27 Jun
2012
27 Jun
'12
1:45 a.m.
dwight elvey <dkelvey at hotmail.com> wrote:
Hi
If I knew what machine it was intended for, I might
start with a controller like the one in the machine. It
already has much of the needed hardware and then
a simple microcontroller. Not need for high speed.
Say I was making it for an XT. Just find a similar XT
controller. A few interface chips to control the digital
part and the controller to send and recieve the MFM.
A little bit of signal changing but not rocket science.
Dwight
I did something like that for my old eastern Germany Zilog
System 8000 clone (called EAW P8000). There the "WDC controller"
is a Z80 computer accessing the ST506 on one side and
communication with the host via a PIO on the other side.
What I did was now to just take my own solution and attach
it to the PIO and act like the "WDC controller" but with an
SD-Card and optionally an IDE harddisk behind. This was kinda
easy to do as just the PIO communication and the communication
protocol had to be redeveloped.
But - with that way you would need to develop a controller for
every existing computer system in the world where you want to
replace broken ST506 drives. So you have to develop for each
system different solutions and even on some systems those
ontrollers cannot be removed easily and are not attached with
a DB25 cable like mine is where you can just plug another
device onto it.
So - the solution who would more people benefit from would be
of course an ST506-harddisk-replacement solution - but this would
of course also result in much more work to do than just replacing
the controller like I did.
Greetings, Oliver
PS Whoever is interested in what I did... some unfinished
documentation at http://pofo.de/P8000/wdcemu.php and some nice
pictures of my prototype board at
http://pics.pofo.de/gallery3/index.php/P8000/P8000_boards/WDC-Emulator