Cheap cartridges for developers and gamers

[nathanallan]

Okay, but hey, I had to ask

[+batari]

Initially we wanted it to include 8 megabytes of memory, but the cost was significantly higher, so we settled on 4 megabytes.

Couldn't you have added footprints for extra flash chips (at least to 6MB) to the board and leave them normally unpopulated? Or, allow for larger flash chips with same footprint? I realize there may be some extra decode logic, but maybe that could be normally unpopulated as well.

[Zerosquare]

Adding a footprint for a second flash chip would have complicated the routing noticeably.

 

Initially we wanted to include support for larger flash chips with the same pinout, but it required an extra voltage translation chip (the flash memories are 3.3 V, while the Jaguar I/Os are 5 V) : by sheer coincidence, all available buffers in the chips are actually used.

 

In addition to this, the board uses SMD parts exclusively, and the flash memory chip leads are only 0.5 mm (0.02 inches) apart from each other, which makes soldering beyond the ability of the average hardware tinkerer.

 

In light of this, we decided that the 8 MB model wasn't worth the trouble ; and now that the prototypes have been shown to work, wed'd prefer not to alter the PCB artwork if we can avoid it.

Edited September 23, 2010 by Zerosquare

[nathanallan]

Thinking of the ram upgrading trick of piggybacking a chip on a chip, could that be possible?

 

Not sure of the design of this type of ram, but there was a trick you could use on a C64 iirc where you jumpered one wire and were able to have more ram that way. I know the architecture is different but would something like that be possible?

 

Brainstorming again, and just had to ask it.

[+CyranoJ]

Well, to be fair, the largest homebrew released to date is Superfly and these carts are more than 2x bigger than what that uses - and also remember that we have to load the data into RAM for Superfly, whereas in a cart it could be left in ROM space, so really its 3 to 3.5x more storage in "real world" terms.

 

For the immediate future, 4mb is plenty.

[Zerosquare]

Not sure of the design of this type of ram, but there was a trick you could use on a C64 iirc where you jumpered one wire and were able to have more ram that way. I know the architecture is different but would something like that be possible?

In theory, yes.

 

In practice... as I said above, the Flash memory pins are only 0.5 mm (0.02 inches) apart. That's more than five times smaller than on a C64's chip !

 

Piggybacking would be almost impossible.

Edited September 23, 2010 by Zerosquare

[Atari_Owl]

Well, to be fair, the largest homebrew released to date is Superfly and these carts are more than 2x bigger than what that uses - and also remember that we have to load the data into RAM for Superfly, whereas in a cart it could be left in ROM space, so really its 3 to 3.5x more storage in "real world" terms.

 

For the immediate future, 4mb is plenty.

 

I wouldn't object to more though - if possible... later on.

[nathanallan]

Piggybacking would be almost impossible.

"Almost" is not "utterly" so there is some wiggle room there. Humanly difficult, but what if a machine were to do it? The chips get there somehow, so might be a possibility.

 

Has anyone ever had these things piggybacked? I'm sure I have ran across some really weird RAM modules for computers, stacks of chips, but again, they were larger "legs" attaching them.

 

I bet a machine could do it near perfect.

 

Sorry, not to be pestering but I have been thinking outside several boxes today, necessity breeds invention.

 

Nathan

[JagChris]

Piggybacking would be almost impossible.

"Almost" is not "utterly" so there is some wiggle room there. Humanly difficult, but what if a machine were to do it? The chips get there somehow, so might be a possibility.

 

Has anyone ever had these things piggybacked? I'm sure I have ran across some really weird RAM modules for computers, stacks of chips, but again, they were larger "legs" attaching them.

 

I bet a machine could do it near perfect.

 

Sorry, not to be pestering but I have been thinking outside several boxes today, necessity breeds invention.

 

Nathan

 

What necessity? lets cross that bridge if we ever get to it. When someone is producting stuff that pushes the 4mb limit on these carts then we should worry about going further.

[Zerosquare]

"Almost" is not "utterly" so there is some wiggle room there. Humanly difficult, but what if a machine were to do it? The chips get there somehow, so might be a possibility.

