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MegaDrive/Genesis writable cartridge

Posted: Thu Jun 06, 2013 9:50 am
by eslime
Hi,

I'm reading this forums a lot of time and finally I created an account! :)

I'm an independent developer from Spain, and I'm trying to develop a MegaDrive/Genesis game using SGDK. All works fine, but I'm planning to launch a "cartridged" version of the game, and my question is about it:

Does anyone know a empty/writable MegaDrive cartridges supplier? I googled a lot, but I can't find any website/supplier of cartridges. I'm not interested on expensive cartridges with SD Card slot or similar, only a PCB extremely similar to the original MegaDrive PCB's...

Thanks for your help, and best regards! :twisted:

Posted: Thu Jun 06, 2013 12:39 pm
by frederic
Hi eslime,

Take a look at this thread: viewtopic.php?p=14849.

Posted: Thu Jun 06, 2013 3:20 pm
by nolddor
eslime Como bien te dicen ahi, la gente de WM Team se ofrecía a publicar juegos hay otros sitios web con el mismo proposito.

Quizas 1985alternativo.com te puedan hechar una mano, ellos hace poco han sacado el Oh Mummy Genesis! y ahora andan con un nuevo proyecto Antarex y los cartuchos y todos los hicieron ellos aunque la calidad del plastico no era ni por asomo comparable con WM Team.

superfighter.com también realizo en su dia el Beggar Prince entre otros juegos asi que es otra posibilidad a barajar.

Posted: Thu Jun 06, 2013 6:29 pm
by Chilly Willy
You can get the Tototek MD-Pro flash cart in bulk really cheap. If you're just looking for a small quantity, that might be the best. If you need larger numbers, contacting Fonzie may be the way to go.

Posted: Thu Jun 06, 2013 7:09 pm
by eteream
..

Posted: Thu Jun 06, 2013 9:04 pm
by sega16
eteream wrote:If you are only interested in the pcb... design it yourself! It's as easy as connecting most pins of the rom/eprom with the cartridge connector. Then send the design to a qualified shop.
That is what I am doing and in fact I made a sst39sf040 programmer using an arduino uno and 3 74hc595. The sst39sf040 (cost $2 in single quantity at digikey) is cheaper than some eproms and does not need 12v only 5v and it is still in production and it does not need uv light to erase. Here is the wiring: Pin refers to the numbering on the arduino uno. The D0:D4 to go A0 to A4 D5:D7 go to Pins digital pins 5 to 7 Pin 11 CE# Pin 12 OE# Pin 13 WE# Pin 10 is the serial strobe for the shift register this must be connected to all 3 shift registers Pin 9 is the storage register this also must be connected to all 3 shift registers. Pins 2,3 and 4 is the serial output pins 2 is the LSB. Unlike pin 9 and 10 those are different per each shift register. A0:A18 goto the output from the 3 shift registers. Make sure you have which one is LSB and MSB right. I will warn you that this can get messy as there are lots of wires be careful and check your work. My program verifies every byte if you see any errors check your wiring. Here is the part that runs on the arduino uno https://github.com/ComputerNerd/sst39sf040-avr Note that I used avr-gcc instead of the arduino IDE to compile this if you do not have avr-gcc it can be modified with ease just change int main() to void setup() and add void loop() {} at the bottom of the program and I think it will compile just fine in the arduino IDE. And here is the part that runs on your computer I have only tested it on linux but I used a cross platform library so it may work on windows https://github.com/ComputerNerd/sst39sf040-computerside Also my code can be easily adapted to run on the very similar lower capacity chips. The sst39sf020a and the sst39sf010a. Just change the main for loop to run for less bytes. That should get you started but note that you will need 2 flash chips per cart as they are 8bit but an advantage of that is that you can have double the capacity.

Posted: Mon Jun 10, 2013 10:32 am
by KanedaFr
It was my main goal when I bought a teensy : LOW cost USB writeable cart

You approach is really interesting since it uses few components ...
If you could give us more details (for totally newb), it would be great ...
I could host files for a tutorial if you need to...

Posted: Mon Jun 10, 2013 1:23 pm
by sega16
KanedaFr wrote:It was my main goal when I bought a teensy : LOW cost USB writeable cart

You approach is really interesting since it uses few components ...
If you could give us more details (for totally newb), it would be great ...
I could host files for a tutorial if you need to...
My programmer is made to program parallel 5v flash. I have only tested it with the sst39sf040 although it should work with other flash chips with slight modification. The microcontroller in this case the avr (arduino uno) it directly controls the data pins and the CE# WE# and OE# pins. All address lines are handled by shift registers note that in future versions I will replace the shift registers with the mcp23s17 as most microntrollers have hardware spi and this will increase performance. Once the port expanders arrive I will add support for that but leave in support for shift registers if that is all you have. Also I bough a 64 pin card edge connector so my ultimate goal is to make a device where the flash chips are on the cart and by inserting the cartridge into the programmer it will program with ease. As for the computer side It just does some handshaking and reads the manufacturer and device id. Then it sends the first byte and waits for the microcontroller the send the byte back if the byte is different there is an error. If you need more details please ask I am not sure what needs to specified.

Posted: Mon Jun 10, 2013 1:42 pm
by KanedaFr
It seems you exactly plan to make what I only "virtually" made for now :
http://gendev.spritesmind.net/wip/2011/ ... perwriter/
(OMG! 2 years old !!!)
usb -> spi/i2c -> expander -> cart with ram/rom and sram or not

I personnaly understood what you explain but for someone new on this one (or on electronics), a schematic is always great ;)