How to load a ROM onto a cartridge

[Ulfhedhin]

How can I load a ROM onto a cartridge? I'm assuming the old one would have to be erased so the new one could be loaded. So far the only lead I've found was a now defunct site www.pixelspast.com where I could get a board to put the ROM on. But if someone can point me in the direction of another place to get those and how to load them, then I won't have to try to sacrifice an original .

[Wickeycolumbus]

There are a number of ways to do this. AtariAge offers custom cartridges here. Then there is the Harmony cartridge, which can load games off an SD card. You could also go the EPROM programmer method which would consist of burning the ROM onto an EPROM and either modify an existing cartridge to use it, or get a new PCB that was designed to work with EPROMs.

[+nanochess]

As Wickeycolumbus says, the easiest ways are the Atariage custom cartridges or the Harmony cartridge.

 

If you want to bite the bullet you can manufacture your own PCB using designs available in the Internet, besides you'll need an EPROM programmer, an EPROM eraser (if you want to reuse memories,) a GAL programmer (for banked carts) and of course soldering skills.

 

Please note that in cartridges were used mask ROM memories and these aren't erasable nor pin-compatible with common EPROM.

 

Myself I've made a banked homebrew cartridge for my game Space Raid but it took me at least two weeks to build it mostly because of wiring problems. For cartridge entry I've used (destroyed) a Pigs in Space PCB.

Edited December 1, 2013 by nanochess

[Wickeycolumbus]

Awesome cartridge, nanochess

 

Beware of wire length in future projects, those look sort of long. If they are too long, the circuit may not work even if it's wired correctly because of the high frequency signals. I've been bitten by that before, it's not fun.

[Ulfhedhin]

Right now, speed is of the essence. I came up with an amazing idea for a Christmas present so I am trying to figure out what I can as fast as I can . If a process of wiping an existing cartridge and loading a game onto it is a (relatively!) fast processes, I'll go that route. To be honest, this idea of mine has shown me all kinds of cool stuff that are done with Atari ROMs, how new games are made, etc. and if I weren't pressed for time, I'd try to sort through this myself. But since I'm pressed for time, I'm trying to get it done ASAP. But after this, I think I'll delve into this. It looks like fun . I'm an aspiring game programmer (C++ and C#) and have learned quite a bit. But I think I'm going to try my hand at this as well. Reminds me of my childhood .

 

I saw the custom cartridges (after I posted my message, naturally...and after quite a bit of searching!) from here and I've put it down as an option if the above possibility can't be pulled off in time.

 

Newbie question...what is an EPROM? Is that what would be loaded onto a new board? Or is that reserved for wiping and reloading preexisting boards?

 

EDIT

 

Also, I saw the Harmony cartridge and think it is AWESOME. But for this particular project, it isn't what I'm after.

Edited December 1, 2013 by Ulfhedhin

[raindog]

An EPROM is an erasable, programmable ROM chip. Usually you erase it with UV light and there are EPROM programmers you use to burn a new ROM image onto them. As nanochess said, they're not compatible with mass-market Atari cartridges which used non-erasable, mass-produced regular (mask) ROMs.

 

But I'm afraid, if you didn't already know what an EPROM is, that you might be in over your head if you're trying to get this done by xmas. You might be able to get a game up and running with Batari BASIC by then, or you might be able to learn how to burn ROMs by then, but if you have any kind of job and/or life, both of them together might be too much to pull off in 3 and a half weeks.

[tokumaru]

If a process of wiping an existing cartridge and loading a game onto it is a (relatively!) fast processes, I'll go that route.

You can't "wipe" an existing cartridge. Official cartridges use mask ROMs, which are manufactured with the game program already inside them, they're not (re)programmable. PROMs, EPROMs, Flash ROMs and EEPROMs, on the other hand, can be programmed (all but PROMs can be erased and reprogrammed). So if you do decide to use an existing cartridge, you'll have to remove the mask ROM and solder a programmable ROM in its place, after you have programmed it with the software you want using an EPROM programmer (the cheapest ones cost around US$50, AFAIK). Note that some cartridges don't have desolderable ROMs (the mask ROM may be inside an epoxy blob that can't be easily removed), and that some pirate carts use EPROMs which can be erased and reprogrammed.

 

What exactly do you plan on putting in the cartridge? Are you planning on programming something yourself? If so, I have to agree with raindog, your time frame is pretty tight if this is a software + hardware project and you don't already have any knowledge in either area.

