26 Jun
2012
26 Jun
'12
9:48 a.m.
On 6/26/12 9:41 AM, David Brownlee wrote:
On 26 June 2012 14:22, David Riley<fraveydank at
gmail.com> wrote:
You may be able to do something clever on the front end with a propeller. I haven't
looked at what their performance is like. ST412 data rates are on the order of 10Mhz
which isn't going to work with GPIO. Philip is using an FPGA on the Diskferret to
capture MFM data (don't know how much time he's been able to spend on this
lately).
On Jun 26, 2012, at 5:43 AM, David Brownlee
wrote:
I'm assuming the real time computational requirements would preclude
doing something clever with a relatively thin IO board and an
interface into a system running a general purpose OS. On the other
hand given the relative speeds of the interface and a modern CPU maybe
not...
(Envisioning something hanging off a Raspberry pi for a moment :)
Does anyone know of any adaptors to fit a
"modern" drive (be it IDE,
SCSI, ATA, CompactFlash etc) into a machine with an ST-506/412
interface?
That... would be quite the task. The ST-506 and cousins directly
output the raw flux transitions as their data, so you'd need an
emulator which spit out the data as repeated cylinders, I believe.
Trying to interpret incoming data as low-level formatting would be
another matter entirely. You'd probably be better off emulating
the interface to the drives (e.g. emulate an MFM controller).
On the other hand, it's not *that* different from emulating a
floppy drive, which people have done successfully. It wouldn't
be impossible, but I imagine it would take some thought to get
it right.