18 Jan
2011
18 Jan
'11
6:40 p.m.
On 01/18/2011 07:13 AM, Jules Richardson wrote:
Was it really done that way because it was supposed to
look just like a
big floppy at the interface level? Is that actually documented
somewhere?
Yes, the manuals for the SA4000 and SA1000 series specifically state
that the control interface is intended to be similar to that of a floppy
drive. Even had they not stated that, it is completely obvious looking
at the signal descriptions.
What would be needed to add a parallel address
interface? A counter,
comparator, maybe a latch for the address? Anyone care to estimate
parts cost to have done it that way at period prices vs. what an actual
drive cost? I suspect it wouldn't have added a significant amount to the
cost, which does perhaps suggest that it was done the way it was on
purpose.
Of course it was done that way on purpose. Why have counters on each
drive, when you can put them on the controller instead?
It's not like these things had voice coil actuators. The seek was going
to be slow regardless of where the counters were.
Eric