Vinnie D.

Further thoughts. I have added a fan to my C64 in the past, but it's a very tiny fan drawing a fraction of an amp, and is exclusively for the VIC II chip (as the C64 is notoriously poorly designed in terms of heat dissipation), and it operates without issue. That however is a much smaller fan than I was thinking of for this project. I can see where this could be an issue with a larger one. Well, unlike the C64, as I mentioned before the Coco is pretty generous in terms of the sizes of its vents, and interior space, so maybe a fan isn't right for it after all. From what I've read, only the coco 3 really had overheating issues. I am pretty new to the Coco (more of a C64 guy really, and back in the 80's and 90's it was all IBM compatible PCs for me). So if a fan is a poor choice for the Coco, perhaps some passive cooling would be in order. I've already put a big fanned out heat sink on the CPU. Are there any other chips or components that it would be wise to heat sink?

Not long ago I picked up a Coco 2 on ebay on the cheap, and thought I'd start exploring its library and hardware. Given how the Coco series has the power supply inside the case, I noticed it gets pretty hot. I've already heat sinked the CPU, but that power supply is still putting out a lot of extra heat next to the motherboard that typical machines with external power supplies don't have to deal with. Given how generous the vent holes are, and how much space is open inside the case I believe I could add an 80mm fan to help dissipate some of that heat. That said, I'm having some difficulty finding much documentation on what is where on the motherboard. I need to find 5vDC that's easy to draw from, and that hopefully won't be missed if there's a little extra draw there. Any suggestions? While I'm at it, what other ICs could benefit from heat sinks?

A lot of older systems like the 2600 use these "RF" cables. Internally they're like less shielded coaxial cable (and carry the same signal), but the ends look more like RCA cables. I find the best way to get one is to just search "Atari RF cable" on ebay. You'll usually find them there with an adapter included. This should do what you need. https://www.ebay.com/itm/6FT-Video-Cable-RCA-RF-TV-Connector-Atari-2600-7800-Colecovision-Intellivision/391913294837?hash=item5b3fda4bf5:g:2~IAAOSw-xVZ8OYN You can also do away with the switchbox if it came with one. This will screw straight into the cable/antenna input on the back of your TV.

I'd certainly be interested in buying one if the price stays reasonable. I know economics of scale will be a challenge there, but I think looking outside of Atari Age for a wider market might bring in enough interest. I see plenty of benefit for a compact RS232 port that's compatible with older software, and isn't nearly as space consuming as the old sidecar or a PEB. In fact a more accessible serial port could open up chances for developers to create more applications for TI-99 users for communication with PCs, modems, and other peripherals. Certainly worth the space savings if nothing else.

Ok, I want to say big thanks to everyone who replied. I got way more information than I ever expected, and it looks like this started some great discussions. Looking at the options there's issues with all of them. PEB: I don't want one. Too big for adding one lousy port when I already have RAM, speech synth, and flash cart without one. Also much too expensive. Sidecar: Very hard to find, also expensive Nano PEB: Still kind of expensive, redundant with other things I already have, incompatible with most existing RS232 communication software, so no hooking a modem up to it. Joy Talk: This is fascinating and affordable, but is entirely software driven, and it doesn't seem to have caught on, so again incompatible with existing software. So the main reason I wanted an RS232 port is another project I'm working on. I found this http://subethasoftware.com/2018/02/01/wifi-coco-for-15-or-for-any-retro-computer-with-an-rs-232-port/and thought, with a simple adapter this could easily be a universal wifi modem for any vintage computer, which the computer its self would see as a simple hayes modem, much the way the fairly common wifi modems for the C64 do. The design of course is for the Coco (which I'll be working on later), but an SIO adapter should be fairly simple for the Atari 8-bit line as well, so I thought why not try to fill that role with the TI-99 as well. At the moment it looks like I've reached a brick wall. The PEB or sidecar are the only things that would have existing software applications. Of course there's the biggest obstacle which is (sorry to admit) I'm not that passionate about the TI-99. You see I'm most into the C64, though I love vintage tech in general. The TI-99/4a I learned about while reading up on the history of Commodore (and Jack Tramiel's personal mission to kill it), and when I stumbled across one on eBay for $10 I thought, why not. Though that's why I'm not really willing to drop $200 on a $10 machine. The accessories I do have, I largely bought because I caught them on the cheap. I found an Eastern European seller producing RAM expansions for below the standard price, I caught someone selling out their old stock of flashrom99 carts and got one on the cheap, and lowballed auctions for the speech synth until one went through. Yes I'm sorry to admit I'm a cheap bastard when it comes to the TI-99, but I still find it to be an interesting bit of computing history, and again thanks to all you much more passionate folks for all the info. Anyway, back on topic. I've reached the conclusion for the time being my TI-99/4A will be a gaming system with no external connections, but I'll keep a look out for a sidecar, or updates to the nanoPEB that would improve compatibility.

