After a bit of sleuthing on archive.org, I've found the trove of documentation on Arraid products back a number of years for arraid.com. I need SMD drives on my machines because the legacy OSes I run don't support MSCP, and I need large capacity (relative to RK/RL) disk. Now that I've acquired some of these AEM-1 units to replace my ailing SMD drives on my PDP-11 systems, I'm confident I'll keep my machines and OSes running for quite some time. I've got two units running now, with only a day's worth of effort primarily due to the unclear documentation, and both are working great with Emulex SC31 UNIBUS controllers (and also with UD33s). If anyone is looking to keep an SMD disk-based system running and concerned about failing media, I highly recommend looking into these used Arraid devices.? The prices have come way down compared to new, and they've been showing up on ebay regularly. Just thought I'd share my success. -scott