Dick, I have an Altair that came with a North Star MDS-A disk controller and Shugart SA-400 5.25" disk drives. The disks are hard sectored (10 sectors). I have the manual for the MDS-A card and it does specify the SA-400 drives. There's no mention of using any other drives, either 5.25" or 8". Joe At 09:06 AM 10/28/99 -0600, you wrote:

The N* controller was for 5.25" floppies only - Shugarts and later Tandons were popular. The only board (AFAIK) capable of handling N* hard-sector and 8" soft-sector was made by Morrow and used in their Decision I S-100 box. I bought one after selling my N* and was thrilled to have support for my old N* disks as well as soft-sectored 5.25" floppies. Bob Stek bobstek(a)ix.netcom.com Saver of Lost SOLs -----Original Message----- From: CLASSICCMP-owner(a)u.washington.edu [mailto:CLASSICCMP-owner@u.washington.edu]On Behalf Of Richard Erlacher Sent: Thursday, October 28, 1999 11:07 AM To: Discussion re-collecting of classic computers Subject: NorthStar FDC I got a question the other day, and it was one about which I have no clue. A friend glommed onto an IMSAI box with a North Star disk subsystem, the FDC for which is a model MDS-A4. He wants to know about whether it is capable of handling 8" drives. I didn't think to ask whether it had a 50-pin cable header on it. That would have been too easy. My recollection is that NorthStar systems had a hard-sectored 5-1/4" drive, usually from Micropolis, attached, and that one was pretty dense, but wouldn't do CP/M-standard (IBM-3740 SSSD) diskettes. Is that the case with this controller? Dick