I was able to successfully load my old game saves into PCSX ReARMed and relive some old gamer memories. Here are roughly the steps I undertook to get this going. Hardware Used: PC, PS3, USB Memory Stick for both PS3 and PC, PS3 Memory Card Adaptor

Get RetroArch Going

1. Head on over to RetroArch’s website, download the program and install or unzip it.
2. Download the “Sony - Playstation (PCSX ReARMed)” core
3. Grab your desired PS1 Disc and use RetroArch’s Dump Disc feature to store your disc locally and relieve of it of its spinning duties
   1. Check your RetroArch’s downloads folder to confirm files and their sizes. You should see 1 cue and 1 or more bin files with names that represent a timestamp of when the dump was started
   2. You may rename these files and if you do, make sure to edit the cue file with any text editor to refer to the renamed bin files.

Grab your Save Data via PS3

1. I performed some of these steps years ago but basically, you would need to use a PS3 Memory Card Adaptor to copy your save data from your PS1 Memory Card to your PS3’s HDD. This process is documented on PlayStation.com’s Help Library. 
2. Stick a USB memory stick into your PS3 and copy your desired game’s save files over. Unfortunately, I had to do them one at a time and couldn’t figure out a way to copy multiple saves at once.
3. Safely remove the USB memory stick and plug it into your PC that’s running RetroArch. You should see a PS3\Export folder structure with a bunch of PSV files.
4. Keep them handy for the next step

Convert your PSV

1. Search for download Shendo’s MemcardRex and download it from a reputable source. It is also available on Github but there are no releases so you’ll need to build it.
2. Run MemcardRex and in a new Memory Card tab, import one game’s PSV file(s) into a free slot. I specify one game because RetroArch creates and uses a unique save file for each dump it runs. To efficiently mimick this, we’ll need to use MemcardRex to save one memory card file for each game.
3. Hit the Save button and choose (*.mcr) as your save file format. The file name needs to match the name of your disc’s image file. 
4. If you have multiple game saves, make a new Memory Card tab, import another PSV and save out the MCR. Repeat as many times as needed.
5. Next, you’ll need to change the file extensions from MCR to SRM.
   1. If you have many MCR files, you can use a batch renaming tool or a simple command line argument like “ren *.mcr ???.srm”
6. Place these files in your RetroArch’s saves folder. Alternatively, you can run your game once, identify the created SRM file and replace it with the one you made.
7. Run your game with Load Content and verify that the save data can be accessed and loaded.
8. Optional: back up your PSV and SRM files.

It’s a few steps but if you’ve spent hours playing a game, the save data represents actions that were made, memories that were created and time that was spent. It is valuable.