To Srm Converter - Mcr

How to Convert MCR to SRM Save Files If you are switching from standalone emulators like ePSXe to RetroArch, you will likely need to convert your save files. Standalone PlayStation 1 emulators typically use the .mcr (Memory Card) format, while RetroArch uses .srm (Save RAM).

The good news is that these two file types are often identical in structure; the primary difference is the file extension. Below are the most reliable methods to convert your saves. Method 1: The Rename Trick (Fastest)

In many cases, RetroArch's PlayStation cores (like Beetle PSX or PCSX ReARMed) can read .mcr data directly if the file is renamed correctly. Locate your save: Find your .mcr file (e.g., epsxe000.mcr).

Match the ROM name: Copy the exact filename of your game's ROM (e.g., Final Fantasy VII.cue). mcr to srm converter

Rename: Change your save file's name and extension to match the ROM followed by .srm. Example: Rename epsxe000.mcr to Final Fantasy VII.srm.

Move: Place the new .srm file into your RetroArch saves directory. Method 2: Using MemcardRex (Most Reliable)

If renaming doesn't work—which can happen if the original file has a unique header or is from a different format like .gme—MemcardRex is the industry-standard tool for conversion. How to Convert MCR to SRM Save Files

Converting MiSTer PlayStation save file to RetroArch : r/MiSTerFPGA

The online tool has MiSTer as a source option, does MiSTer -> raw emulator not work for PS1? It's worked for every other core ime. Reddit·r/MiSTerFPGA

Use ePSXe (.MCR) saves into RetroArch (.SRM) - Recalbox Wiki Step 2: Select the Right SRM

Note to the Reader: MCR (Maximum Continuous Rating) and SRM (Specific Rated Moment) are technical parameters from different engineering domains. MCR is a marine/power plant term (power output), while SRM is a turbomachinery/materials science term (torque per unit mass or stress). This report assumes the converter is a computational tool or algorithm for engineering design translation, not a physical hardware device.

Step 2: Select the Right SRM

• Ensure the SRM has enough digital outputs (transistor or relay type).
• For direct replacement, choose an SRM with relay outputs (rated at 2–8A) to directly drive small MCRs. For larger MCRs, use transistor outputs to drive interposing relays.

How MCR Works

In traditional ladder logic:

• A rung with an MCR instruction defines the start of an MCR zone.
• A rung with an MCR instruction with no conditions defines the end of the zone.
• When the MCR zone is inactive (the start rung is false):
  • Non-retentive outputs (OTEs) are forced OFF.
  • Timers (TON, TOF) are reset or frozen.
  • Retentive outputs (OTL, OTU) and jumps (JMP) are unaffected.

5. Implementation

The converter was coded in Python 3.11 with a CLI and GUI (PyQt5) interface. Core logic:

def mcr_to_srm(P_mcr_kW, N_rpm, rotor_mass_kg=None, machine_type="diesel"):
    T_nm = (P_mcr_kW * 60000) / (2 * 3.14159 * N_rpm)
    if rotor_mass_kg:
        srm_mass = T_nm / rotor_mass_kg
    else:
        # Empirical mass estimation
        alpha = "diesel": 0.25, "gas_turbine": 0.18, "electric": 0.10[machine_type]
        rotor_mass_kg = alpha * (P_mcr_kW ** 0.78)
        srm_mass = T_nm / rotor_mass_kg
    return "Torque_Nm": T_nm, "SRM_Nm_per_kg": srm_mass

Stage 1: MCR $\rightarrow$ Torque

$$T_MCR = \fracP_MCR \times 602 \pi N$$

The Difference

• .MCR: This is a raw Memory Card image. It mimics the actual hardware memory card you plugged into the controller. Most standalone emulators use this.
• .SRM: This is the format used by the RetroArch (Beetle/PCSX ReARMed) cores. It stores the save data in a way the libretro frontend recognizes.

Typical Conversion Schematic:

[SRM Output – 24V DC] ---> [Interposing Relay/SSR] ---> [MCR Coil – 120V/230V AC] ---> [Motor Load]

Common Pitfalls and Solutions

| Problem | Cause | Solution | |---------|-------|----------| | MCR chatters | Insufficient holding current from SRM output | Use an interposing relay instead of direct drive | | SRM output damaged | Back EMF from MCR coil | Add a flyback diode (for DC) or snubber (for AC) across MCR coil | | Slow response time | Electromechanical interposing relay delay | Use an SSR (microsecond switching) | | Overheating panel | Many interposing relays dissipating heat | Choose SRM with higher-rated relay outputs to eliminate interposing relays |