I'm not sure I've heard of Caldisk, though it was in Anaheim apparently. Maybe a Calcomp brand or spinoff? Here is an ad also for the Matchdisk operation who pasted their info all over the drive. https://books.google.com/books?id=iD4EAAAAMBAJ&pg=PT33&lpg=PT33&… 8" double sided drive, 479 bucks in the 1981 Infoworld ad. CalDisk-142M-17652-111-Pragmatix-I-8-Inch-Internal-Floppy-Disk-Drive-VINTAGE/ http://www.ebay.com/itm/192031318942 Also I'm wondering if the "Matchmakers match of the month" system which they can't tell you about is in fact NoName systems generic CPM system. I never heard of this operation in all the things going on in that time frame (Matchmaker) but they seemed to be marketing to people who were less skilled at fitting things like third party floppy drives to systems, yet this offering is clearly for someone with advanced skills at doing so. thanks Jim