Disc reader project -- quick status update

On 9 Dec 2009 at 11:35, Al Kossow wrote: I've never run into anything that could be classified as "vintage" (>20 years old) that couldn't be handled with the original ISA Mk I board (I do have a MK 3 and a MK 4, but they almost never get used). The clock rates on the CW are somewhat limited, so I haven't done much there. Generally, I aim for the shortest interval between transitions to be about 10-20 clocks, which seems to give adequate results. I wonder if there's anything to be gained by using a sample clock that's a power-of-two multiple of the data rate. It could be argued that dividing an MFM bit cell into 7 sample intervals rather than 8 would lead to a more accurate center-of-cell reading. My current project uses a 14.3MHz clock instead of a 16. I'll know more when I get it running. The saving grace in all of this floppy business is that, unlike hard drives, the push was to make floppies physically smaller, while keeping more-or-less the same capacity. If the same product development had been followed using hard drives, we might be looking at 30MB hard drives the size of the head of a pin... --Chuck