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Homebrewed Games - Custom Cart PCB's


Junie

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I've never been able to find PROMs. I can only find EPROMs. I might use them if they were cheaper, but I only pay $2 for 2532s.

 

Yeah, a multicart board has to be twice as big because you have to put a big EPROM in the empty space in the top. They won't fit where the Atari PROM goes without modifying the case.

 

-Paul

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Junie,

 

On the picture all connections are on the side of the board shown. (Back of board) The colors don't mean anything. The 74LS04 has 6 logic inverter gates on it, the cart only needs one of them. That's why only 4 wires are used. Atari chose to invert the chip select line on their cart design, you need to invert it through the 7404 to make it compatible with an eprom or a standard prom. If you want to see the spec sheet for a 74LS04 it's at http://www.fairchildsemi.com/ds/DM/DM74LS04.pdf

 

BTW Ubersaurus, I have lots of eeproms that are over 20 years old, I've never had one lose it's contents yet. Quite a few games from smaller companies came on eproms. You probably have some in your collection.

 

-Chuck

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quote:

Originally posted by C. Schell:

Oh, and as long as I'm posting on this thread. If you're going to make yet another PCB for doing homebrews, please ground the unused inputs on the 7404. It's such bad practice to just leave them floating.

 

Thanks for the tip. Do you have any other suggestions?

 

quote:

Originally posted by ubersaurus:

Good point, we may end up just going supercharger style after all. Problem is that there aren't that many superchargers, so we'd probably end up having to make new ones, renamed and all that, to sell with our games. Though certainly this will make programming a bit easier.

 

I personally don't like the SuperCharger style. No it isn't because I am in the process of creating PCB's, it is simply because they are nothing more than cassettes.

 

At some point or another it seems all of my music cassettes have been "ate" by the player, which of course causes stress on the tape itself and of course the constant breaking.

 

That doesn't seem any better than Eproms, instead it sounds a lot worse.

 

Anyway...

 

I have started to design the PCB for the 2732 and the LS7404 chips. Everything has been measured and made to actual size.

 

I have printed out the PCB and compared it to the original PCB and everything is fine.

 

I'll have the PCB layout done soon and post the images (both sides) for anyone's ideas, suggestions, or problems found.

 

I hope to start creating the actual PCB's in the next week or two. Once the PCB has been actually tested I will start work on various other PCB's. For example the Multi-Cart design and any other PCB ideas or different chips needed that have been posted in this thread.

 

If you have a PCB that hasn't been listed or what not, simply make a post and I'll add it to my list.

 

Junie

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quote:

Originally posted by khryssun:

Just wondering...

do you think it will work to replace a 2764 Eprom with a 2864 EEPROM ?

 

 

BTW do you know if there's a good ressource on the web which explain how to build PCBs ?

 

As far as the Eprom hopefully someone else can anwser that, I don't program games so I am not very knowledgeable about that. I am learning though

 

For websites explaining how to create PCB's just do a search on a search engine. You should find sites that explain how to create basic PCB's quite easily.

 

If you are looking for advanced topics like cutting PCB's, good luck. The only things I have ever found are catalogs with tools starting out at $500 or more.

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quote:

Originally posted by Junie:

I personally don't like the SuperCharger style. No it isn't because I am in the process of creating PCB's, it is simply because they are nothing more than cassettes.

 

Although the original releases for Supercharger came on cassettes, the Supercharger isn't married to the audiocassette format; it just needs an audio signal. You could use a CD, a computer, an MP3 player, etc. to feed the audio signal to a Supercharger.

 

That said, actual cartridges are also nice.

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Actual carts are great, there's just something to be said with games that will last a considerable amount of time. With proper care, a cd will outlast an eprom. And with the prices of ROM chips and ROM Burners, it may just be cheaper to do this. I mean, yeah, we could go for EPROMS, but we don't want to make games that die after a decade or two.

Sides, this way we could do a special version for the cuttle cart, time permitting

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Just to spark some interest here is the current state of my PCB layout for the Eprom 2732 and the LS7404 hex inverter, the two chips are wired as explained by Chuck Gill . The image shows the front of both, a original Atari PCB and my PCB layout.

 

atari_pcb_layout.jpg

 

As suggested by C. Schell the unused inputs from the LS7404 chip are grounded.

 

The outline of the PCB is actually very slightly larger than the original PCB, this gives me a cut on the line effect.

