Back in the 1990s, there was a tool called ‘tripwire’ that checked key files against expected checksums.

As I recall, they recommended putting the expected values on a floppy disk and setting the ‘write protect’ tab, so the checksums couldn’t be changed.

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FuriouslyAdrift 3 hours ago | parent | next [-]

tripwire was the orginal file integrity anti-virus/anti-tampering software from the security group (which turned into CERIAS) at Purdue led by Dr. Eugene "Spaff" Spafford.

https://docs.lib.purdue.edu/cstech/1084/

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Terr_ 3 hours ago | parent | prev [-]

Back in the 90s I fantasized about a hard drive bay with a physical write-protect switch on the cover plate.

	▲	kqgnkqgn 3 hours ago \| parent \| next [-]
		In the mid-2000's I briefly worked for a company that did this at a firmware level ("write-blocked firmware") for USB drive adapters (IDE / SATA / whatever IDE variant laptops were using / etc). This was apparently very valuable for police and investigative services, so they could collect evidence, while being able to show that they did not tamper with the original drive.
	▲	kjs3 2 hours ago \| parent \| prev [-]
		Tenable makes some "read only" adapters for hard disks (SATA, PATA, SCSI & FW at least). They're usually sold as part of a forensic analysis kit. I have a couple and they definitely work. I believe there are a couple of other vendors (Wiebetech?) make similar devices. The alternative (tho not practical in many cases) would be RO media like RW-DVD.