[AQUARIUS] Mattel Aquarius Multi-Cart

[the-topdog]

Ok, I wanted to make a separate thread for the multicart posts since the general Mattel Aquarius thread is starting to get pretty convoluted.

 

JayBird3rd has engineered an 8-in-1 multicart for the Mattel Aquarius, which is a pretty serious leap forward for the Aquarius community... this development means that not only can you play some of the hard to find or impossible to find titles on the original Aquarius hardware, but this also paves the way for homebrews... something the Aquarius community has been sadly lacking.

 

You can read about the multicart in that original thread http://www.atariage.com/forums/topic/157641-mattel-aquarius/page__view__findpost__p__1972067

 

If you have any comments or suggestions for Jay about the multicart, please post them here or PM him. I will post a review of the multi-cart here as soon as I play around with mine a bit.

[Cebus Capucinis]

When will they be for sale?

 

Obviously I am a guaranteed buyer.

[jaybird3rd]

Thanks for starting this thread, Erik. Here are some more pictures of my prototype in its natural habitat:

 

 

My apologies for cluttering the other thread with posts related to the multi-cart project. Here is the relevant information about this project from my earlier post, omitting those portions that are now obsolete:

 

I acquired my first Aquarius computer from the OP about two weeks ago. Being a newcomer to the Aquarius, the first thing I did was to look into the software that was released for the system, starting with the games. I noticed that the library was very small, and that several of the best games were hard or impossible to find on cartridge. I wanted to play these games on the real hardware, so I figured out how to retrofit the cartridges with EPROM copies of the games.

 

Once I did that, it wasn't a great leap to conclude that I could design a simple multi-cart, containing multiple cartridge images that would be selectable by the user with a bank of switches. The user would simply consult the chart on the cartridge label, set the switches to the left or right to correspond to the desired game or application, and turn on the computer! It's a very simple idea that has been done many times over the years with many different computers and consoles, but never (as far as I can tell) for the Aquarius.

 

My initial tests indicated that this idea would work, so I produced my first prototype (pictured above). I originally intended this to be only for my own use, and I didn't really think it was a big deal, but topdog was so enthusiastic about it that I made one for him, too. He convinced me to consider building more, so after thinking about it a bit, I decided to announce this project in order to gauge the interest of Aquarius owners. The response on AtariAge and elsewhere has been encouraging, so we're researching the available possibilities for making a limited production run of multi-carts for the Aquarius community.

[jaybird3rd]

When will they be for sale?

We're still working on finding the hardware needed to build a large enough batch of cartridges. My earlier post was intended as a kind of "pre-announcement" to gauge the Aquarius community's interest, but right now I don't have enough hardware on hand to build enough cartridges for everyone. I know my design works, and I hate to keep people waiting, but at the same time, I'm reluctant to start "officially" taking orders until I'm certain that I have a stable source of parts: I don't want to start taking people's money only to leave them waiting for weeks at a time while we scrape and scrounge for cartridge donors.

 

One of the unexpected challenges we've encountered is that, for a system that was only on the market for a short time, the Aquarius used a bizarre and confusing variety of cartridge hardware. In the brief time I've been taking apart Aquarius cartridges, I've found no fewer than five different cartridge board designs, not all of which can be re-used as multi-carts. In some cases, the same titles were manufactured with different boards, and there's no way to know which board was used without opening the cartridge and looking. Even the plastic cartridge shells are different, with changes to the internal layout to accommodate the different boards. In addition, Aquarius cartridges are much more scarce than 2600 or Intellivision cartridges, so it isn't always possible to find a suitable supply of donors, and we certainly don't want to use up the limited stock of Aquarius cartridges that are out there.

 

One option we are seriously considering is designing a new board that will fit inside Intellivision shells, which are much more common and will fit perfectly well into the Aquarius cartridge slot. They certainly won't look as nice as true Aquarius cartridges would have, which is a shame, but unfortunately it seems to be the best available option. Due to the tooling costs involved, the very limited demand, and their unusual design, getting new Aquarius shells manufactured is absolutely out of the question.

 

I'll post updates in this thread, and will let all of you know as soon as we're ready to start taking orders. Until we know exactly where we're going to get the hardware, we won't be ready to announce a final price, but we're going to work hard to keep it within the range that I announced in my earlier post: $55 plus shipping for a new multi-cart. In the meantime, if you're interested in getting one of your own, please post in this thread to let us know so we have some idea of how many cartridges we will need to make.

 

Thanks to everyone for your patience and your interest!

[Bill Loguidice]

So, what's the best way to get in on this? Express interest here or go to the Website?

[jaybird3rd]

So, what's the best way to get in on this? Express interest here or go to the Website?

