The VS 15 is part of the CP5 processor family and can support up tp 16 users. It has a 16-bit memory bus and a 16-bit I/O bus.
Mike and Warren tried booting the VS 15 that had a 147 MB disk in the base. The system reported lots of errors during the boot process. Cleaning the card edge connectors, reseating the ICs, etc did not help. It almost booted once, but displayed an error code that said that boot files were missing. We moved the disk to the other VS 15. This one is nearly spotless inside and passed boot diagnostics on the first try. It also displayed an error code relating to missing files.
Connect the disk to the VS 65 and find out what files are missing, and replace the files.