Unlike older components, chips that small are not soldered pin by pin. Soldering paste is applied, and the whole board is "baked" in a special temperature-controlled oven. Trying to piggyback something that way would only cause a big mess, the process is definetely not designed for that kind of thing.

 

Even if you managed somehow to piggyback an additional chip, it would be very fragile and unreliable. The solder joints of the upper chip would be tiny and wouldn't have enough mechanical resistance.

 

You can't tinker with modern hardware like you could in the past

[Starcat]

For the immediate future, 4mb is plenty.

I wouldn't object to more though - if possible... later on.

 

Same here. It may not be necessary for most Jag releases, but it would be cool to have an option in the future to allow bigger releases if it's needed.

[+batari]

Adding a footprint for a second flash chip would have complicated the routing noticeably.

The routing of the board does look nice, but I'd consider that a minor consideration if it could allow an extra chip. An extra chip should not require more outputs on the voltage converter as its chip enable could be driven through a single SOT-323 transistor and pullup resistor, that could be unpopulated if the extra chip wasn't there.

Initially we wanted to include support for larger flash chips with the same pinout, but it required an extra voltage translation chip (the flash memories are 3.3 V, while the Jaguar I/Os are 5 V) : by sheer coincidence, all available buffers in the chips are actually used.

A single three cent transistor and pullup resistor could be added to the board to handle the one extra address line needed and could be left unpopulated for the smaller chip.

In addition to this, the board uses SMD parts exclusively, and the flash memory chip leads are only 0.5 mm (0.02 inches) apart from each other, which makes soldering beyond the ability of the average hardware tinkerer.

I wasn't suggesting that average tinkerers do it, but that you do. Also, there are several members here who can solder chips like that (myself included - I solder 0.5mm LQFP chips for Harmony carts and those are much harder than the chips on this board with just two rows of pins.)

In light of this, we decided that the 8 MB model wasn't worth the trouble ; and now that the prototypes have been shown to work, wed'd prefer not to alter the PCB artwork if we can avoid it.

All I'm saying is future-proofing the board may be something to consider, even if it means going back to the drawing board for one more proto run.

[+Sauron]

All I'm saying is future-proofing the board may be something to consider, even if it means going back to the drawing board for one more proto run.

 

These carts are meant as an inexpensive option for developers to publish games on cart, with the key word here being inexpensive. As someone else said before, we can cross the "large capacity" bridge when we get there, but for right now, there's little need to as most homebrew games don't even hit a full 2MB., let alone 4. Going back and doing another proto run just to get a larger cart size is going to add more time and expense for them, and I know that several devs are quite anxious for these carts to become available ASAP. If homebrew developers start pushing the limits of that storage capacity, by that time they'll be in a better position to look into creating a larger cart size. For now, though, this is giving the community a much better option than it's had before.

[busterm]

All I'm saying is future-proofing the board may be something to consider, even if it means going back to the drawing board for one more proto run.

 

These carts are meant as an inexpensive option for developers to publish games on cart, with the key word here being inexpensive. As someone else said before, we can cross the "large capacity" bridge when we get there, but for right now, there's little need to as most homebrew games don't even hit a full 2MB., let alone 4. Going back and doing another proto run just to get a larger cart size is going to add more time and expense for them, and I know that several devs are quite anxious for these carts to become available ASAP. If homebrew developers start pushing the limits of that storage capacity, by that time they'll be in a better position to look into creating a larger cart size. For now, though, this is giving the community a much better option than it's had before.

 

I 100% agree with this. Lets get it out ASAP for all to enjoy. Larger is something that can definitely be handled later when there is actually a game to take advantage of it.

[+batari]

All I'm saying is future-proofing the board may be something to consider, even if it means going back to the drawing board for one more proto run.

