Chimera Hybrid Game System

[+selgus]

Yes, the microcontroller is doing a lot of work in between cycles. It took me a long time to get it working, but it does work. However, the 6507 is fairly forgiving and flexible about timing. The microcontroller runs at 70 Mhz, so you have about 58 cycles of microcontroller code per 2600 cycle. This of course means that you must write 100% assembly code for the microcontroller and write it efficiently.

Which microcontroller are you using on the boards?

--Selgus

[+batari]

Yes, the microcontroller is doing a lot of work in between cycles. It took me a long time to get it working, but it does work. However, the 6507 is fairly forgiving and flexible about timing. The microcontroller runs at 70 Mhz, so you have about 58 cycles of microcontroller code per 2600 cycle. This of course means that you must write 100% assembly code for the microcontroller and write it efficiently.

Which microcontroller are you using on the boards?

--Selgus

It's an ARM, with 32k flash and 8k SRAM, with its GPIO bus connected directly to the 2600's bus. The design of the board itself is fairly simple, and getting it functional is almost entirely a programming exercise. In some sense it's a lot like programming the 2600 itself, in that the hardware is simple but powerful with good programming, and to make it sing and dance, you have to write a kernel of tight asm code.

[Sdw]

Nice project batari! Good to hear that there might be an alternative to the Chimera. I need something so I can test my homebrew, at the moment I use EPROMs, but I have no UV-eraser, so I have to be VERY selective on when it is time to test something!

 

Do you have any idea on which price-point it might end up at? Are we talking like $50 or so, which means that even a casual developer like me would be interested in picking one up, or is it more of $200 premium item for the hardcore crowd?

[mos6507]

Even the fullblown chimera wasn't going to sell for more than $50. So I would hope Harmony would be significantly less, considering that it is intended to house homebrews for the AA store.

[+selgus]

Even the fullblown chimera wasn't going to sell for more than $50. So I would hope Harmony would be significantly less, considering that it is intended to house homebrews for the AA store.

As batari has said, the hardware is actually very simple, so that wouldn't be driving the cost of the unit. It is going to be the effort involved with writing the firmware and getting all the timings correct. I like the idea of getting a board up and running, getting a subset of the software working and doing an iterative approach. This is the expectation I put on the guys whom work for me, and has proven in my experience, to get products to market faster and of higher quaility.

 

These 2600 homebrew hardware projects seem to start off strong, and then sizzle out. Lets hope this is the exception.

 

--Selgus

[+batari]

Even the fullblown chimera wasn't going to sell for more than $50. So I would hope Harmony would be significantly less, considering that it is intended to house homebrews for the AA store.

Keep in mind there are two versions. One is a standalone version with minimal parts, intended for single homebrew games. Of course this version will be "significantly less" than $50 - if things go as planned, it will house future homebrews and also present homebrews that currently sell for $25-ish.

 

The other is a developer's version, which requires several additional parts (ribbon cable, daughterboard, USB chip, USB connector, serial EEPROM, SD card slot, software CD) and additional assembly labor. Also, the components on the daughterboard will be purchased in smaller quantities, which tends to drive up costs a bit.

 

Really, the main goal of Harmony was a low-cost, solderless solution for homebrew releases, and I believe that goal will be met. So far it has exceeded expectations, in that RAM bankswitching methods work, and even Pitfall II is running on a Harmony cart, which no other board can do.

 

The developer's version was kind of an afterthought - it occurred to me that it would be possible to fill a currently empty niche in the market as CC/CC2/Kroko carts aren't available anymore, and as a stopgap until Chimera is finished. It was not intended to compete with Chimera, and it's not really a scaled-down Chimera either, although they have a few similarities.

 

Also, the Chimera board was going to be hand-assembled by you for free. The Harmony board and the daughterboard for the developer's version will be machine-assembled, and that won't be free. The Chimera was to be sold without profit, while I'd expect there to be a small profit with Harmony developer's boards if it will help support this site.

 

So while the standalone Harmony will be significantly less than Chimera, but I really can't promise that the Harmony developer's board will be. I don't think it will be more, though.

[+selgus]

So while the standalone Harmony will be significantly less than Chimera, but I really can't promise that the Harmony developer's board will be. I don't think it will be more, though.

I think as long as these boards come out, many people aren't so worried about the price. Look how much people are willing to pay for old used dev 2600 carts?

--Selgus

[nonner242]

Cant wait for this!

[Foster]

I'm anxious to see the Harmony project come to fruition too. Any idea how it's progressing?

[mos6507]

Cant wait for this!

 

Looks like you're going to have to You and me both.

[+batari]

I'm anxious to see the Harmony project come to fruition too. Any idea how it's progressing?

I finished the new layout earlier this week and just ordered some boards. I'm using batchpcb so it will probably be about a month before I get the boards, but batchpcb's prices can't be beat. So it is progressing, slowly but surely.

[MausGames]

The Harmony cart also has a SD-card interface. It's not clear if we'll be able to make it work acceptably well, however, as so don't get your hopes up.

 

I really hope this feature works out, I think it would be extremely useful. Do you mean standard SD cards, or mini/microSD?

[+batari]

The Harmony cart also has a SD-card interface. It's not clear if we'll be able to make it work acceptably well, however, as so don't get your hopes up.

 

I really hope this feature works out, I think it would be extremely useful. Do you mean standard SD cards, or mini/microSD?

Standard, but mini and micro could be used with an adapter.

[accousticguitar]

I finished the new layout earlier this week and just ordered some boards. I'm using batchpcb so it will probably be about a month before I get the boards, but batchpcb's prices can't be beat. So it is progressing, slowly but surely.

