant how you are going to display a colored, asym playfield while simultaneously drawing ~10 moving objects over the top of it. Ah, that. Well, Andrew does it in BD with 1 sprite, Rockford. With keeping every other scannline black you might just manage to reposition and multiplex sprites. Admittedly, I don't know yet how his technique works, I've to do some homework there first Edit: Hey, we could do it just like the flashback programmers! Show the left half of the globe on frame 1, the right on frame 2, the dreadnaughts on frame 3 and the satellites on frame 4! Can't release it as homebrew then, but Atari might pay some for it Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
vdub_bobby Posted January 5, 2006 Share Posted January 5, 2006 (edited) Ah, that. Well, Andrew does it in BD with 1 sprite, Rockford. With keeping every other scannline black you might just manage to reposition and multiplex sprites. Admittedly, I don't know yet how his technique works, I've to do some homework there first He used a 64K cart and bankswitched during his kernel, if I remember correctly. In BD he didn't flicker anything - he displayed different colors on different lines. I don't think that will work very well with blank lines. If you do come up with a sprite-repositioning routine that can draw an asym playfield while repositioning sprites, please let me know. Well, one that doesn't take 10 scanlines. EDIT: Hey, we could do it just like the flashback programmers! Show the left half of the globe on frame 1, the right on frame 2, the dreadnaughts on frame 3 and the satellites on frame 4! Can't release it as homebrew then, but Atari might pay some for it. Oh....my... If you're going to do that, why not just hack Pac Kong? Atari pays for poorly written hacks, too. Edited January 5, 2006 by vdub_bobby Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 5, 2006 Author Share Posted January 5, 2006 Hi there! If you do come up with a sprite-repositioning routine that can draw an asym playfield while repositioning sprites, please let me know. Well, one that doesn't take 10 scanlines. Keep watching TJs blog Edit: And didn't we just see it in the new Caverns of Mars? Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
vdub_bobby Posted January 5, 2006 Share Posted January 5, 2006 If you do come up with a sprite-repositioning routine that can draw an asym playfield while repositioning sprites, please let me know. Well, one that doesn't take 10 scanlines. Keep watching TJs blog With self-modifying code, a lot of RAM and a lot of ROM, you could write code like this: cpy NextRepositionLine bne NoRepoThisLine jmp RepositionRoutine ;<--self-modify this address NoRepoThisLine Where RepositionRoutine is the address of one of many repositioning routines with the STA RESP0/1 hardcoded. That routine would have to modify the JMP instruction above to point to the appropriate RepositionRoutine for the next sprite. And I suppose something goofy like that would be feasible in a regular cart, you'd just have to change to: cpy NextRepositionLine bne NoRepoThisLine jmp (JmpAddress) ;<--zero page address that is modified by the routine NoRepoThisLine Just have to reserve two bytes of RAM for the JMP address and have lots of ROM for all the positioning routines. Hmmm..actually, that's somewhat feasible. Edit: And didn't we just see it in the new Caverns of Mars? What did we see there? I'm certainly curious. I think there were at least two, possibly three kernels on display there, not even counting the title/score screens. #1. kernel had an asym PF (PF1+PF2) with repositioned sprites and no HMOVE lines, no blank lines, and no symmetrical PF lines in between the sprites. #2. kernel had a sym PF with no apparent repositioned sprites (though it might be possible) but two mid-scanline playfield color changes! No HMOVE lines. #3. kernel had a sym PF0 with no apparent asym PF1/PF2 and no apparent goofiness except for lots of repositioned sprites and no HMOVE lines! I've got my money on HMOVE hit at cycle 73, with repeated HMOVEing of sprites in kernel #1 to reposition. Kernel #2 I dunno. Kernel #3 I think standard reposition routine (battlezone). Definitely a skilled coder! Quote Link to comment Share on other sites More sharing options...
mos6507 Posted January 6, 2006 Share Posted January 6, 2006 Definitely a skilled coder! 994822[/snapback] I don't know if you are being sarcastic or not, but the Caverns of Mars looks considerably worse than River Raid. In the end it was a poor compromise. I'm sure it could have been done a different way, maybe more like Thrust. Quote Link to comment Share on other sites More sharing options...
Gateway Posted January 6, 2006 Share Posted January 6, 2006 I still think the world is flat. (see below) Perhaps a display like this could be rounded on the sides and the land masses altered to resemble the game. I remember it being a pain in the neck to get it this far and still look decent( It's asymetric PF, using PF0-PF2, IIRC. It's been awhile ), to say nothing about adding sprite movement, etc. over the PF( though I did try to activate the ball to move inside the landmasses but didn't get very far) . I'll leave that puzzle to you more advanced programmers to solve. Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 6, 2006 Author Share Posted January 6, 2006 Hi there! Definitely a skilled coder!I don't know if you are being sarcastic or not, but the Caverns of Mars looks considerably worse than River Raid. In the end it was a poor compromise. We're talking this version Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 6, 2006 Author Share Posted January 6, 2006 Hi there! I did try to activate the ball to move inside the landmasses but didn't get very far Well, of course that won't work, as the ball would be green as well What was it planned to be? A Globetrotter game? Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted January 6, 2006 Author Share Posted January 6, 2006 Hi there! Hm... a game that ~ does what we want here would be Sea Battle, no? Greetings, Manuel Quote Link to comment Share on other sites More sharing options...
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