Bryan Posted July 4, 2003 Share Posted July 4, 2003 bryde: can you post the binary as well??? so i can check it in atari800win how accurate it is (emkay, i know amidarius is not 100% perfect running on emus) the screenshots look like a 2600 kernel... hve I tried it in Atari800WinPlus, and it doesn't work right. The Emulator doesn't show mid-scan updates properly, so it makes a bunch of horizontal bars, and that doesn't prove anything. -Bry Link to comment Share on other sites More sharing options...
emkay Posted July 4, 2003 Share Posted July 4, 2003 OK. I know, the colorchanging in line 0 of a Charmode is reduced. But, nevertheless, the charmode is needed to create a higher variety in building of an Image and no one will recognize that line if the colors are used right. Link to comment Share on other sites More sharing options...
Shawn Jefferson Posted July 4, 2003 Share Posted July 4, 2003 I've been looking at GED and it looks like it does exactly what we are discussing here, albeit with an Antic E mode. It makes horizontal playfield color changes and one PMG change (size, position, color) per scanline. Supposedly you can "move" in increments of one cycle the horizontal color change position on the screen. There's a TECH.DOC that explains exactly how that works. Was that in the archive posted? Anyway, here it is: The GED graphic format is really in two parts -- player/missles (PMG), and playfield. For the playfield, there is a 10K DLI that continuously stuffs colors into the color registers. The background color isn't changed, but the other 3 color registers can be stuffed multiple times with different values. This creates 9 playfield colors per scan line. A color register value only exists for a portion of the scan line, and it creates what I call a color 'cell'. It divides the screen up into columns, as shown below, and I'll follow it with the DLI code. The scan line will begin with starting colors for all three registers. Next, the DLI pre-loads the first three color changes into A,X,Y. That takes us to pixel #27 on the horizontal scan line. From there, follow the chart below. -- DLI instruction -- LDA # LDA # STA $D016 STX $D017 STY $D018 STA $D016 STA $D017 -- X pixel coordinates -- 31 63 83 107 131 1st set of ! New color 1 ! New cols ! New cols ! 3rd value ! 3rd val colors 0-3 ! and original ! 1-2, and ! 1-3 ! for col 1 ! for 1-2 exist here ! 2-3 ! org 3 ! ! 2nd 2-3 ! 2nd 3 This is the timing of the DLI, but visually, It's more important to see where the color cells are, since that's what you draw with. 1st value of ! 2nd value of color 0 ! 3rd value of color 0 ! ! color 0 1st value of color 1 ! 2nd value of color 1 ! 3rd val ! ! of col 1 1st value of color 2 ! 2nd value of color 2 There is no 3rd value for color 2. I hope you can visualize what this does. It means that depending upon where the cursor is on the line, changing the color register value using the Shift-Arrows only changes the local color 'cell'. It will only change the color on part of the line. Playfield colors are stuffed automatically every line, and so changing a color cell effects only the scan line it is being changed on. The previous values will get stuffed back into the color register on subsequent lines, until those color cells are changed as well, (which can be done with the 'C' and 'W' commands). The pixel positions in the chart are for the default setting. GED now allows you to skew the entire routine left or right, one cycle at a time. This will move all of the pixel coordinates. It goes on to talk about the limitations of the PMG per scan line changes... If there are issues with the first scanline in character modes (you have no cycles to make changes...) that might outweigh the benefits of trying to use a charmode (one extra color? inverted characters additional color?) What is the format of the GED file I wonder? Link to comment Share on other sites More sharing options...
emkay Posted July 4, 2003 Share Posted July 4, 2003 I see a basic program: 1984 Better graphics needed 1990 Is it possible 2000 Hmm... looks complicated 2003 Not necessary 2004 goto 1984 Link to comment Share on other sites More sharing options...
