We should probably have a new metric for measuring mass storage performance: bytes per pound. An old IBM tape drive from the S/360 days, for example, could hold almost 6 megabytes of data. It also weighed more than a typical refrigerator. Today, a tiny postage-stamp-sized card can hold gigabytes of data and weighs — at most — a few ounces. Somewhere in the middle is the old 8 inch floppy drive. At its peak, you could cram about 1.2 megabytes on it, but even with the drive you could lift it all in one hand. These disks and their descendants ruled the computing world for a while. [Adrian asks the question: can you use an 8″ floppy drive on a PC? The answer is in the video below.
He didn’t do it on a lark. [Adrian] is getting ready to restore a TRS-80 Model II so he wanted to create some 8″test floppies. But how do you marry a 40-something-year-old drive to a modern computer? He had a few drives of unknown condition so there was nothing to do but try to get them working.
The 8 inch floppy connector isn’t even the same as a 5.25 inch connector which PCs do support. However, electrically, the drives are the same, so if you can make the mechanical connection, a conventional floppy controller will do the job.
Been a while since we’ve seen a big drive like this. We had forgotten that the spindle motor ran on AC wall current and required a start capacitor. Some surgery on a donor cable from an old word processor made the connection. Sure enough, the BIOS on a PC recognized the drive, although the geometry for a disk like this wasn’t in the BIOS choices.
A long video, but fun to watch those giant old drives working and [Adrian’s] process of working through his issues. Of course, these days, you can read a floppy with a Raspberry Pi or — for the stout at heart — try an oscilloscope.