King's Quest V was an interesting beast. There was SRAM on the cartridge, but no battery. The developers included a save feature, but without a battery, it didn't persist across hard resets. Furthermore, they added code that clears out the SRAM upon a cold reboot (presumably to prevent partially-corrupt saves from being loaded after rapid power cycling). For this hack, a few instructions have been changed to prevent the pertinent areas of the SRAM from being cleared upon a cold reboot, which allows emulators, flash carts, or reproduction cartridges to have a fully-functional battery backed save.
Database match: King's Quest V (USA)
Database: No-Intro: Nintendo Entertainment System (v. 20210216-231042)
File SHA-1: B8C9D7783CB9E39472F05E1655DA155D2C5B5630
File CRC32: A6C5CBD8
ROM SHA-1: A39BCDAED0DFFDEC5E3FBECA39FE95D62CBDDA8A
ROM CRC32: 837960