IDE <-> MFM

[Alexandre Souza]

> Head-switching would be a total pig unless you buffered all 8 (or 16) 
> heads at
> once. 8us is not enough to ping an external IDE HDD (or say a CompactFlash 
> or
> SD card) and read off an entire track of data...
> I don't even know how you'd be able to lock a PLL against the write data
> stream quickly enough not to make a hash of it. Most data separators (or 
> at
> least the ones I've looked at) need a few bytes worth of encoded data to 
> lock
> onto before the data window signal is actually valid...
> I suppose you could do what the Catweasel does and save the time between 
> flux
> transitions, but that opens up a whole other can of worms when you want to
> write back to the disc...

    To emulate 10, 20, 30 MEGABYTES? It can be done with a few surplus RAM 
chips or a good PC memory stick! 386's used 32 megabytes of simple DRAM, you 
can get SRAM nowadays for next to nothing in surplus market. There are 2MB 
ram chips from texas, and they are not that expensive. Why not have a SD for 
backup and emulate ALL the drive in RAM? It will be **fast** and, when the 
operation finish, you can press a button (or use some kind of sensing in the 
computer) and backup the entire ram content to the SD card.

    For the used computer market, it would sell like cake. And the cake 
ISN'T a lie :o)

    [],
    Alexandre
    (humming 'still alive')

    (completely offtopic PS: Talkin'bout Portal, have you seen "A day in the 
life of a turret"? No? So have a little laugh: 
http://www.youtube.com/watch?v=Uz5cl131KTk - This is one of the stupidiest 
and funniest thing I've ever saw :D)