analmux Posted August 15, 2003 Share Posted August 15, 2003 A way to create better graphics, is a project I did in summer 2002. It consists of a double GTIA-ANTIC circuit. The second circuit has it's own 64kb DRAM, but can be accessed by a memory window in $D5xx, and a page select chip, for which I used Port A from a 6526 from a C64. Now I'm working on a triple GTIA-ANTIC board for 320*200 pixels / 64 color resolution. The principle is based on the GTIA-modes. The main GTIA only shows the colors, while the second GTIA shows only the luminances. The LUM-circuit of the first GTIA and the COLOR-circuit of the second GTIA are not used. In this way I displayed some wellknown TIP pictures ("ALTAR") without flickering and interlacing. ...but after all, you can't say it's an atari 8bit anymore..... -------------- analmux Quote Link to comment Share on other sites More sharing options...
Jetboot Jack Posted August 15, 2003 Share Posted August 15, 2003 Tell me more -- sounds AWESOME.... sTeVE Quote Link to comment Share on other sites More sharing options...
analmux Posted August 15, 2003 Author Share Posted August 15, 2003 Picture 1: Front side of my 2nd Antic-Gtia board. Picture 2/3: Some details Picture 4: Back side (with wire-spaghetti and capacitors) --------- A: 8 sockets for d-ram chips 4164 B: ANTIC socket C: GTIA socket D: 6526 socket E: 4bits Mux (multiplexers) for row/column address decoding and LUM select (between the 1st and 2nd GTIA) F: 7432 Hex Or Port for enable logic G: 7486 Hex XOr Port for enable logic H: 74243 4bits bus-transceivers for external memory access. Quote Link to comment Share on other sites More sharing options...
analmux Posted August 15, 2003 Author Share Posted August 15, 2003 Quote Link to comment Share on other sites More sharing options...
analmux Posted August 15, 2003 Author Share Posted August 15, 2003 In the design: Cyan is the frontside design Orange is the backside design. Purple is where they overlap. Red is just comments which didn't appear on the overhead sheets. The black circles are reference points, where I drilled small holes in the board, to be sure the front and back side coincide. This design wasn't bugfree, I needed to make some changes (with extra wires). Quote Link to comment Share on other sites More sharing options...
Shawn Jefferson Posted August 16, 2003 Share Posted August 16, 2003 Bob Woolley mentioned once in csa8 that he did a mod like this to add a second ANTIC with its own memory. It's cool, but the problem is that any software would have to be written specifically for it (right?) and the fact that not many people would make the mod themselves... Quote Link to comment Share on other sites More sharing options...
Jetboot Jack Posted August 16, 2003 Share Posted August 16, 2003 Yeah on teh one had that's true, but look at the C64 scene, there are accelerators et al for that system that ARE in use, with software to support them... How does this board interface with the 8bit, although doubt if it could be doen this way a PBI device that extends the system like this would be very accessbile to most users... An 8bit with extended audio (2 pokey say ) and extended ANTIC or GTIA functionality would be a very cool system indeed, maybe the natural evolution of the platform... I for one would be very keen to both invest in hardware upgrades like this and also evelop for them, it COULD be very exciting!! sTeVE Quote Link to comment Share on other sites More sharing options...
analmux Posted August 16, 2003 Author Share Posted August 16, 2003 Off course this is just a prototype. And a newer design could be much smaller. This card was connected with about 50 wires to the atari-board, but a new version can be designed to plug into a socket, although your atari must have (like mines) sockets for the GTIA and ANTIC. the 1st GTIA was mapped at D000-D07F and the 2nd GTIA was mapped at D080-D0FF the 2nd Antic was accessible at D5xx by memory window, when the page- select Port was on page 212 ($D4). Antic seems to map itself in $D4xx independent of the atari-memory mapper (74-138 on board) To make it smaller f.e. * the 4bits bustransceivers could be replaced by 8bits bustransceivers (so you would need less of them) * the RAM can be just static ram, which needs no row/column decoder (the ras/cas-decoding was the hardest part, then I found out that there is SRAM on the market) and is one big IC instead of 8 small ones. * the 6526 can be replaced by a 8bits latch. * the card can have pins in the backside, to connect them in the ANTIC/GTIA sockets on the atari-board (the antic has full address control, so the extension card is provided with them too) Problems: -$D5xx should be reserved for cartridge control $D1xx should be reserved for Harddisk control (possible place in memory: $D6xx or $D7xx) -You'd need to pull the extra GTIA / ANTIC from another atari (or some weirdo must have a barrel full of old GTIA's / ANTIC's) -Indeed software can be the main problem, but this board is very easy to program. -If there is someone out there like mr. 'classics' who'd like to make cards (without the IC's), and you'd only have to push the IC's (that you can buy in a local electronics shop) in the sockets on the card (except the ANTIC/GTIA), it could be a lot easier. Quote Link to comment Share on other sites More sharing options...
