AFAIK these are rebadged Japanese (probably NPL) controller and drives compatible with the IBM 3370 series. The 3693-2 is a controller bundled with two drives while the 3690-2 is just two drives, other than skins just like the two in the 3693. They are FBA as opposed to CKD They likely connected to integrated attachments on low end IBM systems and director class control units on the IBM mainframes. I'm pretty sure Memorex never did a 3390 class subsystem Tom -----Original Message----- From: Guy Sotomayor Jr [mailto:ggs at shiresoft.com] Sent: Saturday, December 16, 2017 11:29 AM To: P Gebhardt; General Discussion: On-Topic and Off-Topic Posts Subject: Re: eBay: MEMOREX 3693-2 & 3690-2 Disc Drive Mainframe IBM 3370-2 VINTAGE I *really* want them and I?m within an hour (usually) of where they are. The problem is that right now I?m on a business trip until the end of the month and he needs this gone prior to 12/31. So I can?t get them unless a miracle happens. TTFN - Guy