I've noticed one big critical flaw in the TI-99 and that's the lack of any form of serial cable. This means that aside from the cassette port, anything you want to attach absolutely must go through the sidecar. Now of course there's the PEB, and the RS232 sidecar unit. One is incredibly bulky and expensive, the other is hard to find and expensive. So I thought to myself, if the sidecar memory expansion can be brought down into a tiny little board that you barely notice, when the original was quite massive, why couldn't an RS232 serial interface be made to do the same? Has anyone done this yet? How difficult would it be to build such an interface for the TI-99/4A's sidecar expansion? Ideally I'd like to include a passthrough as well so that it doesn't terminate the chain (as my RAM expansion already does that). Any suggestions?

It's just "The Atari" unless I need to be more specific, such as if talking about multiple Atari consoles, then it's the 2600.

Sure, why not. I was 3 when I played Atari for the first time. Centipede is still one of my all time favorites.

Thanks. Looks like I'm off to ebay to grab an Extended BASIC cart then. This proved quite surprising since other retro computers can easily find added RAM through BASIC (except the C64 which already has all the RAM it can possibly address), so this weird sidecar style of expansion the TI-99/4A uses caught me off guard.

I'll preface this by saying I don't own a ZX Spectrum, but I have been looking into one some time in the future. If you don't mind giving up the authentic CRT experience, many modern TVs can swap between NTSC and PAL, and some even do it automatically depending on the signal.

You could just cheat, slap an extra CPU and RAM in the cartridge, and use them to implement a frame buffer entirely in software to bypass the "racing the beam" issue I suppose, then have the results output in a form the 2600 can understand, making it little more than a handler for what amounts to a console in a cartridge. It's not unlike what Nintendo did with the Super FX chip to make Starfox possible on the SNES. Even then you're still going to be held back by what the console is capable of displaying in both cases.

Recently my 32k sidecar expansion arrived for my TI-99/4a. I quickly discovered though that it's inaccessible via BASIC, and it'll be a while before I invest in a disk emulator or final GROM to load any 32k software. I do however have cables and a tape recorder for machines that load cassettes that way. Still as far as I know, most cassette software for the TI-99 are text adventures, and companions to cartridges like Adventure, nothing that was written to take advantage of the 32k sidecar. I really just want to test this thing to make sure it's in proper working order. Any software will do. Is there a tape version available of extended BASIC or Terminal Emulator II? Assembly? Any game that needs that much RAM? Ideally in wav format to cut down on the hassle of converting first, but I'll take what I can get.

If we're talking classic era games and not homebrew. Solaris: had a huge game area, some very impressive visuals, and different gameplay mechanics going on. A very advanced game. Pitfall II: included a more open exploration style of gameplay made possible with custom chips. Jungle Hunt: actually had paralax scrolling, something that wouldn't be commonplace until the SNES. Double Dragon: has horrible gameplay, but the fact that it even exists is impressive. It's far longer than most Atari 2600 games, features backgrounds where most games would just use flat black, can support multiple sprites on the same line, and has background music while most 2600 games just have a short pre game jingle. Too bad it's nearly impossible to play due to terrible controls. Battlezone: Sure it may not be the 3D vectors of the arcade, but it does a very good job of using what the 2600 can do to simulate the feel of 3D and display some impressive looking tanks and backgrounds.

In spite of finding some disassembly tutorials, and various suggestions for dealing with the rubber problem, nothing worked. I've tried sanding, belt grip, rubber bands, rebelting, cleaning, and it actually seems to have made things worse. All attempts at reconditioning the rubber that was present only made it more slick. I could find no workable substitutes for the lost rubber. Meanwhile the fast forward wheel completely snapped off. I give up. I've fixed tape drives before. In most cases a simple new belt and head alignment gets it back in shape, but this thing is a nightmare of horrible design. Honestly I'm not even sure if a working 410 drive even exists anymore. The playing mechanism is just too reliant upon UN-serviceable rubber parts. I declare this thing dead. The only thing I could imagine would be to replace the entire playing mechanism, and solder the main board to something better designed, and as that's a gigantic hassle, I am seriously considering just gutting the entire thing for an SIO2SD case later.

