It is the primary system ROM chip (IC501) for the Dreamcast console.
This review focuses on the mpr-21931.ic501 BIOS file specifically as it relates to the emulator for Sega Dreamcast and arcade systems like NAOMI. The "Repack" Solution: Solving the MPR Error One of the most common hurdles for users setting up the DEmul emulator demul mpr 21931 ic501 repack
: This is actually the file 1_01d_01.bin (CRC: 89F2B1A1 ). It is the primary system ROM chip (IC501)
One of the most confusing and specific error strings you might encounter is: go to display settings
Open the panel, go to display settings, and confirm the refresh rate is 60Hz, not 30Hz or lower. Setting Up Controls
If the game runs, but with severe stuttering or in slow motion, it is likely a refresh rate issue: