Naturally, the parallel port version is non-bootable (lacks BIOS routing to the drive). The SCSI version can, if the SCSI adapter has BIOS support for it.
I have bad experience with most LS drives. I still have one in an external parallel enclosure - but to tell the truth, other than the advantage of slightly better speed with regular 1.44 floppies and reading weak sectors much better,
it is vastly inferior to a DVD-ROM or HDD in a parallel port enclosure, regarding both speed and capacity.

I don't think about it other than as external floppy drive. In my youth I had an internal version of LS-120 and didn't use it other than for reading/writing usual 1.44 floppies.

Does the parallel version work in DOS?

In that respect, it can serve very well. (except for the boot-up role)
Of course it does work in DOS, too. The only disadvantage is that you need to load the proprietary parallel port bridge driver.

Thanks.

You mentioned parallel port external DVD-ROMs. What is your experience with such? Do you have any particular model to recommend?

Well, whatever your bridge chip still supports. I have the OnSpec chip, which has trouble with modern drives that are not fully ATAPI compatible. I spent a lot of time searching my stockpile for a 2004 Samsung model - unfortunately I dont remember the exact type. Generally you will want a drive from before ~2006.

Jolaes76 wrote:

whatever your bridge chip still supports.

Bridge chip, what's that?

I mean the chip in the external enclosure panel that translates between the LPT and the IDE interface like

Arista ParaDrive products
DataStor Commuter disks
Fidelity International Technologies TransDisk products
Freecom IQ Cable Parallel
Shuttle Technology EPAT/EPEZ parallel port IDE adapter
Shuttle Technology EPIA parallel port IDE adapter