retrocon

It's likely I'll have some questions regarding the tia chip from time to time as I work on my project. I'll post all these questions on this one thread to keep things organized. Some of them may be dumb, simple, naive, whatever, but please bear with me. I'm going through all the docs I have, but still not all is clear yet. First question: Are any of the values of registers, memory, etc initialized on power-on or reset on an original 2600? Are they set to 0? Are they usually 0? Do programmers always initialize first or are they any known cases where game programmers make assumations about unknown values? Next question: Regarding the 6507 that the 2600 uses. Does it include the BCD functions? If so, is it known if any games much use of this functionality? I know the NES doesn't have the BCD stuff, so I haven't coded it yet. If it's not in the 6507 then I probably won't bother.

0 bytes left? Forget what I said then. This baby is ready to go then. That is some amazingly efficient code.

Please check my website from time to time. I will have plenty of updates there explaining each step I take as I progress through this project. Right now I'm just focused on two things. 1. Getting a complete 2600 SoC running on the simulator. 2. Once #1 is done, getting that SoC running properly on dev hardware.

All good questions, most of which I don't have answers to yet. At this point I am just worried about implementing a 100% compatible 2600 on an fpga. I can answer a couple questions though. I will try to control cost generally by putting everything possible into a single chip, creating as small a pcb as possible, using common off the shelf parts wherever possible and doing all the design and intellectual work myself. The price could end up being more than $50 but that is the price I'm shooting for right now. The price of components generally depend on the volume ordered, so the more preorders I get, the more safely I can plan to build a larger initial batch. You can buy $4 toasters at walmart and that has to reflect a nice profit for walmart as well. I don't know if you've ever purchased fireworks, but I have a relative in the business and those fireworks you might pay up to $20 for cost pennies to purchase from chinese factories. Fpga prices are becoming more reasonable. I am looking at xilinx, altera and actel and I will use the one that supplies the best price for the complete SoC. Just an example here: http://www.xilinx.com/prs_rls/silicon_spar...2s3_pricing.htm The vga controller will be built into the fpga. This is trivial compared to ntsc and there are several example vga controllers for vhdl you can find if you google for them. Part of the main purpose of this project is for me to master the various display formats. You seem very knowledgeable. Perhaps you could help with some of the other issues if you have already researched them?

I think everybody realizes this is just a friendly thread to get people's opinions and that those opinions really matter. Don't worry, since nobody seems interested in a tia+, I won't do it. I will have my hands full as it is with the tia.

I don't know if it would be unfair, but I'd like to try it maybe as an advanced option. It might be fair if you didn't put it too close to any other barrier. How many bytes have you got to spare? i think you can do this mod in 13..no 12 bytes...hehe

I have always been one of those kids that always wanted to do something when the teacher said I shouldn't so now I can't stop thinking about a tia+ What would you think of this feature: A high-resolution (non-interactive) background screen composed of chars that would only change maybe once per level (and would be setup before the kernel executes). Basically the frames composed from the kernel would be blitted onto this background on the tia+, otherwise on a tia you just won't see the background. This would be kinda like the odyssey 2/3 enhancement if you are familiar with that console? Some games could almost be arcade perfect with this feature. Imagine an arcade perfect pac-man background for instance? What do you guys think about this?

I love this game. Would it be possible to allow some of the barriers to move at a random speed vertically? It would fun trying to time and dodge their movements.

I would think that might not be the case if the changes I made all reflect the wishes and ideas of the homebrew authors. In that case it is almost like a new atari is being built based on your experiences with the console. That is an exciting idea. I'm sure each programmer could come up with a tweak or two here or there that would have made his game better but just wasn't possible because of the existing hardware. These are things that wouldn't change the challenge or complexity of writing the games, but would open up a few new possibilities. Adding ram was not really something I was thinking of: a 2600 with a gigabyte of ram is probably no more fun to write for than a pc. I really like the ram limitations because is a major factor in the experience of developing games for the system. Now that being said, the SC functionality might be fun to implement some time if there is demand there.

I see that some people are upset about the idea of creating a tweaked tia+. I don't really see the problem with it myself. It won't harm the 2600 fan base in any way or split the community. Look at how strong this community is and the console was released 25 years ago or so. If it can survive and prosper after this long, it will survive anything. Any activity that involves the system is good. Whether that be creating new homebrew games, creating new hardware or hardware modifications, repairing systems, writing technical documents, posting articles on this forum or even just playing the games. It is all good. It brings people together and gives them new and exciting things to think about and toy with. It keeps the dream alive! Plus I think we are talking about a few tweaks here. If you trick out your corolla with a chrome V8 and a spoiler, its still a toyota and not suddenly a ferrari Imagine how cool it would be to just add in a couple things to the tia and suddenly open up some new and exciting possibilities. Even if the homebrewers don't use these features, it gives the hardware oriented guys something to dream about and play with. Maybe a few demos will come out to show off what could have been. Seems like harmless fun for those lusting to get under the hood....

You are number #26 on the list.

