atari2atari

One of the difficulty switches is used for a pause feature on Kool Aide Man. When the switch is in the pause position on startup, the game freezes on the title screen. If you flip the switch, the game should start normally. The difference that might appear on your console is the score display. On some consoles (like Thomas Chinese Jr.) the score digits overlap. This constantly triggers the collision detection which results in Kool Aide Man constantly bouncing back and forth in the top left corner of the screen. This makes the game unplayable. Ah-ha! I will check again to see if the difficulty switch was flipped one way or another. That must be what it was - - I always thought the "freezing" in this game was the incompatibility bug! Good to hear that it's the score display, I'll check it and let you know. On all (?) 2600 Jr. consoles (NTSC and PAL) that are made in China after late 1989 the signal timing in the TIA for the shifting pulses for the movable objects seems to be a little off from older versions of the TIA. Therefore when a game starts the shifting process in such a way that some of the shifting pulses happen during the visible part of the screen, the movable objects might be positioned slightly differently. This affects all PAL 7800 consoles too, BTW. Something similar seems to be going on in your "unicorn" console too. You can see tis in your Pitfall II video. The game doesn't do an HMOVE in every line, so not all lines start with an eight pixel blank. Pitfall II tries to hide it with displaying a black eight pixel wide copy of missile 1 in those lines where it doesn't do an HMOVE. On your 2600 these missiles are shifted one pixel to the right. If you run Pitfall II in Stella and disable missile 1 with ALT-V, you can see that there are gaps in exactly the same scanlines where the one pixel shifts are in your video. Other games worth testing for compatibility would be the starfield effect in Cosmic Ark, the tile screen in He-Man and the cobra head in G.I.Joe / Action Force. Thank you, sir! That is all VERY helpful and informative! I'll try those games and report back with compatibility. Regarding the other side conversations on STELLA compatibility and TIA revisions, it's all very interesting, too. It is strange to me that ATARI would be so short-sighted as to make revisions to the core of the ATARI 2600 system that broke the basic programming conventions that they initially had established! -a2a

Many Post Offices will not care, and you can benefit from the savings. However, other AA members have had mail opened, either by their local Post Office, or the destination Post Office, and then the shipment denied or held. As a result, I stopped shipping anything Media Mail to prevent possible problems! I agree, a real bummer . . . -a2a

Just as a note, the U.S. Postal Service explicitly disallows video games to qualify for media mail - - http://pe.usps.com/text/csr/PS-334.htm I wish it were not so, but unfortunately it is. Maybe they will rule different in the future . . -a2a Edit: more detailed information is available here, too - - http://pe.usps.gov/text/dmm300/173.htm#1113500

I just did - - no go! KOOL AID MAN on the native cartridge does not boot! Well, it does, but it just freezes on the opening title screen. Hmm, noted! I'd be interested in knowing more about your Chinese PAL Jr.! No, that is not the only requirement, there is additional wiring needed to accommodate a 4k ROM in a Light or Heavy Sixer, but I am still figuring it out, so I could not tell you yet! It's a project in process, and yes, I will be posting up my results and asking for help with installing games in the Light Sixer "as it was designed" ! I think I will get some time this weekend to share with everyone where I am at with it . . . but here's some pictures to tantalize you! Coming along nicely! This is, of course, building on the work of others - - http://www.atariage....ost__p__1301781 http://www.atariage....rd-differences/ However, both of those projects/discussions got VERY close or hinted at solutions . . . and then never finished and/or documented clearly what they did! -a2a

You're welcome! Oh, by the way, Thomas, I did try popping in a cartridge while the on-board ROM was running, and as usual I got a bus contention and scrambled screen! Nothing interesting to report there . . . Well, I consider this thread "closed" and the question answered. Summary - - - The single-chip ATARI 2600 (aka ATARI 2100 "JAN") appears to (mis-)handle standard programming language for the 2600 - It is therefore incompatible with at least the HARMONY cartridge and there are some graphical glitches that have been observed with PITFALL II - Other game incompatibilities are not known yet, but it appears that anything that depends on HMOVE in a "creative" rather than "classical" manner can cause it - As an aside, if you want to know if your ATARI 2600 Jr might be a "unicorn," pop in the HARMONY cart or a copy of PITFALL II and watch for the graphical issues as reported in this thread and the video above! Thanks, everyone! -a2a

