On Mon, Jun 1, 2015 at 1:09 PM, Robert Armstrong <bob at jfcl.com> wrote:
If you actually get an RC-25 drive working, I'd
love to hear about it. I
have three RC25s (one actually in my 11/725 and two spares) and none of them
work. They were never very reliable drives, even when brand new, and are
possibly the worst drives DEC ever made.
Ain't that the truth. I had a 11/725 with a working RC25 back in the
1990s, and I've semi-recently replaced it with a different 11/725 that
did not come with a removable cartridge so I've not been able to spin
it up to test the internal platter. Hopefully it works, but if it
doesn't, (see below).
Fortunately for an 11/23 or 11/83 there are lots of
alternative drives available.
There are. Unfortunately, for Unibus machines (11/725 especially),
there are not as many alternatives.
One I've seen is to nibble a chunk out of the rim of the cover skin
(to prevent pinching) and run a BC-11-A Unibus ribbon cable out to a
BA-11 and stick any number of controllers in that, such as an
easy-to-find-but-power-hungry UDA50. Also good for adding more
serial, etc. Just put RAM in the CPU box and leave all the
peripherals in the external BA-11. Not supported by DEC, but it works
fine.
I've also heard of people using Emulex and other 3rd-party SMD and
ESDI controllers. Those aren't too expensive. Unibus SCSI, OTOH, is
not common, but a joy if you can find one.
-ethan