RetroGameGirl

Rebooting the past, one byte at a time.

Modifying an Atari 7800 Cartridge for a Custom ROM

Modifying an Atari 7800 cartridge to fix a bug is a hands-on process known as ROM swapping. This is how you take a game file from your computer and physically install it onto the original hardware.

The process begins after you have the final, bug-free ROM file ready to go. You transfer the data from your computer to a new, blank EPROM chip using a specialized device called an EPROM programmer. The programmer, with the chip inserted, is ready to be “burned” with the custom ROM.

After the chip is programmed, the next step is the physical swap. You’ll need to carefully open the cartridge and, using soldering tools, desolder the original ROM chip from the circuit board. It’s a precise task to avoid damaging the board. Once the old chip is removed, you then solder the new, custom-burned EPROM into its place.

With the new chip securely in position, you can reassemble the cartridge and test it.

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