The music is the ‘bi bi ba tekkno remix’ of PITFALL II, from Remix.Kwed.Org, by arranger ‘chosc’ - - to find that tune, go to the Remix.Kwed.Org site, search for ‘pitfall’, and it should pop up. There is an option to download it on the right. Some of the other remixes are fun, too! A general search on the 'toobs for 'pitfall remix' will also reveal some VERY interesting projects, I found! Be careful where you click . . . -a2a

Take apart the carts, desolder and remove all the ROMs . . . . . . and produce BANKZILLA !!! See http://kevtris.org/2600/bankzilla.html for details . . . I just stumbled upon this monster, and am fascinated by it . . . -a2a

Yup, the old plastic gets very brittle on some of them, leading to spontaneous shattering! Luckily, the newer Jrs. seem to have better plastic? I was having issues with the "short rainbow" Jrs., but the "long rainbow" ones are mostly okay, except for the annoyance of those pesky tabs that hold the top and bottom shell together . . . hate those! Now that we know the graphical "glitches" to watch for on certain cartridges with these single-chip units, though, with the HARMONY and PITFALL II, for example, no one needs to crack 'em open . . . unless they like to tinker, like me! -a2a

And LittleJoe - - http://www.atariage.com/forums/topic/196368-unicorn-boards-and-harmony-cart-menus-single-chip-2600-compatibility/page__view__findpost__p__2498702 And, AtariJoe - - http://www.atariage.com/forums/topic/180077-atari-2600jr-unicorn/page__view__findpost__p__2261133 I'd say they are more common than we know, it's just that most folks don't crack 'em open and find out! The ability to build-in a 4k or 2k mask ROM, however, makes these VERY cool! The one I just did up with PITFALL built in is a lot of fun! -a2a

Or, just open it up and find out! Alternately, run PITFALL II on it, and see if you get the same issues with pixels on the left-hand side of the screen that I observed here, and then you will know if it is a "unicorn" or not - - Unicorn Boards and Harmony Cart Menus - Single-chip 2600 Compatibility? - Post #11 That thread post has the following this video in it - - -a2a

Maybe the 'Marketplace' forum? You might generate some interest there . . . -a2a

long rainbow X 11A4 304699 Atari Corporation Made In China PAL-B I'm thinking not a unicorn, based on that serial number, from this thread, "Atari 2600jr Unicorn", (that you were also participating in, I note) - - Is there anything external that identifies it as being single chip? Nothing definitive but it seems like serial number that begins with A19 are those made in 1990's and would have a single chip board. But, it's always worth cracking it open and taking a look! Or, at least, that's my philosophy as a hardware guy! -a2a

Probably not a unicorn, no, however I've been working with one of these "unicorn boards" recently (see this thread, "Unicorn Boards and Harmony Cart Menus - Single-chip 2600 Compatibility?," for some discussion on it) and also examined and opened quite a few Atari 2600 Jrs. looking for more "unicorns. " I don't think that the "waffle type" PCB is always a clear indicator. The best way to know is to open her up and take a look! Out of curiosity, what is the serial number on the bottom? That can also be an indicator, or at least help us to date your Junior . . . -a2a

You know what I need? I need a REAL video capture card, not a FLIP camera! You'd think a professional IT guy would have a few video capture cards around, but apparently it's all just OUTPUT cards . . . I'll add it to the list. Anyways, APOLOGIES in advance - - it is, well, just like filming a TV with a hand-held camera. I added an excellent (or annoying, depending on your view) remix of the PITFALL II music to entertain you. Note the extra pixel action on the left-hand side of the screen - - I zoom into it a few times for detail. And then compare it to the LACK of extra pixels on a standard four-switch (also video modded for composite output) http://youtu.be/t1oiDT9SKMQ I think I will re-record this when I get a better capture card and try to redeem myself . . . -a2a

