The Durango F85 was an early office computer based around a 5MHz 8085 processor, sold in 1977. It had an impressive 64kB of RAM, upgradable to 128kB, and ran its own multitasking operating system call DX-85M, as well as CP/M. It had an interesting electric-typewriter form factor, with a little monitor sitting on the side of it --- in operation you were facing the 14" printer.
It was touted as being portable. Which it was, if you were strong; the story is that they had to do an extensive search to find someone capable of lifting it for the following photo...
...and even then, only for a few seconds.
It used 5.25 soft-sectored disks storing an impressive-for-those-days 480kBish on a side, using a proprietary 4-in-5 GCR encoding. They used 77 tracks, 12 sectors and 512 bytes per sector. Later models used double-sided disks; I don't have access to an image of one so don't know how they work (there's a suspicious looking spare byte in the sector header which could store the side). As always, if you have one, please get in touch.
Just do:
.obj/fe-readf85
You should end up with an f85.img which is 472064 bytes long.
There's amazingly little information about these things.
- Chuck Guzis' F85 page with lots of pictures