LTO.
Back in the nineties-2000 whilst being an educator at NSW TAFE, this storage size, longevity discussion was a regular in the mealroom. 286 386 486/dx2 etc Ram 4- 16Mb ram 3.5 & 5" FDD, 10-40 Mb HDD Omega drv floppy was the buzz (?). As we were required to weekly back up to magnetic tape which took forever and a lot of tape cassettes and safes in cool rooms etc. I remember jokingly offering my idea of using the helical scanning of a hot rod'ed BETAMAX video machine with high head speed and long record mode operating, write width of about 1.2 -1.5mm on a 2 ( low speed 4 hours) hour tape. I was jibbed at for even DARING to mention the betamax word, and was laughing told to try VHS and i rebutted with the old 60hz faster than 50hz chestnut and vhs max of 4 hours (8 hrs low qual).
Sony had introduced its PCM (digital) pulse-code modulation which straight away put it miles ahead of analog VHS and a candidate for digital data recording.
I recall sitting down and doing some calculation based on a tape length range of 40 Metres to 250 Metres @ βl and βlll recording speeds 1X & 3X respectively.
32bit's 40 Mts tape βl was about 30 Mbyte, βlll about 120 Mbyte; 250 Mts tape about 6.5 times capacity, (ie 190-750Mb ) These were astounding potential data storage capacities for the day and could have been made functional with enough $$ thrown at it, all from simple modification of existing equipment/ technology.
Please remember these were back of envelope/ coaster calcs based on standards and data from Sony and JVC. R/W Heads had between 2-6 magnetic coil heads for utilization and to play around with (6 head= 3, write read write read write read/ revolution). Head RPM and other variables, I think we played around with head speed of 50rpm -500rpm, 210mm/sec 2.1M/sec based on an 80mm(?) Video head ( from thinning memory). Print thru, moisture, temperature control, Cataloguing, time wasting process all problems, but 'LTO was the way to go'™ , Head RPM vibration, heat, other little problems to solve.
I expect to sit corrected and maybe flamed, but this was 25-35 years ago.
Oddjob
over