Here's a post that might interest you, and actually be of use - - nice MOTHER 3 repros on NintendoAge! http://nintendoage.com/forum/messageview.cfm?catid=6&threadid=67548 Looks like the initial run is done, however, and so now it's a secondary interest list? If you can't wait, these are the two best, CURRENT sources for the EZ Flash IV, which in my opinion is the best GBA flash cart out there for the money - - http://r4-3.com/ezflash-iv-mini-gba-card-ez4-for-nintendo-gba-ds-ds-lite-p-19.html http://www.r4ds-ds.com/products/EZ-Flash-iV-mini-GBA-Card-For-GBA-gameboy-advance-sp-p-239.html Some also like this unit, but I have no personal experience - - http://www.ps2cover.com/products/Supercard-SD.html#reviews Hope that helps! -a2a

Some homebrews (e.g. Halo) use early HMOVEs to avoid the HMOVE blanks showing up. For Harmony, I suppose an early HMOVE which ends at cycle 74 is the problem. Ah, thank you, Thomas! I will try out HALO 2600 and see if I can get the same "staggering pixel" effect. I am curious to see what all the compatibility issues with these single-chip ATARI 2600 units are, such as different games! It would be interesting if Atari had inadvertently designed a single-chip solution that did not support ALL of the known programming functions! I will say that I have observed some VERY interesting behaviour on the left-hand side of the screen in the "HMOVE zone" (my personal term for it, probably inappropriate) during games of PITFALL II running off a native cartridge. I've never seen patterns like that before during a game of PITFALL II. The game plays just fine, but there is SOMETHING new going on there in the margin . . . ! Tonight when I am back at the house I will take some pictures or try and do a video capture of the screen. -a2a

I will look into what's available for ROMs of dumpers - - it's a great suggestion! I was also considering a SYNTHCART ROM as a candidate, too. This project is part of a larger one for me that includes trying to install ROMs into light and heavy sixers, as well, using the installation location that was designed into the boards, but not used in the final production models. I may just keep this single-chip "unicorn" somewhat pristine, though, and not alter it much more than another switch to disable the on-board ROM and try to increase compatibility with other cartridge games. I'll likely try a dumper with a light sixer unit, however! The "trick" with a built-in ROM with a dumping program and this setup or any other built-in ROM setup would be finding a way to get the built-in ROM to read what was in the cartridge slot WITHOUT having a bus contention. It will take some work to determine how that would funtion. I confess that at first pass, I am not certain it is do-able. No need, there is a spot for it on the motherboard, or it could go direct to the required pin(s) on the EPROM I'm sure it isn't either, but in the name of experimentation I think it's worth doing at least once. I have not tried plugging in a cartridge while the on-board ROM is running, I should try it at least once. I'm sure it will just be the usual scrambled Atari 2600 screen, like pulling a cart out while the power is on, and no permanent damage to either the on-board or cartridge ROM typically happens. Don't worry, I won't hold you responsible if it catches on fire and explodes! However, I might try it first on the light sixer that I have with a built-in ROM installed in it, too! -a2a

Thanks for reading and responding, Pioneer! With the way the motherboard is wired, you can have either a 4k or a 2k ROM on-board. No bank-switched ROMs, as I understand. I am not certain what the specs are on a cart dumper ROM, such as how large it is. Also, if the ROM is not a general manufactured mask ROM, but an EPROM instead, which I suspect any dumper ROM would be, then you need to place an inverter into the circuit on the board so you can properly activate the EPROM - - EPROM integrated circuits are turned "on" in a different way than mask ROMs, which an inverter would accommodate. Right now, with the default factory wiring, the motherboard can only accommodate mask ROMs. I have not tried plugging in a cart while playing the on-board ROM - - I'll give it a go. I imagine that you just get bus contention, and have to restart. -a2a

Thanks, batari! That helps me to understand that at least it's not the nature of the pre-production HARMONY cart I am using, and probably lies in an issue with the nature of the single-chip. It also helps that it is not a bus contention issue with the installed on-board ROM. I guess that a bus contention would just simply result in a no-boot situation! I appreciate the insight - - good observation, it IS off by one pixel on each line as it descends! I wonder what other games are dependent on HMOVE in this manner, and would also distort? I'll keep you posted as I move forward. Next I need to design a switch to disable the on-board ROM to allow certain other games to boot. Classic sensitive carts like DECATHALON and SPACE SHUTTLE are a non-starter on this unit right now, due to bus contention with the installed game, I imagine. THANKS!! -a2a

