Flashing a custom Genesis Cartridge PCB with new software

For hardware talk only (please avoid ROM dumper stuff)
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db-electronics
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Flashing a custom Genesis Cartridge PCB with new software

Post by db-electronics » Tue Aug 11, 2015 12:43 pm

Hey guys, just wanted to show everyone a video of my MDCarts and how I write a ROM to them.

https://www.youtube.com/watch?v=wEq0AQl5xTw

FYI the current cartridges specs are:
-2MBit, 4MBit, 8Mbit and 16MBit
-all 5V flash, no 3.3V non-sense
-32KB Battery-backed SRAM, or 32KB FRAM
What does db stand for? Well that's an excellent question...
http://www.db-electronics.ca

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BigEvilCorporation
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Post by BigEvilCorporation » Mon Aug 24, 2015 12:21 pm

Hi db!

I've been eyeing up some EPROM writers on eBay recently so this post comes as a very pleasant surprise.

My goal was to follow this guide: http://www.epforums.org/showthread.php? ... nesis-Cart to replace the chips on a bunch of £1 sports carts I got from a local retro games shop (most game shops that sell Mega Drive games will have a stash of these things they can't sell!).

I've been looking at these:

http://www.ebay.co.uk/itm/TL866CS-USB-U ... 419ab660bb
http://www.ebay.co.uk/itm/EPROM-16bit-A ... 1c397b506b

Do you reckon this is the right way to go? I have enough soldering skills to replace a chip, but neither the skills nor hardware to create my own blank carts like you've done.

This is a hobby project for testing my own homebrew games so cheap and cheerful devices are preferred over industry quality (I was pleased to see you're using a cheap USB model in the video), I won't be running off 100's of these things.
A blog of my Megadrive programming adventures: http://www.bigevilcorporation.co.uk

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Post by db-electronics » Tue Aug 25, 2015 12:14 pm

If you're replacing chips on old sports carts then you'll need to make sure that whichever EPROM writer you select can support 40 pin and 42 pin memories. Furthermore, these sizes generally are UVPROM and so if you will need to re-write them a few times you will also need a UV eraser.

Conversely, if you wait a bit longer I will have a cart reader/writer available based on Teensy++ (Arduino compatible, therefore easy to program for) which will be open-source.
What does db stand for? Well that's an excellent question...
http://www.db-electronics.ca

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BigEvilCorporation
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Post by BigEvilCorporation » Wed Aug 26, 2015 9:08 am

db-electronics wrote:if you wait a bit longer I will have a cart reader/writer available based on Teensy++ (Arduino compatible, therefore easy to program for) which will be open-source.
That sounds the better way to go, seeing as I don't really know what I'm doing! I look forward to it :)
A blog of my Megadrive programming adventures: http://www.bigevilcorporation.co.uk

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HardWareMan
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Post by HardWareMan » Wed Aug 26, 2015 2:56 pm

Passive adapter for Arduino:
Image
Image
Image
It takes 1:39 for a 3MByte dump, and about twice time for write this volume.
Image

Also same technique for FC cartriges:
Image

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Post by db-electronics » Wed Aug 26, 2015 3:06 pm

Yeah it seems everyone if off doing their own thing. But it's not enough to simply do it on your own at home, you've got to make your solution available to others, provide open-source software. That way everybody starts using your solution and we slowly standardize instead of having a million different solutions.
What does db stand for? Well that's an excellent question...
http://www.db-electronics.ca

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Post by KanedaFr » Wed Aug 26, 2015 7:31 pm

On my case (http://gendev.spritesmind.net/wip/2011/ ... perwriter/), nothing is available because I never found the time to finish it.
Code is not tested enought and hardware design is v0.

but as usual, I'm ready to share what I have done to anyone asking for it.



If you want open hardware, don't forget Bruno's version:
http://www.brunofreitas.com/node/42


but we already talked about this (HW too, sharing his code) on this topic:
viewtopic.php?t=1899

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Re: Flashing a custom Genesis Cartridge PCB with new software

Post by db-electronics » Fri Aug 28, 2015 3:53 pm

Wow seems like Bruno and I independently came up with almost exactly the same hardware!
What does db stand for? Well that's an excellent question...
http://www.db-electronics.ca

bastien
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Re: Flashing a custom Genesis Cartridge PCB with new software

Post by bastien » Sat Aug 29, 2015 1:41 pm

i have also made my own Flashcard with an FPGA and 8Mo Flash memory + RAMTRON for storing save

Image

HE10 bus is here for debug and add extra stuff.

complete source and code is here :

https://code.google.com/p/xflash64/

and shematics is here:
http://sega4ever.power-heberg.com/FPGA/ ... 4_Rev0.pdf

Video First Test with Sonic 2
https://www.youtube.com/watch?v=LkB7F0W ... iA&index=4
Video 8 Mo rom test
https://www.youtube.com/watch?v=OycKK8q ... iA&index=2

and i have made a C++ Qt gui for command it ( it launch Quartus II CMD prompt with correct param)

Image

it don't need an external programmer it works with USB-JTAG and Altera Nios 2.
when rom are flashed into memory the correct configuration is flashed into the EPCS memory for FPGA.

my projecst can be found in my Oshpark profile with MD PCB clone too ( maked for regular Eprom 27C160 and 27c322)
https://oshpark.com/users/current

https://644db4de3505c40a0444-327723bce2 ... D4TZ/i.png

but UMDK is a better and faster solution than my project so i have keeped that for me. 8)

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