Micropolis 1015-2 floppy drive

On 15 Jul 2009 at 23:36, M H Stein wrote: I'll check--we used them and their blue-handled predecessors at Durango between ca. 1977-79. I've still got a 1015-II and a 1016-II sitting on the shelf--heavy buggers, with a very slow track-to-track seek. But the way they're built, they'll still be here when the cockroaches rise to replace man. They're basically the same drive, with some very minor mechanical modifications for the drive-insertion microswitch--the PCB is the same. The older 1014? 1012? drives didn't have the "spin the motor during insertion" circuity and they mangled diskette center hubs mercilessly. I didn't see any point in keeping them around so I dumped them some years back. I may have some docs on them, but it'll take a lot of digging. But yeah, single-sided, 100 tpi. ISTR that track-to-track is at least 15 msec. One notable thing is that they have the Micropolis pinout-- e.g. READY on pin 6. I think the 1015's added an edge connector where the earlier ones had only a header for the signal cable connection. ISTR VG used them in a hard-sector application, but we used them as soft-sector GCR (we used a WD1781 as the basis of the controller-- anyone have any of those?) at a somewhat elevated data rate (the drive PCB was slightly tweaked). 12 sectors of 512 bytes per track. I wrote all of the floppy driver code, so I still have a pretty good memory of them. Eventually we replaced them with Tandon TM-100-4M drives; Micropolis was having a miserable time getting the double-sided version of the 1015/1016 to work and there was the seek-time problem, as well as their non-competitive pricing and we ran out of patience. We put our own PCBs and tach circuits on the Tandons--the standard ones didn't cut the mustard. We also briefly used some 100 tpi drives from CDC/MPI that were pretty awful mechanically. I still have the sample 1115 drive that Micropolis dropped off. Still the slow leadscrew positioner, but with buffered seek and a MOS technology processor on board. These were DSDD and could be had in 96 or 100 tpi versions and had a strange mechanical arrangement-- reminds me of an old Fokker airplane engine--when you open the latch on the drive, the positioner assembly, stepper motor, leadscrew and all, swings out of the way. Cast body, not steel plate, like the older drives. A curious drive, but still seeks slowly, even if it is buffered. It was probably a good idea for Micropolis to get out of the floppy business after that. Wonder why I didn't receive Chris' original message? cctech is supposed to be posted to cctalk, is it not? --Chuck