1 Nov
2009
1 Nov
'09
1:11 p.m.
On Sun, 1 Nov 2009, Fred Cisin wrote:
On Sun, 1 Nov 2009, Tony Duell wrote:
Yes. From what I can tell, power to the head-load and door-lock solenoids
is picked off directly from the +24V input. Looks like the motor PCB is
on the far side of the +12V regulator (uses a "pancake" style direct-drive
motor with a little speed-control board next to it).
Seems to work fine on 24V, which is a relief. This was a brand, spanking
new drive that came sealed in the anti-static bag. With a 1986
manufacturing date, it's the newest such unit in my collection.
Last hurdle is to figure out if I can setup to have the motor run only on
select. There are a few jumpers, but nothing obviously labeled for this
purpose. As it is, the motor starts as soon as the diskette is inserted
and breaks a photo-sensor - doesn't even need the latch closed. I'd be
very surprised if there wasn't a way to change this behavior, but without
documentation it may take some playing around.
Steve
--
It's up to you. I'd problaby trace out
the scheamtics to see just what
was going on. But to be honest, with that 7812, it's going to need more
than 12V, and 24V sounds likely.
Bizarre speculation:
Since most 8" drives use 24V, is there a possibility that this is a 5v&12V
drive design, with the 7812 there to adapt it to 24V?
Is there ANYTHING on the drive connected to that pin of the connector that
does NOT go through the 7812? If not, could you feed it relatively clean
12V downstream from the 7812?