should I take RM03's ?

From: William R. Buckley <>
Date: Fri Apr 5 01:31:47 2002

> Hi all.
> I need some advise.
> In 3 weeks time Edward and I drive to Italy (some 1100 km)
> to pick up several PDP-11/70 parts.
> I have the oppertunity to drag 2 RM03 massbus drives and
> some packs back home. Now I know already that these drives
> weigh about 200 kilo, have a disk capacity of 67 Mb and
> are really power-hungry: at 240 V/50 Hz. stand-by is 3.5 A.
> running they consume 11.5 A. and rush-in current is 22 A.
> My experience is that DEC tend to give high numbers for the
> power consumption, but do these drives eat that much current?
> Are they worth preserving? Or should I leave them where they are?
> Next to the 11/70 is looks great (IMHO) but I would love to hear
> some opinions from other collectors.
> - Henk.

Frankly, do you really intend to use those drives? My point is
that I would acquire them but, only as a component of a complete
system, and definately not as a part which I expected to function.
Compared to contemporary systems, they are woefully inadequate,
and so usage of same seems pointless, if not foolish. Those
drives are museum pieces, and should be viewed as such. Hence,
get them, since they look nice next to the CPU but, do not use
them. Find an alternative source of external storage to use
with the CPU. For instance, I have two RM02's as part of my
11/44 but, I never supply them with power. Instead, for actual
operating storage, I use some Fujitsu Eagles.

As a practical point, I think it is very good to acquire and hold
old mainframes but, it is better to use emulators (like Ersatz-11)
for actual execution. The reason is the excessive power needs of
older systems versus the same for modern systems, not to mention
the tremendous improvement in throughput offered by an emulator
over the old hardware. After all, when it comes to computers,
they are all Turing machine equivalents, yet, no one actually runs
software designed for an actual Turing machine. The results of
execution will be the same, whether executed on a real PDP, or an
exactingly implemented emulator. The only expected difference
will be in the time to completion of program execution.

Sure, sure, I know my position is not going to be well accepted
by those members of our list having a purist bent but, I do
expect that emulators will continue to be effective long after
our hardware possessions stop functioning due to failing parts,

Moral: Forget about using those RM03's. Instead, get them for
the museum value.

William R. Buckley
Received on Fri Apr 05 2002 - 01:31:47 BST

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:34:29 BST