From: Don Maslin <donm(a)cts.com>
Drive select - a choice of 1/2/3 - is determined by
the programmable
shunt at location 1F. Installing a DIP switch is a much handier means
of selection. Configured for multiple drive installation, MX should be
open, HS shorted, and only the desired DSx shorted.
Okay, that's clear.
Termination is by a 150Ohm resistor DIP.
Thanks. There's an empty 14-pin DIP socket adjacent to the above-mentioned
shunt, so I'd guess this is drive is missing the terminator.
The power connector is the same as used on more modern
5.25" floppy
drives with pin-1 at 12VDC, pin-2 12V return, pin-3 5V return, and pin-4
5VDC. Pin one is identified on the component side of the PCB.
Thanks again, this drive does not have a "standard" power connector such as
is found on late-model 5.25" drives -- it only has a four-pin header. Not
being familiar with the SA400, I wasn't sure if this header was normal for
this drive, or if it was some user's modification.
Fred Cisin wrote:
Termination is required on the last drive on the
cable. Lack of proper
termination can make for flaky operation, but will not generally
prevent it from working.
Sure, but I didn't know the details of the terminator since it's missing on
this drive.
I've never seen a factory switch on the front of
one. Are you sure that
that wasn't a user added switch, such as one to override the
write-protect
for flippies?
Not sure at all, but it certainly is professional-looking. Due to my
inexperience, I've never seen an SA400 before and I thought there might
have been variations.
Thanks to both of you for the information.
Glen
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