That is an MSD SD-2 dual drive. It was sold as a premium drive for the Commodore 64, and supports either serial or IEEE-488 interfaces. It would work with a PET, as well, via the IEEE-488 interface. One of its compelling features is its ability to copy a diskette completely in its firmware with one command, and quickly. If you would like to sell it, I would be interested :>. Nice find! --Michael Passer mwp(a)acm.org -----Original Message----- From: CLASSICCMP-owner(a)u.washington.edu [mailto:CLASSICCMP-owner@u.washington.edu]On Behalf Of Charles E. Fox Sent: Wednesday, August 25, 1999 8:12 AM To: Discussion re-collecting of classic computers Subject: Strange drive unit I found this in one of my cupboards, don't know where or when I got it. Micro-systems development Inc. Dallas Texas Model SD-2 Two TEC 51/4 floppy drives, Model FB501, mounted vertically Built in AC supply Rear panel has two 6 contact female DIN sockets and one 24 contact female connection similar to a Centronics printer, only smaller. The construction is generally similar to that used on Apple ][ drive cases, although I suspect this might have something to do with a PET. Can any one enlighten me? Regards Charlie Fox Charles E. Fox Chas E. Fox Video Productions 793 Argyle Rd. Windsor N8Y 3J8 Ont. Canada email foxvideo(a)wincom.net Homepage http://www.wincom.net/foxvideo