Jetboot Jack Posted July 4, 2003 Author Share Posted July 4, 2003 Shawn, GED sounds great!!! Can u mail me the TECH doc please (jetbootjack@jetbootjack.com), its not in the archive... It sounds like GED will provide 9 colors per scan line, plus PMG for 4/5 more colors -- 14 colors perscaline, AWESOME!!!! I wonder how simple the format is, how easy to set up those color change points so we could make a PC ripper for images -- Photoshop/ripper/Atari 800 sTeVE Link to comment Share on other sites More sharing options...
emkay Posted July 4, 2003 Share Posted July 4, 2003 GED and its technique is to simple. without the 5th color it will not be possible to reach the color-deepness of the C64s.... So once again the ATARI users will proof the C64 is the better computer... Thanks.... I am out of this thread. Link to comment Share on other sites More sharing options...
Jetboot Jack Posted July 5, 2003 Author Share Posted July 5, 2003 emkay -- what's up, your last post sounds rather upset, and final?? Since GED is available and working, its GOT to be worth investigating... Antic 4 and Antic E with PMG overlays offer EXACTLY the same number of unique color registers to use 704-712, all that it means is that 711 is set to the missiles only in ANTIC E mode, wheras in ANTIC 4 you can use it as an alternate playfield color as well.... If GED images are simple to display and work with then they sound just like MCS++, except in bit mapped mode, which is a bit more flexible to create art in than multiple character sets and the like... All anyone on this thread is after is deeper color images so we can do some cool stuff (I was personally thinking about using this in a game rather than a demo ) The RAM overhead for either Antic E with image and Antic 4 with 8 character sets is almost the same too -- about 8/9k, so if GED stuff can be created it looks promising... sTeVE Link to comment Share on other sites More sharing options...
Shawn Jefferson Posted July 5, 2003 Share Posted July 5, 2003 Jetboot Jack: I did a search for it on Bill Kendrick's XL Search (I've attached the arc file to this message for you.) emkay: You can always write your editor and show all backward thinking Atari fans everywhere what the Atari can do. I think GED is a good starting point. I'm no Atari expert but it seems from the discussion that if you are going to have the further constraint of not being able to make any horizontal color changes, or PMG changes in the first scanline of each character mode line that it might make creating pictures and/or converting much more difficult. Here is an editor, already made that does exactly what we have been talking about, albeit in Antic E instead of 4. I'd like to see someone do a really nice picture with it to see what can be done. This guy has already figured out how many color changes and pmg changes can be made per scanline. If Antic 4 is a better way to go, then certainly the techniques he uses in GED can be useful/educational? On the topic of conversion: wouldn't that be problematic? If you have a picture that uses 14 colors there is no gaurantee that those colors will be in the right places to use a mode like this (or would they?) A convertor running on the PC would probably be the best option since it needs to figure out not only where all the colors need to go but always if it is better to switch the color to another playfield register or player missile graphic. I can see it being a multi-pass type thing that finds the optimum setup for playfield graphics, playfield registers, etc... I think it is possible and one of you guys should do it. ged.arc Link to comment Share on other sites More sharing options...
Bryan Posted July 5, 2003 Share Posted July 5, 2003 Here's an idea too... On line doubled modes, you have almost all cycles remaining (except 9 refresh cycles) on the 2nd line, because Antic displays from an internal buffer. If you turned off the colors on the 1st line, then did register stuffing on the 2nd line, you'd get the most color changes, but with the black "blinds" effect, so, you alternate which lines are black from frame to frame. Any thoughts? -Bry Link to comment Share on other sites More sharing options...
Jetboot Jack Posted July 5, 2003 Author Share Posted July 5, 2003 Shawn, Thanks for the archive -- interesting stuff no doubt about it I've read the documentation, it looks pretty straight forward -- I guess its time to pull out the SIO2PC cable and get on with it on the real metal! Under emulation (Atari800Win Plus) the horizontal color "cell" interrupts don't seem to work properly, anyone know of an emu with better screen timing/handling that maybe able to handle GED -- or am I just doing it wrong?? sTeVE Link to comment Share on other sites More sharing options...
