Apple 2513
2513 Character ROM (CGR-001 RO-3-2513) replacement for Revision 4 and older Apple II / II Plus and Apple 1 computers.
The ROM that has been used to flash these chips can be found here
For compatibility for Apple 1 computers, diodes have been installed on the PCB to cater for the negative voltages coming from the Apple-1’s IC 2519.
Take note of the orientation of the chip when replacing it.
I have also built a custom tester which reads and verifies the data on these chips (See last photo)
