Supercart I Modification / Daughter Board Question

[jaybird3rd]

If the mini expander is bidirectional then with suitable voltage conversion you could bit-bash an SPI interface to an SD card. The speed wouldn't be brilliant but you could get it down to a relatively low cost design.

Yes. Or even an FTDI bridge chip like the FT245R for a USB interface to a PC. That would be especially useful for development, since it would make it easy to download code to a real Aquarius for testing. Much more convenient than burning EPROMs.

[chjmartin2]

Why oh why did I pick THIS computer to work on. We don't have any tools.

[jaybird3rd]

Why oh why did I pick THIS computer to work on. We don't have any tools.

But we get to make those tools, better and cheaper ones than could have been made in the past, and there's fun in that also.

 

As far as new peripherals and hardware upgrades are concerned, I'm excited by all that can be done with the inexpensive technologies at our disposal today. Unlike other classic systems, for which new modifications and upgrades have to maintain backward compatibility with wide varieties of old hardware and software, the Aquarius is a nice, simple, open-ended system on which we can start almost completely from scratch. The real challenge will be to create well-engineered solutions which will fit into the Aquarius architecture in a natural way, without trying to change the Aquarius into something else.

 

Besides, I wouldn't exactly say that there are no tools: there are plenty of Z80 assemblers and C compilers out there for multiple platforms, there are tools and documentation for the 8910 PSG, there are the various converters you've been working on (along with the screen editor that I need to dust off and finish), and I'd like to think that the SuperCart filled an important void, too.

 

Personally, I'm delighted that somebody else has chosen an off-the-wall system like the Aquarius to tinker with. I don't want to disparage anyone else's efforts, but I sometimes get tired of seeing the same old arcade ports being done and re-done again and again on the same old platforms. I got involved with the Aquarius because I wanted to do something different, and I think it lends itself nicely to hobbyists like me precisely because so many of the design problems that have been solved on other retro platforms have not yet been solved on the Aquarius.

 

Perhaps you simply need to find a project idea that is more interesting or more challenging than what you've done before. I would suggest that you consider doing a game: experimenting with audio and video as a standalone project is one thing, but doing it as part of a larger project might be more rewarding, because you get to see your work put to use in a real "product" right away. I know it would have been more difficult for me to see the SuperCart design through to the end if I didn't already have the Aquaricart in mind, for example.

[chjmartin2]

I shouldn't have said we have no tools. You're right - without the Supercart - I'd have nothing to work with.

 

For me, I like to pull out an old console or computer and see what cool, tricked out stuff people have done with it, but on the real harware. For the Aquarius, I bought it and then found out there wasn't much tricked out stuff to choose from and so working on that was very rewarding on its own. I'm not unhappy about that at all! I still have some goals, I like the demo work. I've been thinking about a game or a port or something, just not sure where to go. How many homebrew carts would sell anyway? I show my family stuff and they roll their eyes and then they ask me, "Are there really people who look at this stuff?" I always find myself saying, "well yeah... like 5."

[intvnut]

Why oh why did I pick THIS computer to work on. We don't have any tools.

But we get to make those tools, better and cheaper ones than could have been made in the past, and there's fun in that also.

That's why I got into Intellivision. At the time I got in, there was only Carl's emulator, assembler and documentation, and it was all DOS-only, and parts of the assembler were buggy at the time. (I did make bug reports, though.)

 

Compared to the Z80-based Aquarius, the Intellivision had and still has far fewer tools available. At least the Aquarius benefits from the ubiquitous Z80 work out there. Heck... I wouldn't be surprised if you could take an F18A (the FPGA replacement for the TMS9918A VDP), wire it up to the Aquarius and run Colecovision or MSX games with only a little bit of patching.

 

As far as new peripherals and hardware upgrades are concerned, I'm excited by all that can be done with the inexpensive technologies at our disposal today. Unlike other classic systems, for which new modifications and upgrades have to maintain backward compatibility with wide varieties of old hardware and software, the Aquarius is a nice, simple, open-ended system on which we can start almost completely from scratch.

 

Indeed, it is something of a blank slate. It does have some architectural limitations that are harder to get around than others, such as the CG ROM.

 

The real challenge will be to create well-engineered solutions which will fit into the Aquarius architecture in a natural way, without trying to change the Aquarius into something else.

 

Nix my F18A idea then.

 

I don't want to disparage anyone else's efforts, but I sometimes get tired of seeing the same old arcade ports being done and re-done again and again on the same old platforms.

 

Guilty as charged... though I'd like to think I added at least something new to Space Patrol.

 

I got involved with the Aquarius because I wanted to do something different, and I think it lends itself nicely to hobbyists like me precisely because so many of the design problems that have been solved on other retro platforms have not yet been solved on the Aquarius.