Expressing interest here is the best way to let us know. This will help us get some idea of how many people are interested in ordering a cartridge. We'll keep track of everyone who posts in this thread (or who contacts me directly through the e-mail link in my user profile), and those people will get the first batch of cartridges when we finally get them ready.

[Rev]

put me down for one as well.

[+swlovinist]

Put me down for one. Totally interested.

[+cmart604]

I'm in for one as well. And now I have to get an Aquarius. I love finding a good excuse to go collect something else.

[TimsterAA]

I'd definitely be interested - depending on how soon they'd be available. I'm kinda low on fundage for the near future.

 

--Timster--

[gavvv]

i'd definitely be interested in one. be nice to try out the other games i've not been able to find.

 

gavv

[+MattelAquarius]

Who? Me interested?

 

[Rev]

how is this project coming along?

[jaybird3rd]

how is this project coming along?

I'm so sorry to keep everyone waiting; I've found myself very busy with work and other projects lately. I was going to post an update over the weekend, but I think I've postponed it too long already.

 

Over the last few weeks, I've thought over my options, and I think the best way to proceed will be to design a new cartridge circuit board for the existing Aquarius shells. Because of the scarcity of Aquarius cartridges, I toyed for a while with the idea of using Intellivision shells instead (as I mentioned earlier), but I just wasn't happy with the way it looked. Part of the charm of the Aquarius is the way the cartridges fit so seamlessly into the console, and using Intellivision cartridges would have violated that design philosophy.

 

So, I'm going to offer the multi-cart as a bare cartridge board, which can be used as-is or installed into one of the buyer's own cartridge shells if desired, just as Chad Schell does with the Cuttle Cart 3. We might be able to provide a limited number of shells (priced at a small premium) for buyers who want a complete cartridge, but that isn't set in stone yet. I'll need another week or two to finish the design, and after that, another two or three weeks to have a prototype manufactured. I'll then be able to give everyone a better idea of what the final board will cost, but I still anticipate being able to stay within my original ~$60 price range. In the process, I'm going to upgrade the design to a 16-in-1 cartridge, large enough to hold almost the entire Aquarius cartridge library. I'm also going to make the board compatible with standard 16K ROM chips, so they can also be used for ordinary cartridges (including, possibly, new Aquarius homebrew games!).

 

One of the decisions I have to make at this point is what to do with the four bank switches that will be required for a 16-in-1, and how to make them as convenient as possible for users who will be installing the boards inside their own shells. The dilemma is that, if I install the switches directly on the board (the most straightforward solution), they'll be hidden inside the shell and unreachable from the outside without opening the cartridge. On the other hand, mounting the switches in the shell (as I did with my prototypes) would mean designing an additional daughterboard for them, and requiring the user to drill switch holes and make other modifications to the shell. This would also be inconvenient, and more expensive. I'd like to get some feedback from all of you on this issue: I'm leaning toward simply installing the switches on the board, but what would your preference be, and can you think of an alternative that I'm overlooking?

 

So, that's the current status of the multi-cart project, and I greatly appreciate your patience and your continued interest. In the meantime, I've also been working on another (much simpler) upgrade idea for the Aquarius, which involves a possible remedy for one of the most serious limitations of the system: the lack of reprogrammable graphics. I'm putting the finishing touches on something that Aquarius users should find exciting and fun to experiment with, and I'll be writing more about that shortly.

[Bill Loguidice]

Honestly, if it keeps your time and effort down, and our costs down, I would be perfectly fine with you installing the switches in the most logical manner. It would then be our responsibility to cut a sufficient space in a cartridge shell to access them (or a removable door), assuming we don't just plug the board in as-is sans shell. The only alternative I could think of besides the options you described would be some type of menu program on the Aquarius itself, but that would probably require another redesign of the board to be able to do the switching automatically.

[coyo5050]

Opening the cart everytime you want to play a new game seems awkward. I dont mind paying a little more or whatever involved (perhaps its a premium/deluxe version with the shell) if it makes it more convenient. Convenient will make me more interested in playing. Ultimately I want this cart regardless of how it is decided to be built.

[jaybird3rd]

Honestly, if it keeps your time and effort down, and our costs down, I would be perfectly fine with you installing the switches in the most logical manner. It would then be our responsibility to cut a sufficient space in a cartridge shell to access them (or a removable door), assuming we don't just plug the board in as-is sans shell. The only alternative I could think of besides the options you described would be some type of menu program on the Aquarius itself, but that would probably require another redesign of the board to be able to do the switching automatically.

