supercat Posted January 10, 2006 Share Posted January 10, 2006 Well, I'd think that "many" colors probably was pretty easy to put in a chip. I could imagine though that for a computer like the C64 with its charmodes it'd create all sorts of "palette" management issues. 997100[/snapback] To get an adequate selection of colors in composite video, you need to be able to control luminance and chroma phase (hue). Controlling chroma amplitude as well is necessary to achieve a photorealistic graphics, but it's not as essential for computer games or similar applications. Using two bits for luminance might have been adequate, but barely. When used on a black and white television, a two-bit luma would have meant video consisted of black, white, and only two levels of gray. Further, on a color television, each hue would be available in shades 'murky', 'darkish', 'lightish', and 'washed out'. So Atari decided to use 3-bit luminance (nb: I'm in a way surprised they didn't use 3 bits for luma+sync, which would have left about 6 luma levels instead of . Using three bits for chroma might have been adequate, but I would guess Atari decided going to four wouldn't cost too much, so they did. From what I understand, the Atari is hardly unique in generating composite video using 3-bit luma and 4-bit chroma. I think the Commodore computers do so as well, internally, and I wouldn't be surprised if the video chip in the TI-99/4a and Colecovision does something similar. The other computers, however, have circuitry which maps a set of 15 or 16 colors into luma and chroma values via a fixed method. They do this because they allow independent programming of many on-screen item colors. Allowing the user to specify one of 256 colors for each of those spots would double up on the memory or register requirements as compared with specifying one of 16. Circuitry is required to map the user's 1-of-16 choice into a luma/chroma combination, but one such circuit will handle everything on the screen. To be sure, it would have been nice if Commodore or TI had made the 4-bit to 7/8-bit mapping programmable, but the hardware to handle that would have added some cost and complexity. IMHO, not enough to prevent it from being worth doing, but it wasn't my decision. The Atari 2600 has four 7-bit color registers. That's all. Adding circuitry to map a set of 16 colors to a 7-bit luma/chroma code would not have been particularly complicated, but since the color selection circuitry only needed four 7-bit latches and a 4x7 multiplexor, saving 12 bits worth of latches and 4x3 multiplexor wasn't worth the effort. BTW, the Commodore 64 designers seem to have had a phobia of latches. The SID chip uses 8-bit values internally for attack, decay, and release rates, but requires the user to program a 4-bit value which is then fed into a 16x8 lookup ROM. I know small ROMs are cheap, but is a 16x8 ROM really cheaper than a four-bit latch!? Quote Link to comment Share on other sites More sharing options...
+FujiSkunk Posted January 10, 2006 Share Posted January 10, 2006 (edited) I believe the story goes that... Absolutely nothing in that story is correct. Long story short: Atari had contracted Amiga Corp to design a 16-bit computer for them. Commodore bought Amiga. Atari then cobbled the ST together using off-the-shelf components. 997113[/snapback] Aha. I stand corrected. Who needs Google when you have Zylon®? Edited January 10, 2006 by skunkworx Quote Link to comment Share on other sites More sharing options...
djmips Posted January 12, 2006 Share Posted January 12, 2006 I believe the story goes that... Absolutely nothing in that story is correct. Long story short: Atari had contracted Amiga Corp to design a 16-bit computer for them. Commodore bought Amiga. Atari then cobbled the ST together using off-the-shelf components. 997113[/snapback] Right. And a few more interesting details, Amiga was founded by Larry Kaplan (Kaboom) and others, and got Jay Miner to come over from Zymos (pacemakers). And some not so interesting details :-) the ST, cobbled together as it was also did have a few rather boring custom chips, MMU, DMA, GLUE and later SHIFTER (bitblt unit). It was not based on the SEGA Genesis! (weird urban legend). I personally think that Jay Miner get's more credit than is deserved, especially with regard to the 2600, these systems are quite a group effort. Quote Link to comment Share on other sites More sharing options...
+Trebor Posted February 9, 2006 Share Posted February 9, 2006 (edited) Hi Eduardo, Hopefully, any more posts will stay on topic this time...lol. Still checking in...any updates with this port? -Trebor Edited February 9, 2006 by Trebor Quote Link to comment Share on other sites More sharing options...