 

That's why I started jzIntv and SDK-1600 way back in the late 90s, and helped Chad work out the quirks of the Intellivision bus when he designed the Intellicart. I stood on the shoulders of Carl's immensively helpful reverse engineering work and Willy's documentation to do my own. Point is, a lot of the fun has been the collaboration building the community and filling in these gaps. Carl's work was a great starting point, but as we've seen, the Intellivision home brew scene was only just beginning all those years ago, and there's still more to come. :-)

 

It looks like with the Aquaricart, things are starting to heat up over here, too. :-)

Edited March 15, 2012 by intvnut

[jaybird3rd]

Compared to the Z80-based Aquarius, the Intellivision had and still has far fewer tools available. At least the Aquarius benefits from the ubiquitous Z80 work out there.

Indeed. One reason I picked the Aquarius was that it gave me the chance to learn Z80 assembly (I already had some 6502 experience). But beyond that, I've always wanted to try my hand at using Knuth's "literate programming" approach on a real project, and I'd also like to have the option of porting whatever I create for the Aquarius to other more "mainstream" platforms. Using C seems like a good way of achieving both goals, and fortunately, there are lots of C compilers for the Z80 as well.

 

But I must say that I'm very impressed with the sdk1600 tools and sample code. I've only tinkered with them so far, but the Intellivision is definitely a system I intend to write for someday ... if I can ever find enough free time.

 

Guilty as charged... though I'd like to think I added at least something new to Space Patrol.

Believe me, I didn't intend to pick on Space Patrol at all! I was thinking more of the recent homebrew activity on the Atari 2600 and (especially) ColecoVision systems, which seems preoccupied with two questions in the selection of new projects: "Does this resemble an old game that I already know?", and "Will this sell lots of copies to collectors?". Usually, the only games that get made are the ones that can satisfy both of those questions, which has left homebrew on those systems stuck in a rut. It's an old complaint of mine.

 

I can certainly understand working within familiar game forms when one is first learning a system, or developing a set of tools for it, since it frees the programmer from having to figure out new game designs on top of everything else. My first two Aquarius games will be (non-trademark infringing) takes on popular titles for that reason. But once I've earned my sea legs with the hardware and tools, I intend to shift my focus to game design, which I consider to be a distinct activity from game programming.

 

Indeed, it is something of a blank slate. It does have some architectural limitations that are harder to get around than others, such as the CG ROM.

Nix my F18A idea then.

Heh ... it might be easier to just drop in an F18A than it would be to get around that stupid character generator ROM! Some of your suggestions have been helpful toward solving that problem, though.

 

I stood on the shoulders of Carl's immensively helpful reverse engineering work and Willy's documentation to do my own. Point is, a lot of the fun has been the collaboration building the community and filling in these gaps. Carl's work was a great starting point, but as we've seen, the Intellivision home brew scene was only just beginning all those years ago, and there's still more to come. :-) It looks like with the Aquaricart, things are starting to heat up over here, too. :-)

I'm delighted that the Aquaricart project turned out so well (except that it took a lot longer to finish it than I wanted). I drew a lot of inspiration from Chad's work on the Cuttle Cart 3 in the design of the Aquaricart software, as anyone who's used both cartridges can probably tell, so there's still a lot of "cross-pollination" going on between the Intellivision and Aquarius. Here's hoping that it continues as both systems attract more homebrew support!

[jaybird3rd]

I shouldn't have said we have no tools. You're right - without the Supercart - I'd have nothing to work with.

 

For me, I like to pull out an old console or computer and see what cool, tricked out stuff people have done with it, but on the real harware. For the Aquarius, I bought it and then found out there wasn't much tricked out stuff to choose from and so working on that was very rewarding on its own. I'm not unhappy about that at all! I still have some goals, I like the demo work. I've been thinking about a game or a port or something, just not sure where to go. How many homebrew carts would sell anyway? I show my family stuff and they roll their eyes and then they ask me, "Are there really people who look at this stuff?" I always find myself saying, "well yeah... like 5."

I'm relieved to hear you're still having fun. I was concerned that you'd get frustrated and quit the Aquarius!

 

It's still difficult to say how many copies of an Aquarius homebrew one can reasonably expect to sell. My experience with the Aquaricart is only informative to a certain extent, because in that case, it was a compilation of original Aquarius software that was interesting to collectors in a way that new releases might not be (although I think it's likely that Aquarius collectors would want homebrew, too). If I had to put a number on it, I'd say that about forty to fifty copies would be a good estimate, depending on the game and the price.

 

There is also the problem of producing assembled cartridges with shells and boxes ... although there just might be a solution in the works for the cartridge shell problem, and as a consequence, the box problem as well!

[chjmartin2]

I can make copies of the cart shells. I make copies of plastic stuff all of the time using silicone molding gel and epoxy for the parts!