MFMulation? (Solid-state replacements for MFM drives)

On 4/15/07, Roger Merchberger <zmerch-cctalk at 30below.com> wrote: Since desktop drives are moving to SATA, compatibility with PATA (and thus easily attached Compact Flash drives) isn't the obvious goal is once was. Yes, there will be large amounts of PATA drives for a number of years, but I can see that in a small number of years, they just won't bother to make them anymore, whereas, Compact Flash is Compact Flash - they may stop making that, too, but they aren't as mechanically fragile, so they may be easier to track down 10+ years in the future. There's an understatement - with a practical maximum number of platters and heads and tracks and sectors with the techniques of the times, no... they never got close to 1GB. They came out at 5MB (ST506) and peaked under 200MB. ESDI was the interface of choice for a short time if you wanted "large" drives on the desktop, then IDE (PATA) swept in and here it is, sweeping back out like the tide. As an aside, I happen to have a pair of 600MB ESDI drives on an SDI controller on my VAX8200, so ESDI isn't just for large PCs, but they were seen there. The Micro Center has house-branded 1GB and 2GB CF cards for a few bucks apiece as impulse buys in bins by the cash registers... right where you'd expect to see gum and candy - if that isn't a sign of how cheap they've become, what is? The real issue, though, one that the OP didn't address directly, is that if you are making a generic MFM drive emulator, you have no way to know how much writing is going to take place, one task that IDE drives have over Flash... If your target host doesn't swap, and doesn't, say, write a magic sector every time you boot, or update access times in the filesystem everytime you read a file, you could probably get away with a Flash drive. If your target machine/OS allows you to boot write-protected media, Flash could be a fine choice. If, however, your OS requires a writeable drive and demands swap space or does lots of filesystems writes outside of human control, Flash might not be a wise choice, cheap or not. -ethan