A quick, 8-character checksum used primarily to detect accidental file corruption.
While Redump focuses on disc-based media (like PSP UMDs), the No-Intro project focuses on cartridge-based systems. For PSP purposes, Redump is the primary standard, but you will often see "No-Intro" mentioned in the same breath regarding ROM preservation.
Ensure your PSP is running a Custom Firmware (like PRO-C or LME). Connect your PSP or memory stick to your computer.