The original dump at offset 0x2100 contains the waste counter. The original firmware calculates a Fletcher-32 checksum across the entire EEPROM range 0x1000 to 0x2FFF .
| Offset (example) | Original Value | Patched Value | Effect | |----------------|----------------|----------------|--------| | 0x1F4 | 5000 (pages) | 0 | Resets page counter | | 0x2A0 | FF (ink full) | 00 (ink empty forced) | Allows refill detection | | 0x300 | 100% waste pad | 0% waste pad | Removes "Service Required" | | 0x500 | Region: JP | Region: US | Allows different cartridge types | eeprom dump epson patched
For the savvy technician with a CH341A programmer and a backup of their original dump, a patched EEPROM is the difference between a $500 printer becoming e-waste or running another 10,000 pages. The original dump at offset 0x2100 contains the