8mm data cartridges

How common were drives which could read these? I suspect the answer is "not very"! If anyone has one, how reliable was/is the media? I've got a couple of such Sony cartridges here dating from 1991; one does call itself a data cartridge (QG-112M) - the other one is a PAL/SECAM 90-minute Video8 tape (P5-90MP). Going from the labels, both have backups from some UNIX system on them - but (helpfully!) no clue as to what that system was or what backup program wrote them. From the huge box of floppies that I found them in though, I suspect that they might be from an Olivetti 3B2 - in which case they're possibly just tar dumps. I'm not sure what my chances are of finding a drive to read them are though (and worse still, such a drive might not be SCSI and so require a proprietary interface card and drivers). The packrat in me wants to try reading them rather than just tossing them out though :-) cheers Jules