Albert Posted August 16, 2003 Share Posted August 16, 2003 Wow, that's pretty cool. Do you have any examples of graphics created with this setup? I'd love to see what's possible! ..Al Quote Link to comment Share on other sites More sharing options...
analmux Posted August 16, 2003 Author Share Posted August 16, 2003 These pictures show the TIP-principle (which work on normal ATARI): Picture 1 & 2 are the two frames of the ALTAR TIP-demo. The screen switches between the two frames every 1/50 or 1/60 second, to create the flickering/interlacing effect. This is needed because the gr. 11-lines between the normal high colored lines are dark. Only the colors from the gr. 11 lines are copied to the next rasterline, where it's logically ORed with the gr. 15 line with setcolors (0,0,4 1,0,8 2,0,12 4,0,0 for a 4 step gray-scale). In picture 3 you can see it in more detail Picture 4 shows what is possible on the double video circuit board, although this is a emulated picture. I can't make real screenshots, because I disconnected the extension board due to lack of space inside the atari. Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted August 16, 2003 Share Posted August 16, 2003 holy holy shit... mux... can you upgrade one of my 800xls with 2 pokeys and snd gfx unit???? how many € do you think will it cost? i have 2 XLs where you could pull antic,pokey,gtia out of one and set it into the 2nd one... maybe upgrade the RAM in same procedere to 1mb... how many € would you charge me if i send you the 2 XLs (niederlande is not far away from germany... ) hve Quote Link to comment Share on other sites More sharing options...
analmux Posted August 16, 2003 Author Share Posted August 16, 2003 holy holy shit... mux... can you upgrade one of my 800xls with 2 pokeys and snd gfx unit???? how many € do you think will it cost? i have 2 XLs where you could pull antic,pokey,gtia out of one and set it into the 2nd one... maybe upgrade the RAM in same procedere to 1mb... how many € would you charge me if i send you the 2 XLs (niederlande is not far away from germany... ) hve I don't know much about the double pokey or memory upgrade, but I think I can upgrade your gfx. costs of IC's estimate: 12 euro board print: 6 euro other electronic compontents (capacitors et al): 5 euro so the material would cost (estimated): 23 euro I'd have to check, I haven't been in my local electronics shop for a while. I also would have to redesign the board to make it fit inside the atari, it could use a lot of space, and it might get hot, when turned on for an hour. At the begin of september I have a lot of work to do at the university, so I'd have to make some time free. So, let me think a few days about it. I do not yet know what to ask for the upgrade job, and for how many people I will do this. ------------- mux Quote Link to comment Share on other sites More sharing options...
Thelen Posted August 16, 2003 Share Posted August 16, 2003 WOW !!! That's a very intresting project !!! and you get 4 extra players + missiles ?! Thelen Quote Link to comment Share on other sites More sharing options...