Raiders of the Lost Ark. Most people complained that it was confusing, but once you understood the controls there was fun to be had in discovering what to use where. Clever idea using the 2nd joystick to get around the button limitation.

1. Centipede: One of my all time favorite Atari games, and Hell one of my all time favorite games period. The 2600 port may not have great graphics, but it perfectly captured all of the gameplay elements. Not like you see details when you go into Atari zen mode anyway. 2. Phoenix: I've been playing this one since I was a toddler. The progression through different enemy types concluding in a battle against a boss enemy was satisfying and made it much different from Space Invaders. 3. River Raid: Not much to say here, it's just fun to blow stuff up. 4. Jungle Hunt: It was a tough call between this one and Pitfall, but Jungle Hunt won. When most games said that horizontal scrolling on Atari was too hard to do, this one did it, and did it with Paralax to boot. You either love or hate Jungle Hunt, but I love it. 5. Super Break Out: Assuming paddle games are allowed, this one's a must. 6. Super Princess Rescue: I may be cheating a bit here with homebrew, but why not include a great one if I can? Donkey Kong almost made the list, but this one pushed it out. 7. Solaris: A game that really pushes the 2600 to its limits. 8. Adventure: Never did finish that one. Guess I'll have time now. 9. Pole Position: I'm not that big on racing games, but sometimes I feel an itch and Pole Position scratches it. 10. Berzerk: Yeah can't think of any reason not to include this one.

It looks to be the newer version.

I don't think I was clear enough. We're well beyond the software stage of things here. This is a mechanical issue. When I attempt to load from tape the motor spins turning the main belt, but beyond that nothing else can happen, because all of the rubber is worn out and no movement can be transferred from there. Whether you call them tire wheels, idlers, or rubber wheels, the rubber parts are worn out, slick, deformed, and/or just plain missing. Because of this nothing can move. What I'm looking for is a solution to repair the actual mechanism that turns the tape, or replace it with one that works.

My Atari 400 happened to come with a free 410 tape drive. Unfortunately said tape drive does not work. I've successfully repaired Commodore 64 datasette drives before, so I thought this would be a simple matter of putting in new belts. Sadly that was not the case. I ask myself who designed this thing? It takes driving 3 rubber idler wheels (where a reasonable design would just use belts or gears) to transfer energy to actually turn the tape. These idler wheels have worn slick, cracked, deformed, or in some cases entirely fallen off. I've searched the forums and done what I can. I've replaced the belts, roughed up the surviving wheels, and applied belt dressing. My cumulative efforts got rewind, but not play working, and the fast forward has totally deformed. So I am left with 2 options. Replace all of the rubber wheels in this thing, in which case I'd need some very specific parts, and an affordable source for them. Or I could do something more drastic, and use the entire tape playing mechanism from another tape drive, and just keep the main board. The latter of those presents its own challenge, as I'd have to find something that would fit in the same case, and have the same button arrangement, or alternately just put the electronics of the 410 entirely into another tape drive. The C64's datasette is a good candidate. It's plentiful. It's inexpensive. The mechanism is durable, simple, and easy to repair, and I'm fairly sure I could just solder this board into it, or at most attach the read and write heads. Of course the latter, while the easiest to do means I lose the original 410's snazzy retro case, which would be a shame since it's not so much the utility of tape loading I'm looking for (as there are far better options these days), but rather to restore an old piece of hardware.

Thanks. I might can hope that someone will develop software with your 52k RAM expansion in the future. Have you considered a storefront, or maybe selling more of these on ebay? Since the supply of vintage RAM expansions for the 400 seems to have dried up, I'm sure there are more Atari enthusiasts out there who'd like one of these. Anyway great add on, and thanks for using shipment tracking. That was a big help with the local post office screwed up.

Got mine installed today, and it boots up just fine. One question. Is there any reason not to just set the jumper to 52k? Does this cause compatibility issues? It's a bit of a hassle to get into the 400 to keep changing it.

I'd be interested in one of those 48k RAM cards for my 400. Are you still making them? I'm in the U.S. here.