I've always found my drives (SCSI ... seagates usually) have
a small jumper for write-enable or write-disable and the
factory default has it writeable (of course).
I've fed a small set of wires out the side from that jumper
to a small SPST switch. You don't have to do all that wierd
stuff I do ... you can just put the jumper in place or take it
out (whatever) to have a read-only drive.
So, for SCSI solutions ... you can look for drives that have
a hardware jumper. No dangerous snipping of lines. It's also
undoable (open case, remove/add jumper, close case).
I've also fed out the remote LED jumper so I can see the blinky
lights :) Creeping featurism.
> Hokay, for MFM, RLL, ESDI, & SCSI, there is a separate WRITE ENABLE line
> on the cable. All that is necessary for a "read-only" drive is a pair
> of nippers, soldering iron, bit of wire, a 50k resistor, and a SPDT switch
> (must terminate the drive side of the line when open to keep it from floating).
> IDE is a *lot* more difficult because the controller is on the drive so there
> is no specific write enable line, rather it is commands that must be blocked
> and that takes electronics, I know of a few such devices but they have been
> in the U$200-U$300 range.
> However, to me the key is that you do not really need or want a mechanical
> drive spinning in there constantly at all. Green machines have power down
> when not needed. Floppy, tape, and CD-Roms run only when active and IMHO
> are all you really need. Save U$200 and skip the hard drive.