[Ulfhedhin]

I already have the project ready to go. It is a modification of the ROM of my mom's favorite game. The only modification I made was to display, "I love you, Mom" at the beginning. Beyond that, the game hasn't been touched. She recently dug out our old Atari stuff from when I was growing up and she was very hopeful that I could get one of the two consoles she had stored away working so she could play her favorite game (Megamania). I can't get those two "six-switch" consoles working (video is jumpy and staticy and can't figure out why) but I did manage to get an old "4-switch" console that I bought at a flea market over a year ago working (couldn't test it until I got the power and TV cables the other day). It is ironic that the console from the flea market works (even had some rust inside of it when I opened it up LOL) whereas the consoles my mom carefully stored away don't. But at any rate, she will be able to play her game now and I had thought to set that up for her for Christmas. Then I had the idea to mod the game to tell her how much she means to me with a surprise message.

 

I have two Megamania cartridges and I'd hoped to be able to "wipe" one and replace the ROM with my modified one. But since you guys said that isn't possible, it looks like I have two options. Somehow get the ROM loaded onto an EPROM and then see if I can place it in one of the cartridges so it looks original (thus adding to the surprise) or go with the custom cartridges offered here at Atari Age. At any rate, one of these options looks easily doable before Christmas . Does this help?

 

The more I read about this stuff, the more motivated I am in really diving into it, learning to program/create these games, repair the consoles, etc. I've been teaching myself programming for the past few years and have recently gotten interested in the electronics/hardware side of things.

 

EDIT

 

And for my future reference, can someone recommend an EPROM programmer? I have a feeling I'll be getting into this and a recommendation will definitely help versus me picking one blindly .

Edited December 1, 2013 by Ulfhedhin

[+nanochess]

Awesome cartridge, nanochess

 

Beware of wire length in future projects, those look sort of long. If they are too long, the circuit may not work even if it's wired correctly because of the high frequency signals. I've been bitten by that before, it's not fun.

 

Thanks! Indeed it works although it took me a whole week to repair all soldering defects because of too thick cable.

 

Newbie question...what is an EPROM? Is that what would be loaded onto a new board? Or is that reserved for wiping and reloading preexisting boards?

 

 

An EPROM is an erasable memory, you'll recognize it because it has a transparent window over. And yep, it is for using in a new board. So you can erase it to reprogram it.

 

None of the chip in Atari boards can be reused. It looks like Double Dragon uses EPROM and can be reused, but I don't have one to verify.

[+nanochess]

And for my future reference, can someone recommend an EPROM programmer? I have a feeling I'll be getting into this and a recommendation will definitely help versus me picking one blindly .

 

I've used this one, it's reasonable and small. http://www.mcumall.com/comersus/store/comersus_viewItem.asp?idProduct=4312

[tokumaru]

I have two Megamania cartridges and I'd hoped to be able to "wipe" one and replace the ROM with my modified one. But since you guys said that isn't possible, it looks like I have two options. Somehow get the ROM loaded onto an EPROM and then see if I can place it in one of the cartridges so it looks original (thus adding to the surprise) or go with the custom cartridges offered here at Atari Age. At any rate, one of these options looks easily doable before Christmas . Does this help?

Yeah, that's probably the way to go. If you end up damaging the label, you can always have a new one printed on adhesive glossy paper. If by any chance the original cart uses an epoxy blob instead of an actual DIP ROM, you can get one of Atari Age's boards and put it in the original shell.

 

And for my future reference, can someone recommend an EPROM programmer? I have a feeling I'll be getting into this and a recommendation will definitely help versus me picking one blindly .

If this is a one time thing, it would be better to just have someone program the EPROM for you (I'm sure most people would be willing to do it if you paid just the mailing expenses), but if you're serious about getting into retro game development, my main recommendation is that you get a true USB programmer. A lot of the cheap stuff uses USB for power only, and require a parallel port (which are nearly extinct nowadays!) for data transfers. The one nanochess suggested looks pretty decent. I own an older Wellon that has served me really well.

[Ulfhedhin]

I didn't see on the store here how to get the board all by itself, just the custom cartridge with the board inside. If I feel like I am going to damage the label in ANY way, I won't do it. I only want to do it if the label remains undamaged. And if that occurs, then I'll go for the cartridge/board package offered here. I'll check out the cartridges in a bit and see how feasible it is to open one of them.

 

For this one-time thing, yes, I'll have to figure out a way for it to be done for me (sounds like it will be through Atari Age here). The request for a recommendation is for any future projects I may want to tackle when I dive into this and give it the time/attention it needs . Do you have a recommendation for the "true USB programmer"? Would the link given by nanochess suffice?

[dwane413]

you can get one of Atari Age's boards and put it in the original shell.

Will an AtariAge board fit in an Activision shell? I have no idea, but wanted to bring it up in case it might be an issue.