analmux Posted August 16, 2003 Author Share Posted August 16, 2003 WOW !!! That's a very intresting project !!! and you get 4 extra players + missiles ?! Thelen You have indeed 4 extra PM ... BUT because GTIA 1 shows only colors and GTIA 2 shows only luminances, so you must place players from GTIA 1 at the same positions as players from GTIA 2. But you can create more colorful players: when player 0 + 1 overlap to create a third color/lum. when the PM colors on GTIA 1 are: player 0: $30 --> red player 1: $80 --> blue overlap: $B0 --> green {{no luminances used, so they are 0}} and PM lums on GTIA 2 are: player 0: $04 --> dark player 1: $08 --> middle overlap: $0C --> light {{no colors used, so they are 0}} so you can have 9 colors/lums in this configuration. They are: $34,$38,$3C $84,$88,$8C $B4,$B8,$BC ----------------- ----------------- A smaller design of the board might fit in the right-back of the atari, when the metal screen is partially removed. There is room for a board with maximum size of 12 * 8 * 1.5 cm. (the prototype is 16 * 10 * 1.4 cm). The board might even be plugged into the basic-rom socket, for address access, and to minimize the number of wires that have to be soldered from the board to the atari main board. @ Jetboot Jack ("I for one would be very keen to both invest in hardware upgrades like this and also evelop for them, it COULD be very exciting!!") If you'd like to invest/develop, you're welcome, but what do you mean exactly? Can you find someone that would like to produce the boards? @ Heaven The video-upgrade will take quite a lot of space, so when you want to install extra ram and a second pokey, I think you should build the atari in another casing (maybe a PC tower or something like that), like I'm planning to do for my mega-atari (it just doesn't stop). My mega-atari (I'm building right now) will contain: -atari 800 xl mother board -2 extended GTIA/ANTIC boards, each with own 64 kb SRAM and own 6502 processor for faster graphics -8 SID boards, each with SID 6581, 64kb SRAM and 6510 CPU for sampling (at 22.5 kHz or a bit higher) (I have a working SID-board prototype) -1536 KB extended RAM (12 * 44256 ic's) -64 KB EPROM (27512) with harddisk operating system -harddisk (IDE) -CD-ROM (IDE) (optional: for playing movies/music on atari) ------ mux Quote Link to comment Share on other sites More sharing options...
Thelen Posted August 17, 2003 Share Posted August 17, 2003 -CD-ROM (IDE) (optional: for playing movies/music on atari) for playing Movies or music on the atari ? what do you mean by that ? That machine you're building sounds awesome, But will it stay compatible with the real 8 bit stuff ? Thelen Quote Link to comment Share on other sites More sharing options...
emkay Posted August 17, 2003 Share Posted August 17, 2003 -64 KB EPROM (27512) with harddisk operating system -harddisk (IDE) -CD-ROM (IDE) (optional: for playing movies/music on atari) By this : I ever dreamed of an active pageflipping Memorycontroller.... So Transfer-speeds for up 14MB/s are possible... Well 14MB/s are never needed but it assures allways enough speed for displaying graphics, playing digi-sounds and else by simple pageflipping. Actual controllers are able to "poll" in kb/s ranges Quote Link to comment Share on other sites More sharing options...
analmux Posted August 17, 2003 Author Share Posted August 17, 2003 for playing Movies or music on the atari ? what do you mean by that ? That machine you're building sounds awesome, But will it stay compatible with the real 8 bit stuff ? Thelen Well, you can burn a CD with a movie or 4bits digimusic in a format the atari can handle. It should also be possible to do this with only an IDE CDROM drive connected to the atari (you can make an IDE interface in a cartridge, mapped at $D5xx) without al the other stuff I mentioned. When you burn a string of frames in gr. 7 or gr. 9 format (or whatever) on a CD it must be possible. My machine will stay downwards compatible. It is still an Atari 800 xl. Only with extended functionality, mainly mapped at $D6xx and $D7xx that are not used by older programs @ emkay I'm not sure I understand what you mean by 14 MB/s. Is that the maximum CD-ROM speed? Because the IDE interface allows the CPU to read the CD-rom with LDA/STA instructions, far less is needed (at 100 kB/s). Quote Link to comment Share on other sites More sharing options...