Believe me, I'd love to be able to create something as sophisticated as the Cuttle Cart 2 or Cuttle Cart 3, but something like that would be much more expensive (and, frankly, beyond my ability to design at present). The 16-in-1 idea seems sufficient for the very limited library of Aquarius cartridges that are out there, at least for now, and I agree with you: the most straightforward design may be the best one of all. I actually think it will be perfectly usable without a cartridge shell at all, although I'll try to make it as easy as possible to mount in a shell for users who are too concerned with aesthetics to have a bare circuit board sticking out of their computers.

[jaybird3rd]

Opening the cart everytime you want to play a new game seems awkward. I dont mind paying a little more or whatever involved (perhaps its a premium/deluxe version with the shell) if it makes it more convenient. Convenient will make me more interested in playing. Ultimately I want this cart regardless of how it is decided to be built.

I agree; that's one reason I'm so glad that we might have the ability to offer completely assembled cartridges. Not everybody is comfortable with the idea of taking a Dremel tool to their cartridge shells, but even for those users who choose to go that route, I'm going to try to position the switches in such a way as to make the modifications as painless as possible (although the unusual shape of the Aquarius cartridges has made that surprisingly difficult).

[GroovyBee]

I know nothing about the development tools for the Aquarius or the signals available on the cart connector but how about a purely software solution? You'd have a boot ROM that copied itself to RAM for execution. It would then present a menu and then you could select the ROM to bank in and execute it. You'd just need a latch and obviously you'd also lose a "slot" in the cart for the boot code.

[jaybird3rd]

I know nothing about the development tools for the Aquarius or the signals available on the cart connector but how about a purely software solution? You'd have a boot ROM that copied itself to RAM for execution. It would then present a menu and then you could select the ROM to bank in and execute it. You'd just need a latch and obviously you'd also lose a "slot" in the cart for the boot code.

It's possible. I'm sure the cartridge slot has the signals for it, since it can accept both RAM and program cartridges. I've collected some freeware Z80 development tools that should be compatible with the Aquarius, so I should probably investigate this option further. After all, if I'm to change the design from hardware-based to software-based, now would be the time to do it.

 

In the meantime, hopefully my "other" Aquarius project will be enough to keep Aquarius owners busy ...

[GroovyBee]

I'm sure the cartridge slot has the signals for it, since it can accept both RAM and program cartridges.

 

I meant the RAM on the motherboard. No need to add extra RAM when it isn't needed.

 

I've collected some freeware Z80 development tools that should be compatible with the Aquarius, so I should probably investigate this option further. After all, if I'm to change the design from hardware-based to software-based, now would be the time to do it.

 

I'm sure if you get stuck you can ask for help in the Coleco programmers forum.

[jaybird3rd]

I'm sure if you get stuck you can ask for help in the Coleco programmers forum.

Thanks. I had thought of using cartridge-based RAM only because the Aquarius only has 4KB of onboard RAM, which might not be enough.

[GroovyBee]

Thanks. I had thought of using cartridge-based RAM only because the Aquarius only has 4KB of onboard RAM, which might not be enough.

If you keep to a short text description of what is in the other slots when you display the menu I would have thought that it should be more than enough. What hardware does the Aquarius BIOS initialise before it gets to the entry point in the cart? Does in init the screen, play a sound, etc?

[jaybird3rd]

If you keep to a short text description of what is in the other slots when you display the menu I would have thought that it should be more than enough. What hardware does the Aquarius BIOS initialise before it gets to the entry point in the cart? Does in init the screen, play a sound, etc?

I actually haven't learned much about the Aquarius initialization process as yet; detailed technical information for that system seems difficult to come by. I do know that, of the 4K of built-in RAM, only 1.7K is available to programs: 2K is used for screen data (1K for characters, 1K for colors), and another 256 bytes for other purposes. But, as you say, for a simple list it might be enough.

 

I should really look more closely into a software-based solution, now that I've thought about what you've said. Your idea is simpler than the way I thought it would have had to be done, and I'd like to avoid using switches if at all possible.

[coyo5050]

If you keep to a short text description of what is in the other slots when you display the menu I would have thought that it should be more than enough. What hardware does the Aquarius BIOS initialise before it gets to the entry point in the cart? Does in init the screen, play a sound, etc?

I actually haven't learned much about the Aquarius initialization process as yet; detailed technical information for that system seems difficult to come by. I do know that, of the 4K of built-in RAM, only 1.7K is available to programs: 2K is used for screen data (1K for characters, 1K for colors), and another 256 bytes for other purposes. But, as you say, for a simple list it might be enough.

 

I should really look more closely into a software-based solution, now that I've thought about what you've said. Your idea is simpler than the way I thought it would have had to be done, and I'd like to avoid using switches if at all possible.

 

If this is workable this would be the best solution of all! Software menus are hot, lol