CRONIC for sure. On a HSC40 or 50 the boot media would
be a DEC tape,
can't remember
the model, have a '50 or two with them. The floppy bootable versions
started with the HSC70.
The HSC50 was the earliest model, and the ONLY model that used a TU58
tape cartridge to boot.
I have boot media for the HSC50 not sure if it's
compatible with the HSC40
though.
No, it will only work on the HSC50.