Manuals / brochures etc. at least for the EP8000 did actually appear as a reply to a post on this very forum, 9 years ago!
https://www.vintage-radio.net/forum/...ad.php?t=77595 (Attached one brochure here, showing EP8000 in use as an EPROM-Emulator)
So it seems
http://matthieu.benoit.free.fr/ hasn't discovered these / had one yet to take photos of.
Although there is a small external photo of the EP8000 here:
https://stardot.org.uk/forums/viewtopic.php?t=2708
- Where someone looking for the manual eventually found them on this forum.
I did find this useful advert that shows the EP8000 is really an enhanced EP4000, that supports larger-memory devices and can also run checks for shorts etc. on the device pins:
https://worldradiohistory.com/hd2/ID...-Page-0021.pdf (also attached a copy of this)
- Which also does now list the BP5 Signetics Bipolar PROM add-on, showing it is suitable for both the EP4000 & the EP8000 units.