Greetings, Atarians! Some tales from the workbench, and a request for assistance. First, the story and some background, and then the question(s). I recently modded a single-chip ATARI 2600 Junior to accommodate a built-in game ROM, as it was designed. Quite simply, if NO cartridge is placed in the console and it is turned on, the console plays the built-in game. These so-called "unicorn boards" have been covered in a few historical threads here on AtariAge - - http://www.atariage....2600jr-unicorn/ (2011, thread on compatibility with HARMONY cartridge) http://www.atariage....-unique-2600jr/ (2010, a general thread on the unicorn board) and, DigitalPress link to the schematics for the single-chip unit - - http://www.digitpres...s/index.htm#vcs (choose the Atari 2100 "JAN" single chip link in the list) Here's my shots from the before-after install. I also added a simple transistor/resistor video mod while I was in there (just mono, no stereo mod, because I didn't want to start pulling pins on the chip needed for AUD0 and AUD1 !) The motherboard, before adding the built-in ROM, but after installing the video mod Blank area of the board where the ROM was to be installed at the factory Detail of the board revision number I installed a 24-pin socket to receive the ROM I chose PITFALL! as my installed ROM, and placed it in ANOTHER machine-tooled 24-pin IC socket, which would allow me to stack IC sockets on the motherboard for some form of modularity, in case I wanted to swap installed games on the "unicorn." 4k ROMs are apparently the maximum that the board can take. (See the schematics at DigitalPress and the threads referenced above) I could think of NO better 4k ROM than PITFALL!, a brilliant use of every ounce of available space! Socketed in, and all ready to go! Buttoning it all up . . . I use some serious "strain relief" in my direct, "corded" video mods to prevent ANY chance of the cord getting pulled and wrecking the electronic work inside! And, it works! Brilliantly! It plays PITFALL! if there is no cartridge plugged in, and for SOME games, when you load a cartridge, it disables the on-board ROM and you can play the game! More on that compatibility later - - it's a GIANT topic, and one I also have questions on, and you'll see more posts soon in the general 2600 forum area, and questions on the light/heavy sixers with built-in games, too. There is still some work to be done in order to maximize compatibility, and wire in a "kill-switch" that disables the ROM totally to do so. You'll see this topic again, no doubt! This, however, is a HARMONY CARTRIDGE question. Still with me? So, I popped in my HARMONY cart, and despite what I had read about needing to short certain pins on the cartridge slot in order to get it to work, it DOES boot up. The menu is skewed, however, and not easily readable! I can navigate the menu, go to sub-menus, and actually even select and launch ROMs . . . but I can't really read what I am doing, and have to operate by memory! Once a game is launched, there is no more graphical distortion, and everything plays as expected, for at least the half a dozen games I tried from the illegible menu. Another possible clue to the answers, maybe - - I am using a HARMONY pre-production cart that I traded with another member to get - - The SPECIFIC question - - - What do I do to the motherboard in order to regain what is apparently a graphical issue with this HARMONY cart that I have (the pre-production one) as well as any other HARMONY cart (important!) Thanks for reading all of that, and I welcome any and all suggestions, questions, and ideas! -a2a

Very nice transparent yellow NIB Dreamcast case on eBay UK - - eBay Auction -- Item Number: 231bb5cb29 I would be interested, but I already have my blue transparent one for my Dreamcast, and am quite pleased with it. I wonder if this is the same guy who posted this nice video "mod log" of illuminating a yellow case? http://www.youtube.com/watch?v=TfNL0tOjqCQ The ending with the music is kinda funny . . . He's got some other good video logs, too - - check out his channel. The backlit Dreamcast VMU mod is one I have been wanting to do for a while . . . -a2a

That would be great! I have a few 2600 PAL consoles that I have tried various video mods on, and I always get black and white output. This will be a welcome update. You should post up in the "Marketplace" when your website goes live . . . -a2a