Subject: Re: I need specs ASAP :-(
To: None <CaptnZilog@aol.com>
From: Jim Bender <firstname.lastname@example.org>
Date: 09/30/1998 15:57:35
>>> I think you're confusing the RM03 with the RM05 (which is the 12-platter
>MB drive based on the CDC 9766 I think). <<
>Yup, I guess so... didn't have my handy vax hardware reference book around,
>and its been quite a few years. When I started here we had a room full of
>the CDC removable drives... all gone now.
I have a couple RM03 and RA60 packs I need help getting the data off
of since we no longer have any working drives to read them in. Anyone
out there running anything that can read 'em? :-)
>For reference, I think the RM05/256Mb-CDC drives needed 220/240V at about 14A
>(start current, 10A run) to run them, and the RM02/03/80Mb-CDC (67Mb?) used
>120V @ probably 10A+. Exactly *WHY* anyone would want one these days is
>beyond me... I'd be looking for a SCSI controller, or at least a controller
>for ESDI/MFM/RLL (ST506-interface) drives. SCSI preferred, obviously, since
>even the old ST506 style drives are getting hard to come by. Assuming a
>reasonable rate of perhaps $.08/kwh for your electricity, just to run an
>RM02/03 drive @10A for a 24-hour day would cost you (10A*120V=1200W... being
>generous, say 1kw) 24*$.08=.. about $2/day. For maybe 80Mb... With a SCSI
>controller and an old 80Mb SCSI drive (I have a pile of old Quantum 80's off
>of Mac's that got upgraded) you could probably get the same storage for (being
>overly cautious - 5A@5V=25W, 25W*24h = 600W) roughly $.05/day. 1/40th of the
>I think I'd rather spend $1.50/month on my 80Mb than $60/month, anyday.
I remember when we went from RM0x drives (originally from a pair of 11/70's--
we migrated the drives to a shiney new 11/785) to RA81s that the electrical
consumption decreased dramatically. As did reliability, but that's a
different thread. :-) Going from RA81s to RA9x's was really nice.
>The heat issue comes into play here too, of course... an RM03/05 pumps out
>quite a few BTU's. So, between the power and the heat... just imagine having
>your average 30A/220V circuit Electric Clothes Dryer running 24hrs/7days. And
>probably pumping that much heat into the room its in too!!
I remember a couple of times when the AC quit in the machine room we just
opened the doors and "heated" the building with the equipment. We couldn't
run all of the washing machine drives at the same time tho, or the temperature
would creep up.
>And shutting those RM drives up and down all the time isn't a good idea, since
>that tends to greatly increase your chances for a crash... and those drive
>heads weren't cheap!!
Never noticed this... of course like most shops running that kind of
equipment, we ran it 24/7 and only spun them down when necessary (changing
>Of course, the RM drives are removable... so you could get more packs and
>increase your storage... and from my *wonderful* memories of lifting those
>packs, you could quit your membership at the local gym... might equal that
>:-) Start with an RM03 and work your way up to an RM05...
RM03 packs are nothing. Try lugging RM05 or RP06 packs around. :-)
>Anyways, we now run on four 4Gb SCSI drives rather than a room full of CDC's.
>Power alone we saved over $3000/month. Much less the space we saved (two 6"
>high rack mount chassis for SCSI drives & SCSI tapes, vs. probably 120sq.ft.
>taken up with washing-machine sized hard drives...).
Yea, but not nearly as visually impressive... :-)
>Oh...and those old CDC's transferred at about 1Mb/sec... the new SCSI's do at
>least 5Mb/sec, except that the controller can only do about 3, so we can't
>even get the full bandwith out of the drives. Best our old beast of a machine
The controllers back in the old days (Massbuss, et al) seemed pretty responsive
even if the data flow was slow by today's standards.