: Windows may warn you about changing extensions; click Yes . Method 2: Using MemcardRex (Advanced/Multi-Save)

allow you to upload your save and convert it directly in your browser. Top Tools and Software

If renaming doesn't work or you need to manage individual save blocks, use MemcardRex , a dedicated memory card editor. Open the file : Launch MemcardRex and go to File > Open . Select your source file. Export/Save As

It sounds like you’re looking for a way to convert (typically Minimum Cell Rate in networking/ATM) to MCD (less standard; possibly Minimum Cell Delay , Maximum Cell Delay , or a typo for MCR to MCD in a specific hardware context like traffic shaping).

While manual renaming works for most, several tools automate this for bulk libraries: GDX-X/sd2psx-save-converter - GitHub

This format is primarily associated with the Bleem! emulator or Sony’s own PlayStation ecosystem (including the PS3 and PSP virtual memory cards). In some cases, specialized hardware like the DexDrive also uses variations of the .MCD extension. Why Convert Your Save Files?

The future: converters as first-class citizens As systems multiply and longevity of infrastructure becomes a business imperative, converters evolve from one-off adapters into robust, versioned, and governed services. They will increasingly embed policy controls, AI-assisted semantic reconciliation, and machine-checked guarantees about what is preserved or transformed. In short, the MCR-to-MCD converter is emblematic of a broader shift: engineering that values graceful interoperability over brittle replacement.