emkay Posted August 17, 2003 Share Posted August 17, 2003 @ emkay I'm not sure I understand what you mean by 14 MB/s. Is that the maximum CD-ROM speed? Because the IDE interface allows the CPU to read the CD-rom with LDA/STA instructions, far less is needed (at 100 kB/s). Try to think about a revolving door... You stand on one side of it and on the other side is the person you want to talk with... You and the opposite are writing Letters, put them on the door and rotate it 180°. Then you can read, what your opposite wants... and your oppisite can read what you still want. Then both can do what the other wants, write a letter again and rotate the door 180° again. For the ATARI this would mean: The fastest way to get new Data with a SCSI/IDE-controller via pageflipping. At the end this would be fast enough to view animated Graphics in 160x240 resolution with a 128 color kernal and digisound... It would be fast enough, because the Kernal is changed the same time when the graphics are changed: In the VBI or mid screen by a simple Pageflipping command. Quote Link to comment Share on other sites More sharing options...
analmux Posted August 17, 2003 Author Share Posted August 17, 2003 Emkay, I still don't understand your idea. Off course I understand the principle of pageflipping, but I do not see how that applies in the context of CD-ROMs. When you use an IDE controller, you can only read byte for byte of a sector of data, for which you need lots of CPU-time. You then have to put the data somewhere in memory, and then by double buffering you can flip pages, but with 25 frames/second you can (at maximum) move 4000 bytes, so I don't understand where you got that 15 MB/second number. For 160*192 (*128 colors) you'd need a lot of time for colorchanging- kernels, so you can't reach the maximumspeed of 4000 bytes/frame. And you'd not have fullscreen, or the framerate must be lowered. ----- mux Quote Link to comment Share on other sites More sharing options...
analmux Posted August 17, 2003 Author Share Posted August 17, 2003 ...or do you mean that there are DMA controllers for atari, so you don't have to read the sector data (and store it in memory with CPU) at all, and you just need to tell the controller which sectors you want to read, and the data automatically appears in a memory window (f.e. $8000-$BFFF cartridge space)? That would be ideal ----- mux Quote Link to comment Share on other sites More sharing options...
emkay Posted August 17, 2003 Share Posted August 17, 2003 ...or do you mean that there are DMA controllers for atari, so you don'thave to read the sector data (and store it in memory with CPU) at all, and you just need to tell the controller which sectors you want to read, and the data automatically appears in a memory window (f.e. $8000-$BFFF cartridge space)? That would be ideal ----- mux You got it! Quote Link to comment Share on other sites More sharing options...
Dracon Posted August 18, 2003 Share Posted August 18, 2003 Hi all ! This is my first post at AtariAge Forum. Glad to see you use my old picture ("ALTAR") which I prepared for a gfx-competion on Polish Atari party in Orneta (1996 or 1997 year). I've been always searching for best possible atari gfx-mode that I could use to draw my fullscreen graphix. Thus I used many different graphics modes so far - XLP, GED, CIN, HIP, TIP..... And always it turned out that you eiter got many shades without many color or many colors without so many shades. Isn't it irritating, anyway? At best one can get many shades and colors but the screen resolution isn't so high as should be... I can show you what I mean if anyone ask. In this year I won another Atari 8-bit gfx-compo, but I'm rather not completely satisfied with what I obtained... My picture was in TIP mode by the way. It seems to be rather "capricious" gfx mode since my older fullscreens look better in NUMEN demo. So to sum all up and fit in this thread - I would be happy if Atarians were given a cool colorful gfx mode with decent resolution and NO flickering at all. Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted August 18, 2003 Share Posted August 18, 2003 Cze Dracon, my friend! welcome on board... would be glad if you stay here... and not dissappear... btw... check the atari 8bit forums for more gfx discussions... back to "medal of honor:frontline...." hve/taquart Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted August 18, 2003 Share Posted August 18, 2003 Cze Dracon, my friend! welcome on board... would be glad if you stay here... and not dissappear... btw... check the atari 8bit forums for more gfx discussions... back to "medal of honor:frontline...." hve/taquart Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted August 18, 2003 Share Posted August 18, 2003 Cze Dracon, my friend! welcome on board... would be glad if you stay here... and not dissappear... btw... check the atari 8bit forums for more gfx discussions... back to "medal of honor:frontline...." hve/taquart Quote 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
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.