> That is because you are writing "320K" disk in a 1.2M drive. > double step is to get 40 tracks instead of 80
Makes sense, thanks. I wasn't 100% sure if this was a 1.2M drive or not. How difficult is it to change a drive? And could it go the other way, upping a 360K stock drive to support 1.2M? I imagine it's not as easy as jumper settings- but a matter of voltage divider maybe? I don't want to void my warranty (joking!! :) ) I think I've heard of people altering their drives, I just hadn't seen it done. I guess another 5.25 related question comes to mind - when a new system was delivered, they had (cardboard?) inserts into the drives. Was that more to protect them during transport/delivery? Or a dust protection? or both? For long term storage (maybe 6+ months?) should we put inserts back into our 5.25 drives? -Steve On Mon, Oct 28, 2024 at 12:30 AM Fred Cisin via cctalk < [email protected]> wrote: > On Mon, 28 Oct 2024, Steve Lewis via cctalk wrote: > > > Thomas, > > Those images for the SHARP PC-5000 boot disk of MS-DOS 2.00 have worked > > splendidly (at least the .IMD files, DiskImage is all I tried). I did > have > > to change the IMD Settings to Sides Two, Double-step On, and the 250kps > to > > 300kps. I don't fully understand that last setting, but absolutely it > was > > necessary - the IMD image file wouldn't write to disk otherwise. > > That is because you are writing "320K" disk in a 1.2M drive. > double step is to get 40 tracks instead of 80 > a 160/180/320/360K drive spins at 300 RPM, and uses 250K data transfer > rate. > But, a 1.2M drive spins at 360 RPM, so you have to either change the drive > to 300 RPM at 250k, OR use the 360RPM at 300K > > (some drives are dual speed; the FDC has a 300bps rate to compensatefor > those that are not.) > > -- > Grumpy Ol' Fred [email protected] >
