13 Jul
2009
13 Jul
'09
8:14 p.m.
Subject: RE: TCP/IP for VMS 5.4
From: "Zane H. Healy" <healyzh at aracnet.com>
Date: Mon, 13 Jul 2009 10:46:51 -0700 (PDT)
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
On Mon, 13 Jul 2009, Robert Jarratt wrote:
If it spins up then back down and repeats thats a stuck head positioner.
When the drive is powered down there is a magnetic retract and at the
end of travel there are bumpers that betwen heat and time get sticky.
The windup then down is the failure of the heads to move and find servo
and it fails.
There are two fixes, temprorary is to freeze the drive and sometimes
they unstick. Me I open the drive, unstick the heads and reach in to
the mech and pull out the goo they stick too. Never had a failure yet
and all 6 of my RD53s are salvaged this way and most were opened over
10 years ago (two approaching 15!) and they are well past their MTBF
now. I haven't opened any in years since I haven't found more and
generally RD53s are more useful to me as spares, swap or for the Qbus
pdp 11s I have. Other than that goo problem they were otherwise
reliable drives.
I also have a boat load of RZ22,23,25, RZ55 and RZ56s in use and a pile of
RD52s (quantumn D540s). The RD52s are only 31mb but perfect for swap or RT-11
based systems as they were very fast for their storage size and unkillable.
I have better than 12 of the D540s as I use them in CP/M based systems as
well.
For backup I use the RZxx as backup as they are faster and more
reliable than TK50. TO create a new system I do a backup/image to
a same size or larger to clone the disk and system. Same for the
MFM drives. Old 1gb SCSI Baracuda drives are excellent for MV3100s
and anything with SCSI and the run forever.
If you going to mess with MFM drives you must have a MicroVAX2000 as its
a good RDxx formatter in a box (RqDX3 compatable). If it has decent amount
of memory and an RD54 in it they can be fun to play with as they are
small and very portable. The alternate is to MOP load VMS to it and use a
small 20-40mb disk for local files and swap. With two you can run LAVC!
Allison
You are right about the RD53s though. The one
that came with the machine
seemed a bit dubious to me but seemed at least to respond in some way (I
could start a boot but it would never complete). Then one day it just went
offline as if it is not attached at all, I wonder if this is not a
mechanical problem but an electronic one in this case? Is there anything
that can be done to revive them?
Most likely you've run into the sticky pads problem. Hopefully Allison
answers this, as I believe she has experience reviving RD53's. IIRC,
basically you open the drive up and remove the sticky rubber pads. I really
don't remember the details as I went SCSI nearly 10 years ago.
Zane
14 Jul
14 Jul
3:29 a.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Allison
Sent: 14 July 2009 04:14
To: cctech at classiccmp.org; cctalk at classiccmp.org
Subject: RE: TCP/IP for VMS 5.4
Allison
Many thanks for the info. I will check the behaviour and then try looking
inside the RD53 when I next have some time. I do in fact have a 2000 now,
that is where my working RD53 came from in fact.
Regards
Rob
Subject: RE: TCP/IP for VMS 5.4
From: "Zane H. Healy" <healyzh at aracnet.com>
Date: Mon, 13 Jul 2009 10:46:51 -0700 (PDT)
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at
classiccmp.org>
On Mon, 13 Jul 2009, Robert Jarratt wrote:
> You are right about the RD53s though. The one that came with the
machine
> seemed a bit dubious to me but seemed at
least to respond in some
way (I
> could start a boot but it would never
complete). Then one day it
just went
> offline as if it is not attached at all, I
wonder if this is not a
> mechanical problem but an electronic one in this case? Is there
anything
that can
be done to revive them?
Most likely you've run into the sticky pads problem. Hopefully answers this, as I believe she has experience
reviving RD53's. IIRC,
basically you open the drive up and remove the sticky rubber pads. I
really
don't remember the details as I went SCSI
nearly 10 years ago.
Zane
If it spins up then back down and repeats thats a stuck head
positioner.
When the drive is powered down there is a magnetic retract and at the
end of travel there are bumpers that betwen heat and time get sticky.
The windup then down is the failure of the heads to move and find servo
and it fails.