 

These carts are meant as an inexpensive option for developers to publish games on cart, with the key word here being inexpensive. As someone else said before, we can cross the "large capacity" bridge when we get there, but for right now, there's little need to as most homebrew games don't even hit a full 2MB., let alone 4. Going back and doing another proto run just to get a larger cart size is going to add more time and expense for them, and I know that several devs are quite anxious for these carts to become available ASAP. If homebrew developers start pushing the limits of that storage capacity, by that time they'll be in a better position to look into creating a larger cart size. For now, though, this is giving the community a much better option than it's had before.

The boards would not cost any more to produce with the suggestions I noted, and proto runs these days can be done dirt cheap and don't take too long. A single transistor, single resistor and a few extra traces are pretty minimal. I'd even donate a thousand transistors to the project if that would help (though these are really not expensive - as stated I paid three cents each for them.)

[+Sauron]

The boards would not cost any more to produce with the suggestions I noted, and proto runs these days can be done dirt cheap and don't take too long. A single transistor, single resistor and a few extra traces are pretty minimal. I'd even donate a thousand transistors to the project if that would help (though these are really not expensive - as stated I paid three cents each for them.)

 

Those are all good points, but I think it would be better to wait for a future run for that kind of modification. I and many others are more anxious to see the current design get into people's hands ASAP. Just my opinion though.

[carmel_andrews]

Zero Square/Batari....Would I be right in saying then that having socketed chips on motherboards are more expensive to make (per unit) then Surface mounted chips on motherboard (re: your flashcart device)

 

I only mention this because, you could offer people the option of upgrading the flashcart to adding more memory (like 8 meg, as someone mentioned), which would be somewhat easier with socket chipped motherboards i would guess

[GroovyBee]

The sockets required for the surface mount devices would be too expensive to make it a viable solution. As others have said I say ship with 4M and then look at larger carts later.

[+batari]

The boards would not cost any more to produce with the suggestions I noted, and proto runs these days can be done dirt cheap and don't take too long. A single transistor, single resistor and a few extra traces are pretty minimal. I'd even donate a thousand transistors to the project if that would help (though these are really not expensive - as stated I paid three cents each for them.)

 

Those are all good points, but I think it would be better to wait for a future run for that kind of modification. I and many others are more anxious to see the current design get into people's hands ASAP. Just my opinion though.

It's up to the developers of course, but the modifications are minimal in my opinion, assuming the 8MB chip can use the same footprint and just needs one extra address line (which is likely.)

 

Also, I just realized that an address line is output only so a transistor wouldn't even be required for 5v-3.3v conversion - two resistors in a voltage divider setup is all that would be needed, and in quantity, these resistors less than a penny each. Also, if 2.5v is a valid logic level (it probably is) then the same resistor value could be used for both resistors.

[matmook]

4MB is far enough to fill with packed data... (Rayman is a 4MB game !!!!!).

[nathanallan]

Right, I agree with the inexpensive part of it, I was thinking of taking an inexpensive cart and upgrading it later. That's all.

 

I still would love to get one if I could swing it.

[carmel_andrews]

Nice looking carts/device....But before we all get excited, We need some games from jaguar developers/publishers to put on these devices....So lets have the games.....please

 

And not just 'some' games, LOTS OF GAMES

Edited September 25, 2010 by carmel_andrews

[mellis]

Nice looking carts/device....But before we all get excited, We need some games from jaguar developers/publishers to put on these devices....So lets have the games.....please

 

And not just 'some' games, LOTS OF GAMES

 

Sounds good. I suggest you get busy writing some code, Carmel.

[carmel_andrews]

Nice looking carts/device....But before we all get excited, We need some games from jaguar developers/publishers to put on these devices....So lets have the games.....please

 

And not just 'some' games, LOTS OF GAMES

 

Sounds good. I suggest you get busy writing some code, Carmel.

 

 

 

 

 

give me or let me at your coding/programming brain then....so i can suck it dry

[+CyranoJ]

give me or let me at your coding/programming brain then....so i can suck it dry

 

Instead of you going around decapitating people and sucking them dry, might I suggest you start with The Spectrum Book of Games by Mike James, S.M. Gee and Kay Ewbank.

 

I'm sure there will be plenty in there for you to learn from