So that would be a small batch of boards to test the new layout?

[+batari]

I finished the new layout earlier this week and just ordered some boards. I'm using batchpcb so it will probably be about a month before I get the boards, but batchpcb's prices can't be beat. So it is progressing, slowly but surely.

So that would be a small batch of boards to test the new layout?

Just a few boards right now. The last two prototypes had mistakes that needed to be corrected with hacked on resistors, and I'm hoping this one doesn't, but I didn't order too many in case it does. If it works as is, then I'll order more and do a small batch for more extensive beta testing.

[accousticguitar]

Sounds good. Here's to hoping this one works perfectly.

[+selgus]

I finished the new layout earlier this week and just ordered some boards. I'm using batchpcb so it will probably be about a month before I get the boards, but batchpcb's prices can't be beat. So it is progressing, slowly but surely.

BatchPCB does have some nice prices. I will keep them in mind for my next project.

--Selgus

[MausGames]

The Harmony cart also has a SD-card interface. It's not clear if we'll be able to make it work acceptably well, however, as so don't get your hopes up.

 

I really hope this feature works out, I think it would be extremely useful. Do you mean standard SD cards, or mini/microSD?

Standard, but mini and micro could be used with an adapter.

 

Standard SD is best. Would it be possible for bB games to access the SD card? Will it have an auto-load feature if there is only one bin on the card?

[+selgus]

Standard SD is best. Would it be possible for bB games to access the SD card? Will it have an auto-load feature if there is only one bin on the card?

Personally I just like having flash, and a means to update it from a USB port. Do you really need to swap in and out different SD cards? Are you asking for just more space to store ROMs? You can always just have a higher density flash chip.

--Selgus

[+batari]

Standard SD is best. Would it be possible for bB games to access the SD card? Will it have an auto-load feature if there is only one bin on the card?

Personally I just like having flash, and a means to update it from a USB port. Do you really need to swap in and out different SD cards? Are you asking for just more space to store ROMs? You can always just have a higher density flash chip.

--Selgus

The microcontroller has a flash size of 32k so it could accommodate most games without any additional flash. While it can read MMC/SD cards, it also has a footprint on the board for an external flash chip, and I've found them up to 4 MB. If these chips are still inexpensive when the Harmony dev board is ready, I can include them. These chips cannot easily be socketed, however, as they are SOIC. The board also has a DIP socket but the available sizes are much smaller than 4 MB (that I've found, anyway.)

 

If someone wants more than 4MB or wishes to read/write games with a card reader on their PC instead of through USB (which is a tad slow) then the MMC/SD should be able to be used instead of the onboard flash.

 

I will get the board going with the onboard flash first and MMC/SD support will come later. It should be much easier to support the onboard flash.

 

I don't know how useful it would be for bB games to access the SD card, as it's not RAM, so it takes a relatively long time to read and write, and you can only access chunks at a time (can't recall the size of the chunks but it's probably something like 512 bytes at a time.)

[MausGames]

Personally I just like having flash, and a means to update it from a USB port. Do you really need to swap in and out different SD cards? Are you asking for just more space to store ROMs? You can always just have a higher density flash chip.

--Selgus

 

No, I'm asking for the ability to release Atari 2600 games on $5 SD cards, complete with tiny printed label. I don't know why (besides cost-effectiveness), but this really appeals to me. That's also why a built in auto-start for carts/cards with only rom is important to me.

 

http://www.hitechvendors.com/p-4702-64mb-s...nomic-card.aspx - It's cute, it's cheap, it's begging to be the latest distribution method for enhanced 2600 games. Those are $2.75, and there are decent USB sd readers available for about $2; that means for $4.75 I could produce a tiny 2600 cart with reader for loading on additional levels, updated bins, etc (why I asked about bB compatibility).

Edited February 18, 2009 by MausGames

[+selgus]

No, I'm asking for the ability to release Atari 2600 games on $5 SD cards, complete with tiny printed label. I don't know why (besides cost-effectiveness), but this really appeals to me. That's also why a built in auto-start for carts/cards with only rom is important to me.

Ahh, okay, I didn't even think about using it for the distribution model of game being sold for the 2600. You would need to have one of these boards though, not sure how practical that would be.

The last batch of EPROMs I bought were only a few dollars each, though they are only 32K.

--Selgus

[MausGames]

True, which is why I was really hoping that the SD slot would be a standard feature, and not end up as an added developer feature, but either way if it's there I could take advantage. If there are two version of Harmony- a multicart-usb version, and the developer multicart-usb-sd version, that could pose a problem.

[+batari]

In case it's not clear, I'd imagine that many users of a Harmony developer's cart would not use it to develop, but instead to play games.

 

If the SD interface will work, then yes, one could release games that way. It may not be practical unless the Harmony developer's cart becomes ubiquitous. We've also talked about a "mini-cart" which would be a serial EEPROM on a tiny board, roughly the same size as an SD card. A blank mini-cart would probably cost less than an SD card, and the mini-carts could also be programmed with a Harmony developer's cart.

 

It's not clear if either would appeal to game buyers - my impression is that they would prefer a standalone cart than a tiny "cart" that only works with a Harmony developer's cart.

[+selgus]

It's not clear if either would appeal to game buyers - my impression is that they would prefer a standalone cart than a tiny "cart" that only works with a Harmony developer's cart.

That's my gut feeling too, but you never know. I thinking having Harmony out there will open up that opportunity, though keeping the costs down will allow even more user to purchase said cartridge.

--Selgus