On Fri, Jun 5, 2009 at 4:08 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Indeed.
=A015 years ago, I was able to save the 11/750 from work, but
could not find room for a pair of RK07s and a pickup-truck-load of
I think I'd have takne the drives (and put them on an 11 or something)
and left the VAX. The 11/750 is not a machine I greatly care for....
I've seen your posting about the 11/750 and I cannot refute them given
your interests and proclivities, but this happened to be the machine I
Note that I said that I'd take the drives and leave the VAX. Not that
that that was necessarily the right thing to do, or the thing that you
should have done :-)
Of the VAX 11/7xx machines, the 11/750 is my least favourite, due to the
fact it's stuffed with gate arrays that are, I assume unobtainable now
(and from what I remmeber, when they were avaialble from DEC, they were
ridiculously expensive!) If I had the sapce, I'd love an 11/78x. But I
don't, so I have an 11/730 that I must get round to looking at [1] That
one is 2910s for the data path and rows of unprotected PALs...
[1] I've been spending far too much of my time on HP stuff. Maybe I
should try another manufacturer for a change :-)
first learned VMS on, the first machine I wrote a UNIX
driver on, and
one that' I'd upgraded internally many times (it shipped with 512K and
I upgraded it myself to 8MB to give it five more years of use as the
Ah, that's a darn good reason for wanting to keep it :-). I still have a
soft spot for the machines I fiest wrote device drivers on, for my own
hardware. Namely a TRS-80 Model 3 running LDOS and a CoCo 2 (later a CoCo
3) running OS9.
[...]
RK07 cartridges. =A0Those were good drives - easy to
repair, decent
I am not convinced abotu the 'easy to repair'. I've read the printset,
and that servo system is _complicated_. And don't you need some rather
special tools/test gear to fit new heads?
I don't know about heads - in a decade of running RK07s daily, we
never had to fiddle with heads - we just kept from crashing our packs.
Our failures were all electronics and easy to access, diagnose, and
repair.
Yes, the RK07 electronics is certainly easy to get to. It's quite
complicated, but given the prints, it is not too hard to figure out
what's going on.
I suspect sorting out a subtle prolem in that head positioner servo (there
seem to be 3 feedback loops, from the optical transducer used for
load/unload, from the velocity transducer used when moving, and from
the servo head, used when it's locked to a track) could be an interesting
job, though.
-tony