Ic501 __top__ | Demul Mpr- 21931.

Create a folder named inside your main DEmul directory. Place your BIOS files inside a zip archive named dc.zip . Put that dc.zip directly into your ROMs folder. 3. Update Emulator Paths

Without this file, DEmul cannot initiate the system's "handshake" process, resulting in a startup crash or an error pop-up. Why the Error Occurs The error usually stems from one of three issues: demul mpr- 21931. ic501

It specifically corresponds to BIOS v1.01d , released around 1999. Create a folder named inside your main DEmul directory

Look for a file with CRC 5454841F . This is the earlier v1.004 Japanese BIOS. 2. Proper Folder Structure DEmul is picky about where it looks for these files. Look for a file with CRC 5454841F

The emulator might be looking in the wrong directory for your BIOS files. How to Fix the Error

You may have the correct BIOS data, but the file is named generically (e.g., dc_bios.bin ) instead of the specific format DEmul expects.

Look for a file with CRC 89F2B1A1 . This is the v1.01d BIOS.