Those videos by CuriousMarc are
here. They are really useful if you are restoring an HP85.
As far as storage is concerned there are a couple of solid state drive projects available, using small processors and an SD card.
http://www.dalton.ax/hpdisk/
http://www.qsl.net/in3otd/electronic...PDisk_OTD.html
https://github.com/magore/hp85disk
But I am still struggling to get my HPDisk to simulate the older disk drives the HP uses. The protocol changed from "Amiga" to "SS/80" and only the latter types seem to be simulated reliably by HPDrive on an HP85, and the latter drive types require an extra (and rare) Extended Mass Storage ROM.
For those really interested in keeping these machines working well, in fully expanded form, there are also a couple of projects that simulate a range of very useful add-on ROMs on a single plug-in card.
http://vintagecomputers.site90.net/hp85/prm85.htm (By Bill Kotaska)
http://users.eastlink.ca/~phberger/86EPROM.pdf (By Paul Berger)