128Kgames Posted February 15, 2006 Share Posted February 15, 2006 Eduardo- I know it's been a while since you updated us on this project; just wondering if it's still in "production" or if it's been abandoned? I see from your site that you're now working on a hardware project for the CV. Does this mean no new software projects are on the horizon? I hope this version of DK actually gets completed. Quote Link to comment Share on other sites More sharing options...
opcode Posted February 15, 2006 Author Share Posted February 15, 2006 Eduardo- I know it's been a while since you updated us on this project; just wondering if it's still in "production" or if it's been abandoned? I see from your site that you're now working on a hardware project for the CV. Does this mean no new software projects are on the horizon? I hope this version of DK actually gets completed. 1018775[/snapback] Hi, My website was hacked last year, some 5 months ago, and to be honest I haven't updated it since. However I am hoping to change this state of things this weekend, putting the game pages back online, including a page for the new Magical Tree. DK Arcade will get a page too. About software projects being abandoned, it is exactly the opposed: all hardware projects are on hold indefinitely, except for the MegaCart which is required for Pac-Man Collection and isn't being handled by myself. Truth is, probably I can serve better as a software guy than trying to be a all around CV techno god... Eduardo Quote Link to comment Share on other sites More sharing options...
Atariboy2600 Posted February 15, 2006 Share Posted February 15, 2006 Eduardo- I know it's been a while since you updated us on this project; just wondering if it's still in "production" or if it's been abandoned? I see from your site that you're now working on a hardware project for the CV. Does this mean no new software projects are on the horizon? I hope this version of DK actually gets completed. 1018775[/snapback] Hi, My website was hacked last year, some 5 months ago, and to be honest I haven't updated it since. However I am hoping to change this state of things this weekend, putting the game pages back online, including a page for the new Magical Tree. DK Arcade will get a page too. About software projects being abandoned, it is exactly the opposed: all hardware projects are on hold indefinitely, except for the MegaCart which is required for Pac-Man Collection and isn't being handled by myself. Truth is, probably I can serve better as a software guy than trying to be a all around CV techno god... Eduardo 1018813[/snapback] Hope your page gets fix soon, btw hows the Pac-Man label thing? Still in the making? Quote Link to comment Share on other sites More sharing options...
King_Salamon Posted March 30, 2006 Share Posted March 30, 2006 Donkey Kong done right would be great... often wished there was a complete version on the Coleco - because, after all, it certainly can handle it! Some thoughts... I liked the idea of game options 1 and 2 being the classic DK with all the levels and then perhaps game options 3 and 4 being some version with added levels etc. As for the comment someone raised about the absence of all 4 levels in a console game... there is one. DK64 for the N64 had an unlockable level where you would approach a DK cabinet and play the arcade version on Donkey Kong. It's a lot (too much really) of work to get to but it does exist. This version had all 4 levels but I'm not certain about the intermissions etc. Although I think it was an emulated arcade rom of the game (not sure of that though). Opcode - I agree on your take of the software/hardware situation... I know I will buy lots of your carts as they are released, and I know there are chances of several releases in a year (means more sales more interest), the hardware story... one shot and you have to hope it works out. Quote Link to comment Share on other sites More sharing options...
vdub_bobby Posted March 30, 2006 Share Posted March 30, 2006 As for the comment someone raised about the absence of all 4 levels in a console game... there is one. Make that two! Don't forget the XEGS! Quote Link to comment Share on other sites More sharing options...
King_Salamon Posted March 31, 2006 Share Posted March 31, 2006 Really? I didn't realize the XEGS had 4 levels... mind you I was a c64 gamer and didn't get an XEGS until they were clearing them out on the home shopping channel! I never did get much into the XEGS though as I had 100's of games on the c64 and all my buds had the same. Quote Link to comment Share on other sites More sharing options...
Gregory DG Posted March 31, 2006 Share Posted March 31, 2006 Really? I didn't realize the XEGS had 4 levels... It's actually the Atari 8-bit computer version (which of course works on the XEGS.) Here's my review of it with screenshots. Quote Link to comment Share on other sites More sharing options...