As the project got started I was unsure of which console to emulate first. I knew it had to be a 6502 console since that was the first chip I was building, but I finally realized that it makes more sense to build a 2600 before the NES because the former is the mother of all game systems and what I learn from it will prepare me to build its children. Yep, of course. There will be other versions too with different features if you don't like the first as well. I am putting everyone whom has requested either via thread or via PM on the list. I am kinda a loner and I kinda like to do everything myself. Not sure how well this would work. The short answer is no, not yet. I'm still thinking about it. I want it to be compact, yet have a retro feel and also not feel cheap. I don't really want to use cheap plastic; I want the case to represent the hardware well. I want it to look and feel like something I would be proud to own and show off. The 6-switcher is a puzzle. not sure yet, it will be fun though. I may need other switchs too. I want it to support NTSC/PAL/SECAM so things like this may end up being switches too. How about a DIP switch (get out your #2's!) Yep, you got it exactly. I can build off the functionality of the first one. Thomas, I just love the game Cave1k that you did. It is really fun and addictive. I think I am going to make a special 6502 instruction named after you, maybe THJ, but what should it do? Andrew Davie should get one too since I'm learning so much from his tutorial (but AND is taken ). Think he mentioned that he wanted a INA instruction. It's so trivial I can't believe they didn't put one in. Cybergoth I'll take you up on that. Hell I will probably be asking you many questions just to get the original tia going. Looking at the hardware manual, it looks like it will be quite a challenge reproducing it. Well, it will use a reprogrammable chip and I may if possible but maybe not in the first version put in a jtag interface so the hardware can be completely reprogrammed via your computer. Think of it as one minute having atari 2600 hardware and the next minute having colecovision hardware. This will probably come later. This will definitely happen, but I'm not going to attempt this until I have a few cart based systems under my belt. AC connector is likely. I hope I don't electrocute myself though! Save-state is a great idea that probably won't happen for a few revisions of the console. I like the idea of the cart inserting into one recessed end of the console so it takes up no additional space, kinda like the way the gpa sp carts are inserted flush with the system. We'll see though what is possible though because casing is not something I know much about. Ok, now I have to go crawl back in my hole and get back to work. Will post updates soon! Thanks for your support!

Does anybody out there have the "TIA Hardware Manual" that is referred to in the Stella Programmer's Guide? When I googled for it, there was a thread that indicated a pdf version exists, but the link is no longer good. If anybody happens to know a link or maybe has this sitting on their harddrive it would be most useful to me! Thanks. EDIT: I found it at this great site: http://www.whimsey.com/atari_docs/

This is pretty much exactly how I see this edition coming out. The expansion slot is something I'll take under consideration. I'm not sure I'll sell enough of these realistically to expect a thriving aftermarket of expansions Yeah also, I forgot to mention this but since the 2600 only has 128 bytes of ram (just AMAZING btw), there will be lots of unused ram left in the fpga for built in games. So I was thinking I might have one or more homebrew games built into the system (the game or a menu would automatically start when the console was turned on with no cartridge inserted). This is entirely dependent on being able to obtain the right to do so from the homebrew authors so I didn't want to stress it at this point.

I promise I will plaster the ether with pictures as soon as I get it to that stage. To Joe Stella: I know what you mean. But I just have to build this thing. Thanks everyone for your great responses! You are really motivating me to get this thing done. I feared that no one would be interested in this for the same reasons joe suggested. But I'm glad many of you are! I think it will end up being a great product and a great personal challenge to me which is the most important thing.

Sorry it is confusing because I have not revised all the web pages yet, but the console you are describing above is a different version of the retro console that won't come out for several iterations. Here is where you can see more details about the Atari 2600 edition: http://www.retroconsole.com/tiki/tiki-inde...st+Project+Plan This version will not have a compact flash. You will plug carts into it. It will have standard atari joystick ports (or more modern ports like psx if there is interest in that). Again, sorry for the confusion.

Hi guys, I wanted to get some feedback on a project I'm working on. Before I tell you about the project, let me tell you that I'm doing this for a love of retro-gaming, not for profit. I can still recall how excited I was when I walked over to the magazine rack of a local pharmacy and found Issue #1 of Electronic Games magazine. I think I was eight or so at the time, and that's exactly when my love of video games started. It has stayed with me my whole life. My hobby turned into a career after college when I got a job as a video game programmer. Now the cycle starts again. I just got my 6 year old nephew hooked on them as well And now I'm feeling some powerful nostalgia for those good old days of gaming fun when everything was so new and exciting. Ok, anyway, here is the deal. I am developing a new 2600 console. I am building a 6502/7, TIA and RIOT in VHDL so the entire 2600 system will exist on a single FPGA chip. At this point I am about 75% done with the 6502 and am starting research for the TIA chip. So here is a description of the system: - Tiny system (fits in pocket) - about the size of a couple of cartridges - Battery powered - Standard cartridge slot supports all 2600 game cartridges - NTSC/PAL/SECAM SUPPORT - Has following display ports: standard A/V, S-VIDEO, VGA - Has mono or enhanced stereo sound - Standard atari joystick ports or other maybe psx? - High quality non-plastic casing Other features under consideration that probably would not be feasible: - Reprogramability of fpga chip (so console can be updated with new version of hardware) - would require a parallel or serial port and support hardware - Turbo mode - 2600 running at 10x speed! - Enhanced TIA+. The mind boggles at the possibilities. - A handheld version with a built in display and gamepad may be developed in the future, but this version is a standard tv based console. The price point will hopefully be under $50 but not sure yet. I am hoping to build 100 systems initially and sell them to early adopters. How does this sound to you? Would you be interested in such a system? Any other feedback? Please check out the development website for more details: http://www.retroconsole.com Thanks!