Lord-Chaos Posted July 5, 2003 Share Posted July 5, 2003 For lots of colors and good resolution I´d use the character mode with players as overlays. That gives 5 colots + 4 colors = 9 , but also additional 6 colors were players are overlays over the background.(with GPRIOR=0) That means 15 colors without any DLIs in simple BASIC. The disadvantage is that the overlay colors cannot be chosen freely , but if you use the right colors this doesn´t matter. Also possible : -With the right timing,it´s possible to change colors in the middle of a scnaline , but I doubt it will work with more than 2 colors. - It´s possible to display players twice (with different colors) per line with little CPU usage , but some flickering.It´s also possible to use them 4 times (=16 players) , but with very much flickering. - it´s possible to use players twice per line without flickering,but it requires exact timing and this may be a problem when you already using DLIs for color changes. So it´s possible to have about 20 colors without much CPU-time loss , you can´t freely choose all colors , but you can´t do this on the C64 in the IFLI modes etc. With DLIs and color/player position changes every scanline , it should be no problem to use 128 colors. The advantage of charset - graphics with players as overlays is , that you can use this not only for pictures but also fro real games. I mean - on the C64 you can´t really make a game in IFLI , but on the ATARI you could use software sprites with playes as overlays and have games with lots of colors. And you may be able to play digitized sound while displaying because it doesn´t take away all the CPU time. Thimo Link to comment Share on other sites More sharing options...
Jetboot Jack Posted July 6, 2003 Author Share Posted July 6, 2003 Thimo, I don't understand what you mean by: That gives 5 colors + 4 colors = 9 , but also additional 6 colors were players are overlays over the background.(with GPRIOR=0) How do you get 6 more colors with GPRIOR -- the only extra colors I know of are when PMG 1/2 overlap or PMG 3/4 overlap to create a 3rd color -- how do PMG and background create new colors with GPRIOR settings (except black)? I think most of what you describe is already in MCS standard that emkay has outlined, and the GED format gives 9 PLAYFIELD colors perline by using horizontal timing, plus PMG overlays -- 14 colors perscanline. Emkay was suggesting he could do something similar in Antic 4 too... I don't think that we can get a really useable, totally solid-non flickering display and more than 14 colors per scanline. Horizontally muliplexing the PMG would streal away all the CPU time for color register stuffing in GED/MCS++ -- so we wouldn't win anything that way I feel. GED/MCS++ modes would be no use for in game graphics -- far too much processing required IMHO. I have used Antic 4, with PMG and software sprites in other projects -- some of the Harlequin coders did that in Project Xanthien and Menace (see my website), and I agree in game that software sprites in Antic 4 or Antic E plus PMG overlays would give us the most colorful displays just with that and a couple of normal vertical DLI sTeVE Link to comment Share on other sites More sharing options...
Bryan Posted July 6, 2003 Share Posted July 6, 2003 Thimo, I don't understand what you mean by: That gives 5 colors + 4 colors = 9 , but also additional 6 colors were players are overlays over the background.(with GPRIOR=0) Turning off all priority bits causes players to be OR'ed with the playfield. It's a weird & largely undocumented trick. A quick BASIC program could be whipped up to demonstrate it. Make hotizontal bars in a graphics mode (3 will do) and turn on the players (but no DMA for them). Set their data bytes to FF and make them vertical bars over the screen. Set PRIOR to 0 and watch the fun!! -Bry Link to comment Share on other sites More sharing options...
Jetboot Jack Posted July 6, 2003 Author Share Posted July 6, 2003 So GED or MCS could use the GPRIOR trick too -- how can u predict what colors are generated... sTeVE Link to comment Share on other sites More sharing options...
