Recalbox does not share usb, however there is a fix:
https://github.com/recalbox/recalbox-os/wiki/[4.1.0]-Sharing-a-external-usb-hard-drive-on-samba-network

@paradadf if he meant "unload the roms from the usb key to the sd", then nope there is no easy way for that

@substring
That link did not work but I found it anyway. Seems to happen at random so might take some time befor I report back.

@xanarkan oui il s'agit d'une feature arm/neon only.
L'ajout de nouveaux cores, dont le mednafen psx est prévu. Mais nous avons d'autres chantiers "techniques" à terminer avant de nous lancer la dedans.

@realazyria read the fullscrape post, or ask paradadf for the fastscrape version

@alexandre-leme-checchia what version of recalbox do you have?
I'd try with FAT32 if I were you.

thanks a lot for confirming!

I went and checked again, and there were a couple of games that the reference to the bin file was .bin not .BIN. But editing them did no good and the games that had the extension in caps still worked in my internal memory. I know the bios files are there because I get the menu for the CD player for Sega CD and it will play music tracks from the game. It has to be something other than the .bin file extensions causing the problem.

I didn't get how were you trying to access the SD Card, but I'd recommend you to use read the wiki/manual.
Manual (EN) - Network features

Windows can't read the share partition, where you are suppose to copy your roms.

I'm trying version as we speak.  After selecting my hdd in the settings menu it reboots and after that it got stuck on the black recalbox screen.  It's been there for about 10 minutes.  How long does it take to boot and is this every boot?

It also depends on if you're using a filesystem capable of compression.  If you are, you can use a smaller card and still hold a lot of data.  It's like putting your entire filesystem in one big zip file.

Es os emulation station the frontend. The noob partitions you see on your pc have nothing to do with the system you cant see remaining space from there.

I use a 64GB card.  To use the whole card I did the following: Use 'MiniTool Partition Wizard Free' (Windows) Delete all partitions on the card. Create a new partition selecting 'Primary' and 'Fat32'. You then have a 64GB (or there abouts) Fat32 partition and can copy the Recalbox files onto it. When Recalbox has installed you should have 57GB of free space for your Roms.