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One quick, but vital correction for you. It looks like you've grounded ALL the unused pins. That's bad. You want to only ground the inputs, not the outputs. There are a total of 6 inputs and 6 outputs on the chip, plus a ground and a power pin. So a total of 6 pins (ground and 5 inputs) should be connected to ground. Look in the data sheet for which pins are inputs and which are outputs.

 

Chad

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The unused input pins are 3, 5, 9, 11, 13.

 

Pin 7 on the data sheet is Ground and pin 14 is the Power, but with the picture from Chuck for instructions Pin 7 is connected to the Eprom pin 24 and Pin 14 is grounded.

 

Does this sound right or am I just reading the picture wrong? I am reading the picture as the bottom right pin shown as Pin 1 (The chip is upside down)

 

Here is the picture

http://www.zutco.com/atari/Board.jpg

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I've got an update on using PROMs. I found out it is true that most modern EPROM burners do not support PROMs unless they are using EPROM technology. And even if I could find a burner that did support them, I can't find anybody who has the chips. The only other option is to have a chip-maker produce custom ROMs with the game data on them. I'll look into this, but I expect it will be too expensive. Looks like we may just have to buy new copies of homebrews and prototypes from Hozer in 20 years. ;c)

 

-Paul

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Looks like this message thread has fallen to the wayside.

 

Well after doing the math on such a endevor, it appears creating PCB's is not worth the time/effort.

 

As in my original post in this thread, the PCB would cost around $1.00 each. Well that would only be $0.15 profit for each PCB.

 

Lets say you did it really fast by hand, 5 minutes per PCB (In reality more like 10 minutes or more). And you wanted to make 150 PCB's, that would take about 12 1/2 Hours at 5 minutes for each PCB.

 

At $0.15 profit for each PCB, you would profit $22.50 from 150 PCB's.

 

Now if you figure out your profit per hour you are making $1.80 an hour. The minimum price an employer can pay a worker an hour is $5.25 according to the US Federal Government, so in other words if you flip a burger at McDonalds you would be a lot better off

 

Of course if you don't manage to even sell the PCB's created for $1.00, subtract that from the amount.

 

To say the least getting paid a $1.80 an hour isn't "cutting my bacon", I have lost all current interest in this idea.

 

People barked at the idea of $1.00 a PCB, for someone to actually make a decent profit the PCB's would have to be sold at $2.29 each. At $2.29 for each PCB the creator would make the $5.25 per hour rage.

 

Once again, the prices are if you can create the PCB in 5 minutes a PCB.

 

So it seems all Homebrewed gamers will have to destroy the original Atari carts. No matter how cheap you can make the PCB at cost, the price can't compare to the $0.50 for a original common Atari game.

 

The only way this idea might work is if you can create the PCB in a lot less time. For example if you have a machine automated PCB factory you might be able to pull this idea off successfully.

 

Well I myself, am putting this idea on the back burner. Perhaps one day Homebrewers or Hozer might be interested in purchasing the PCB's, but for right now the price would be $2.29 each, and I don't see that it is possiable.

 

Even if people are interested in the PCB's for $2.29 each this still doesn't solve the problem, saving all games from "re-use". Someone would have to create new cart cases, and people would have to buy and use them too, otherwise everyone will still have to destory the games to get the cases needed.

 

Seems like the idea of saving the original Atari games is impossiable. I myself will dread seeing games become higher on the rariety list simply because of Homebrewed games, but what can be done?

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  • 2 months later...

quote:

Originally posted by Junie:

As mentioned in a lost thread, some people are interested in creating custom/new PC board's and Cart cases.

 

I personally have looked into making a new PCB for the Homebrewed Gamers. I don't have any fancy PCB cutters or anything, but I have been exprimenting and basiclly created the Atari cart PCB with common tools I have.

 

The cheapest price I have found for the rough 2" x 2" double sided PCB would cost $0.48 and have found a way to etch the PCB for about $0.15

 

Throw in some solder (To connect the 2 sides at the points) and the material to cover the PCB and your looking around $0.85 a PCB.

 

Then add in a very small profit to cover the time involed and your around $1.00 a PCB.

 

The resulting PCB is professional grade PCB. The etched PCB is always acurate and high quality.

 

I am not sure if Randy at Hozer or any of the other Homebrewed gamers are willing to pay $1.00 for the PCB, when they can get games for $0.25 - $0.50 for both the game case and PCB.

 

I have gotten PCB software to customize the PCB so that the PCB is acutally customized for Homebrewed games. No more connecting pins together or wiring pins to other places, simply solder the Eprom in the PCB and your all ready to go.

 

If I can find a cheaper supplier of double sided copper clad PC board then perhaps the cost will be cheap enough for Homebrewed games to want the PCB's. Or perhaps they do now..