King_Salamon Posted April 1, 2006 Share Posted April 1, 2006 Nice review... although I gasped when I saw the thumbnail pic of the first stage... it looked all wavey... then I clicked on it and it was ok. LOL! Perhaps Opcode's version can obtain the 100% score that the XEGS version came so close to! Quote Link to comment Share on other sites More sharing options...
+Trebor Posted May 16, 2006 Share Posted May 16, 2006 Well...I know it has been 7 months since the original post, and 3 months since an update by Eduardo. However, I'm still hoping we will see this homebrew come to a completion. I still get excited seeing those 'preview' shots at the beginning of this thread, and I still have the MESS Coleco"memory expansion"Vision edition eagerly waiting for Donkey Kong Any news or updates with this port? -Trebor Quote Link to comment Share on other sites More sharing options...
doug0909 Posted May 17, 2006 Share Posted May 17, 2006 (edited) Why isn't anyone considering the versions of DK made for the Odyssey 1 (with TV overlays), Fairchild Channel F, and RCA Studio II? Just kidding... Edited May 17, 2006 by doug0909 Quote Link to comment Share on other sites More sharing options...
King_Salamon Posted May 18, 2006 Share Posted May 18, 2006 Opcode must be rather busy as I have emailed him a month or so ago and have not received a reply... his absence on here suggests he is busy with other matters. Hopefully he will bring some PacMan and Donkey Kong love to Coleco Fans! Quote Link to comment Share on other sites More sharing options...
Pixelboy Posted May 18, 2006 Share Posted May 18, 2006 Opcode must be rather busy as I have emailed him a month or so ago and have not received a reply... his absence on here suggests he is busy with other matters. Hopefully he will bring some PacMan and Donkey Kong love to Coleco Fans! The last time I heard from him, some time ago, he told me he was going to be on vacation from his job for the last three weeks of May, and that he was going to travel with his wife for at least two of those three weeks. I assume he'll be back to grace us with his presence eventually. As for the DK project, it's on ice until Eduardo gets other projects done, the first of which is Pac-Man Collection. I'm not sure what he plans to do after that, although I hope he will complete his work on the game engine prototype for the BasicVision project. Quote Link to comment Share on other sites More sharing options...
Cybergoth Posted May 18, 2006 Share Posted May 18, 2006 Ah, fine. I also experienced a communiactions breakdown with Eduardo. I hope he'll be back soon Quote Link to comment Share on other sites More sharing options...
King_Salamon Posted May 18, 2006 Share Posted May 18, 2006 Oh Opcode... how we miss thee! Hope you are having an excellent vacation! As for Pac-Man Collection.. it's looking amazing and here's to hoping DK follows Pac-Man! Quote Link to comment Share on other sites More sharing options...
NightSprinter Posted May 18, 2006 Share Posted May 18, 2006 I know. I actually want an MSX2 with SCC cartridge from what he's said about the MSX2 version. Quote Link to comment Share on other sites More sharing options...
+Trebor Posted August 11, 2006 Share Posted August 11, 2006 Hi Eduardo, Any progress on this better Donkey Kong port? I haven't forgotten about this one -Trebor Quote Link to comment Share on other sites More sharing options...
opcode Posted August 11, 2006 Author Share Posted August 11, 2006 Hi Eduardo, Any progress on this better Donkey Kong port? I haven't forgotten about this one -Trebor Pixelboy gave me a good advice: a game a time, so right now I am concentrating all my energy on Pac-Man Collection, a game which has been in making for years. As soon as it's fiinshed, which I hope will happen later this year, I will be free to resume DK Arcade. Anyway I had done some extra progress on the game and it's now displaying the ramps round. I had started to work on the enemy routines, and if I remember there are 11 enemies max in the ramps round. DK Arcade is top priority in my todo list, cause I am a big fan of that game and I know many CV users would love to play a better version of it (including myself). Besides, it's time to make clear once and for all which console has the best version of DK.... Eduardo Quote Link to comment Share on other sites More sharing options...
