Soft Sectoring a RK05

I did concider trying a PLL, after all it is the obviouse solution, however I had the PIC dev kit lying unussed after a cancelled contract and this seemed a good reason to play with it, real application, not just led flashing. Also the last PLL i worked with, years ago now, could not be described as robust, locked to everything BUT the intended pulse. No its not rocket science, trap the index pulse, BTW its not midpoint but about 600uS after the 15sector pulse, time one rotation, divide by 16 and use in counter synked to the index, as Tony pointes out, on the RK05 the platter speed is not going to change quickly and the sector leadin at 100us is probably generous compared to more modern drives. You do have to watch the timing a bit though, as an error in the sector time is cumulative. The programming is in fact almost trivial, though there was still a small sense of achievment when I got the format compleat printout, espeshally as this code was unchanged from the final bench test ( pulse generator and scope) test, no patches, no timing fiddles. When I get the time, im sure most here know that problem, im going to do a TTL version, maybee PLL or maybee not, unless someone else does it first. Meanwiile im cleaning some 12 scotor packs so I can do further testing and do an os8 restore. Dave