Re: "an Ohio Scientific Instruments Challenger 8P"
Wow, someone else actually bought Ohio Scientific! My first personal computer was an OSI C4MP --- 6502 processor, something like 16KB of memory, and a 5.25" floppy.
Sort of an Apple II alternative, but OSI's attitude was that they built the hardware, the OS was your problem. As in, create a disk file by first loading the monitor routines from the system floppy, using it to manually allocate as many sectors on the target floppy as you expected the file to need, then load the editor from the system floppy, edit the file (typically in BASIC), swap the target floppy back in and save the file to the disk. If you got
cheapthrifty and allocated too few sectors, nothing for it but to discard all your work, de-allocate the file and start over with more sectors.
Double-sided floppies? Cut a read/write notch on the other side, and put the floppy in the drive upside-down.
Old phart icon, 'cuz that was in the 1970s.