 

Of course you have to remember this is a brand new, freshly created customized, PCB-- So it will cost more.

 

If anyone knows where to buy a 2" x 2" double sided PCB for less than $0.48 please respond. The supplier I found sells the PCB in much larger boards. I simply calculated how many 2" x 2" squares would fit on the board and divied the cost of the PC board by the amount of squares.

 

Anyone have any thoughts on this or are working on creating custom/new Atari cart cases?

 

Junie

 

 

Hey Junie, I have a question about this. Do you think it would be possible for you to make the boards to fit an Activision cart instead of Atari? I always liked the Activision style carts and, if I ever make a game, would want it in one. Activision carts, IMO, just seemd to have more style

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Hmm. As much as I love the homebrew industry, this will always be the part I don't like; the seedy underside to the new classics, the genocide of old ones. However, at some point in the future, some entrepenuer may decide that there is a market for mass production of carts and stuff, and do so. However, the homebrew thing will have to get alot bigger for that to occur. But at this rate of expansion, it could very well end up

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quote:

Originally posted by MoonlightKnight:

Hey Junie, I have a question about this. Do you think it would be possible for you to make the boards to fit an Activision cart instead of Atari? I always liked the Activision style carts and, if I ever make a game, would want it in one. Activision carts, IMO, just seemd to have more style


 

Digging up old posts, eh?

 

I would agree, I originaly thought about making them to fit the Activision cases. I even took apart my very bad half missing labeled, Kaboom game to study the inside of the Activision case and PCB.

 

The answer is Yes. They could be made to fit into the Activision cases, but I don't have much interest in doing it.

 

Eveyone seems to like the Atari brand labels and everything better. Not to mention that some poor Activision games would have to be killed for their cases, so why not use the Atari brand game Combat?

 

I planned on making the PCB's by hand myself, and I don't want to get into doing that when Atari brand PCB's can be bought brand new commercially made for $1.00

 

I was also playing with the idea of Activision PCB's when I was trying to get brand new cases made, which I am still trying to do.

 

Perhaps once new cases are able to be made, I'll have the inside of the Activision case changed to the Atari brand, that way Atari brand PCB's will fit.

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I am in the process of building an EPROM burner to start creating my own carts. The schematics I have will handle a 2732, but I can't find them. I do, however, have a lot of other chips, 27128, 27256 and 27512. Is it possible to use these in the creation of Atari carts? Like, only burning the first 4k of them? I also want to make some 8k games. What about using them for that? Another idea that comes to mind is Multi-carts. How is an EPROM burned for those? Thanks!

 

Ian Primus

ian_primus@yahoo.com

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Junie,

 

I just wanted to put in my 25 cents on your project ideas. I think the custom boards is a great idea, and if you can make them, go for it.

 

My experience has taught me so far, after my very limited run of Polo carts and the whole Atari debacle (in another post), it was just easier to take ten of my ugliest, most common carts and make them anew. In some way, its my belief the cartridge is fulfilling its destiny. Ok, at the risk of going existential, if the cart is ugly (like a beat up old car) rebuilding it to a prized condition and making it the center of attention again is sort of like "hot-rodding" the game. Of course, no one is going to diminish the available ones on the planet appreciably, considering the vast numbers that were created 20+ years ago.

 

As for eproms, I have been working on 25 year old arcade machines for years, and have never once seen an erased eprom. They commonly have dirty connections, but rarely is the data corrupted. I just use little colored label stickers over the window, and make sure I write the program a few times to the chip, resocket it and check the checksum before I make it into a cart.

 

Just for fun, here is a shot of the remaining Polo carts. Thanks again to everybody who helped me make these. It was fun and challenging. Now to figure out F8 better than a rats nest.....

 

polo2.jpg

 

Cassidy

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I might make custom PCB's in the future, only 4K as I know nothing about making the bankswitching. I would have them done commercially though I wouldn't make them, this would insure high quality and be made for about the same price without me having to spend so much time and effort on it when I don't have to.

 

If I ever do make PCB's it will because no one else offers them, for example Activision PCB's-- Or perhaps I would make the Atari brand PCB as well if I ever sell large amounts of games from my publishing service to help lower the cost for game authors.

 

I highly recommend that everyone buy new custom 4K Atari brand PCB's from Joe Grand. He is a great guy and offers them in discount buying depending on the quanity that is ordered. You can buy PCB's from Joe for as low as $1.00 each.

 

[ 02-17-2002: Message edited by: Junie ]

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