Bryan Posted July 6, 2003 Share Posted July 6, 2003 So GED or MCS could use the GPRIOR trick too -- how can u predict what colors are generated... sTeVE OR the bits. Color $34 OR'd with $18 = $3C Link to comment Share on other sites More sharing options...
Lord-Chaos Posted July 6, 2003 Share Posted July 6, 2003 Yes , this is what I mean. You can use this in simple BASIC. I´ve written a small BASIC program , look at the picture. BTW : 2 overlaying players can also create a third color.This may be useful in special cases , too. Thimo Link to comment Share on other sites More sharing options...
TMR Posted July 6, 2003 Share Posted July 6, 2003 Ooh, that's what i've been trying to do for the last half an hour; can you explain how its done for a coder who only started on the Atari two days ago? =-) Link to comment Share on other sites More sharing options...
emkay Posted July 6, 2003 Share Posted July 6, 2003 OK.. a last suggestion: With the Charmode you have 5 colors that are usable on the full-screen incl. overscan, if necessary.This cost only some CPU clocks... By using of charmode, you save many cpu-clocks by not splitting PMG... which would be multiple cpu expensive if pmg should be used to replace the "fullscreen-color" and if PM will be used with more than one color. In 7 of the 8 Charmode-scanlines you can switch registers over and over. In Line 0 cpu time is heavy reduced, so this will not really problem: You are able to set the PMg in blocks (where the colors are needed). So it is possible to set registers in the 7th Line for Player positions and for charbase... if necessary. You are able by setting of prior, to create "Hell on Earth" You are able to fit small sound- or movement- routines, where no changing is needed... Link to comment Share on other sites More sharing options...
Fröhn Posted July 6, 2003 Share Posted July 6, 2003 GED and its technique is to simple. without the 5th color it will not be possible to reach the color-deepness of the C64s....So once again the ATARI users will proof the C64 is the better computer... to reach the color depth of a c64 you'd need 3 new colors every 2 cpu cycles. Link to comment Share on other sites More sharing options...
emkay Posted July 6, 2003 Share Posted July 6, 2003 GED and its technique is to simple. without the 5th color it will not be possible to reach the color-deepness of the C64s....So once again the ATARI users will proof the C64 is the better computer... to reach the color depth of a c64 you'd need 3 new colors every 2 cpu cycles. Not really... You need the possibility to change colors where they are needed. The most (for up to 128 colors) can be done by overlays.... And that is possible in 160 x192(238) and 16 colors by no handycap. Hires will only be that colorfull with interlace on the XL/XE. Link to comment Share on other sites More sharing options...
emkay Posted July 6, 2003 Share Posted July 6, 2003 RASTER sent me a picture which is only using overlays and some DLIs... The Picture is hires and a fine artwork with the given possibilities. Link to comment Share on other sites More sharing options...
TMR Posted July 6, 2003 Share Posted July 6, 2003 That PMG overlay trick, what happens if you're in 160x200 bitmap? Do all the colours get OR'd with the PMG colour or just some of them...? And how the hell do i get it to work?! =-) Link to comment Share on other sites More sharing options...
emkay Posted July 6, 2003 Share Posted July 6, 2003 @lord-chaos why don't you post the pictures you created? Link to comment Share on other sites More sharing options...
Jetboot Jack Posted July 6, 2003 Author Share Posted July 6, 2003 Ok a couple fo questions.. Emkay -- are there any MCS tools? That is a great hires picture BTW -- thanks for posting it. Does anyone know where to get GED display routines? Lord Chaos -- can u post the basic program to make that display, I kinda get what u and bryede are explaining with GPRIOR... Thanks.. sTeVE Link to comment Share on other sites More sharing options...
Bryan Posted July 6, 2003 Share Posted July 6, 2003 to reach the color depth of a c64 you'd need 3 new colors every 2 cpu cycles. So, Frohn's our resident heckler, right? -Bry Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Archived
This topic is now archived and is closed to further replies.