Pixelboy Posted August 11, 2006 Share Posted August 11, 2006 Pixelboy gave me a good advice: a game a time, so right now I am concentrating all my energy on Pac-Man Collection, a game which has been in making for years. As soon as it's finished, which I hope will happen later this year, I will be free to resume DK Arcade. I thought Arkanoid was going to be next on your list after PMC, but I'm fine with whatever you choose to do next. As for PMC, I'm pretty sure you won't have much time to do anything CV-related once your move to the US starts taking up all of your free time (we probably won't hear from you much between October and February, I'd expect), so you better work on putting PMC behind you (software-wise) before mid-september, even if you won't be able to release it on cartridge before March of next year. Focusing on PMC is really the best thing to do right now, even if stuff like Zanac, YAKF2 and DK Arcade are making everybody drool in anticipation. Anyway I had done some extra progress on the game and it's now displaying the ramps round. I had started to work on the enemy routines, and if I remember there are 11 enemies max in the ramps round. DK Arcade is top priority in my todo list, cause I am a big fan of that game and I know many CV users would love to play a better version of it (including myself). Besides, it's time to make clear once and for all which console has the best version of DK.... Couldn't have said it better myself. Quote Link to comment Share on other sites More sharing options...
opcode Posted August 11, 2006 Author Share Posted August 11, 2006 As for PMC, I'm pretty sure you won't have much time to do anything CV-related once your move to the US starts taking up all of your free time (we probably won't hear from you much between October and February, I'd expect), so you better work on putting PMC behind you (software-wise) before mid-september, even if you won't be able to release it on cartridge before March of next year. Focusing on PMC is really the best thing to do right now, even if stuff like Zanac, YAKF2 and DK Arcade are making everybody drool in anticipation. Let me tell you... Now life is funny, isn't it? I am expecting to have more free time once I move to the US. Not kidding. Perhaps not in the first few weeks, you know, as I will be busy buying stuff at Best Buys and Walmarts of life. But once I have my new home theater and videogame systems in place, I will be all retro gaming... Ah, finally I am going to the expos, meet people.... I can't imagine how lonely is the live of a classic gaming fan here... Too bad my videogame collection will stay in Brazil for a while. I am sure you would be impressed by the quantity and quality of my Atari items... Eduardo Quote Link to comment Share on other sites More sharing options...
Pixelboy Posted August 11, 2006 Share Posted August 11, 2006 Let me tell you... Now life is funny, isn't it? I am expecting to have more free time once I move to the US. Not kidding. Perhaps not in the first few weeks, you know, as I will be busy buying stuff at Best Buys and Walmarts of life. But once I have my new home theater and videogame systems in place, I will be all retro gaming... Ah, finally I am going to the expos, meet people.... I can't imagine how lonely is the live of a classic gaming fan here... Too bad my videogame collection will stay in Brazil for a while. I am sure you would be impressed by the quantity and quality of my Atari items... I hope your expectations in terms of extra free time will come true, Eduardo. (Personally, I wouldn't have those kinds of expectations if I was moving to another country, but that's just me.) Quote Link to comment Share on other sites More sharing options...
+Allan Posted August 11, 2006 Share Posted August 11, 2006 As for PMC, I'm pretty sure you won't have much time to do anything CV-related once your move to the US starts taking up all of your free time (we probably won't hear from you much between October and February, I'd expect), so you better work on putting PMC behind you (software-wise) before mid-september, even if you won't be able to release it on cartridge before March of next year. Focusing on PMC is really the best thing to do right now, even if stuff like Zanac, YAKF2 and DK Arcade are making everybody drool in anticipation. Let me tell you... Now life is funny, isn't it? I am expecting to have more free time once I move to the US. Not kidding. Perhaps not in the first few weeks, you know, as I will be busy buying stuff at Best Buys and Walmarts of life. But once I have my new home theater and videogame systems in place, I will be all retro gaming... Ah, finally I am going to the expos, meet people.... I can't imagine how lonely is the live of a classic gaming fan here... Too bad my videogame collection will stay in Brazil for a while. I am sure you would be impressed by the quantity and quality of my Atari items... Eduardo What part of the country are you moving to? Allan 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.