The simdisk is a 'disk simulator' card in the card cage. It is the full length card with no wires plugged into it.
The simdisk card has several functions:
1. It has a chip that interrupts the cmos boot sequence and re-assigns drive letters to the memory chips on the card.
2. The twelve ROM chips with the labels. These are the A:\ drive and have been burned to contain the operating system and the control software.
3. There are four, eight, twelve, or more RAM chips that are the B:\ drive. The a:\shell.exe can format the drive as well as setting the paths and other things. The B: drive has the RAM directory with the parameter files and the PARTS directory has the part programs.
The floppy disks you have are likely back-up copies of the RAM directory.