Check into Amardeep's approach to using SA-800s with a 16FDC. I have a lot of SA 800's.
 Martin Eberhard's approach to using both PerSci and SA 800, and 850's
NOTE from Martin and Cromemco Yahoo Group:
I document how to have a Shugart SA850 drive coexisting with a Persci 277 (or 299) on the same 16FDC. Works great, and allows me to read and write pretty much any type of disk, including disk reconstructions from .IMD files.
I also include a table that compares the interface pinouts, as well as tables that show jumper settings for Persci 277s, Shugart SA800s and Shugart SA850s. NOTE: The 850 and 851 are actually the same hardware - there's a pair of jumpers on the board that are labeled "850" and "851". The 851 option sets the drive up for hard-sectored disks.
CDOS2.53 fully supports the Persci voice-coil drives, with super-fast seeks (as well as supporting Shugart drives). CDOS 2.58 does not. I suspect (from your quote of the Cromemco release note) that they broke Persci support with version 2.54 - so 2.53 should be okay. I read someplace or other that the 2.54 release was intended to support some other drive (Tandon?), which I don't care about.
If you (or anybody else) have CDOS 2.58, try running CDOSGEN, and see if it gives you the "V" option for seek speed on Large drives. If so, I would love a copy of that CDOSGEN..