and the first hp-150 drive set, the hp-9121, was single sided double density SS/DD discs (270Kb). sure was glad when the 9122 came out! Always looking for more HP-150 stuff for our display... any one have a monarch butterfly advertising poster? Ed# _www.smecc.org_ (http://www.smecc.org) In a message dated 10/26/2015 12:52:56 A.M. US Mountain Standard Tim, ccl...@sydex.com writes: On 10/25/2015 11:12 PM, tony duell wrote:
> Not always! The original Sony full-height drives (the 600rm ones) > have a disk-inserted sensor positioned exactly where that hole is. So > if you insert an HD disk the drive doesn't detect it. It is rumoured > this was deliberate (positioning of the HD hole) so that you couldn't > use the wrong disks and have reliability problems. Yes, the Sony OA-D32 drives. Single-sided 600 RPM. One *could* argue, that, given the data rate, it's already "high density" (of a sort). I worked out a BIOS for a Z80 CP/M system called a Preis around 1982, when the drive was pretty new. It was a luggable and had a hard disk option as well. I don't know whatever became of them--but I still have the BIOS listing in my files. I don't think that anyone had any thoughts about putting such a drive in with a controller that would do 1Mbps. Sony never alluded to it in their documentation. The battle of the "pocket floppies", IIRC, hadn't yet been settled in 1982. We could just as well have wound up with the Shugart/Dysan 3.25" floppy--or worse, the Hitachi 3" disks as used in the Amstrad machines. I've still got a couple of 3.5" ED drives, along with blank media--there was a trend that didn't last long... --Chuck