There are two fixes, temprorary is to freeze the drive and sometimes
they unstick. Me I open the drive, unstick the heads and reach in to
the mech and pull out the goo they stick too. Never had a failure yet
and all 6 of my RD53s are salvaged this way and most were opened over
10 years ago (two approaching 15!) and they are well past their MTBF
now. I haven't opened any in years since I haven't found more and
generally RD53s are more useful to me as spares, swap or for the Qbus
pdp 11s I have. Other than that goo problem they were otherwise
reliable drives.
I also have a boat load of RZ22,23,25, RZ55 and RZ56s in use and a pile
of
RD52s (quantumn D540s). The RD52s are only 31mb but perfect for swap
or RT-11
based systems as they were very fast for their storage size and
unkillable.
I have better than 12 of the D540s as I use them in CP/M based systems
as
well.
For backup I use the RZxx as backup as they are faster and more
reliable than TK50. TO create a new system I do a backup/image to
a same size or larger to clone the disk and system. Same for the
MFM drives. Old 1gb SCSI Baracuda drives are excellent for MV3100s
and anything with SCSI and the run forever.
If you going to mess with MFM drives you must have a MicroVAX2000 as
its
a good RDxx formatter in a box (RqDX3 compatable). If it has decent
amount
of memory and an RD54 in it they can be fun to play with as they are
small and very portable. The alternate is to MOP load VMS to it and
use a
small 20-40mb disk for local files and swap. With two you can run
LAVC!
Allison
2:58 p.m.
If it spins up then back down and repeats thats a
stuck head
positioner.
When the drive is powered down there is a magnetic retract and at the
end of travel there are bumpers that betwen heat and time get sticky.
The windup then down is the failure of the heads to move and find servo
and it fails.
Just checked, that is exactly what is happening, but it only did cycled two
(or was it three?) times. I will try opening it up to see if it is the
sticky bumpers problem. Has anyone documented the procedure in detail at
all?
Regards
Rob
15 Jul
15 Jul
8:19 a.m.
New subject: VaxStation 2000 as an MFM formatter (was RE: TCP/IP for VMS 5.4)
If you going to mess with MFM drives you must have a MicroVAX2000 as its
a good RDxx formatter in a box (RqDX3 compatable). If it has decent amount
of memory and an RD54 in it they can be fun to play with as they are
small and very portable. The alternate is to MOP load VMS to it and use a
small 20-40mb disk for local files and swap. With two you can run LAVC!
Allison
Wasn't there discussion some time back regarding a difference in
interleave between the VS2000 and an RQDX3 ? Was that ever determined
to be the case ?
-- Curt
9:50 a.m.
New subject: VaxStation 2000 as an MFM formatter (was RE: TCP/IP for VMS 5.4)
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of rescue at hawkmountain.net
Sent: 15 July 2009 16:19
To: General Discussion: On-Topic and Off-Topic Posts
Subject: VaxStation 2000 as an MFM formatter (was RE: TCP/IP for VMS
5.4)
I used a MicroVAX 2000 to format an RD53 just the other day and then put the
RD53 into a MicroVAX II with an M7555 controller and it worked fine. I can't
say whether that worked by accident or by design, but I got the result I
wanted.
Regards
Rob
If you going to mess with MFM drives you must have a MicroVAX2000 as
its
a good RDxx formatter in a box (RqDX3
compatable). If it has decent
amount
of memory and an RD54 in it they can be fun to
play with as they are
small and very portable. The alternate is to MOP load VMS to it and
use a
small 20-40mb disk for local files and swap.
With two you can run
LAVC!
Allison
Wasn't there discussion some time back regarding a difference in
interleave between the VS2000 and an RQDX3 ? Was that ever determined
to be the case ?
-- Curt
17 Jul
17 Jul
12:08 p.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Allison
Sent: 14 July 2009 04:14
To: cctech at classiccmp.org; cctalk at classiccmp.org
Subject: RE: TCP/IP for VMS 5.4
Allison
I have opened up the drive by removing the top plate and I have not found
quite what I expected. The heads are positioned under the platters, I
expected that when retracted they would be to one side of the platters
instead. The platters rotate freely but the heads so indeed seem to be stuck
in that I cannot move the arm (at least not without applying some force), I
am assuming that they are stuck because of the goo you mention. What I am
not sure about is just how to unstick the heads, there does not seem to be
much to get hold of and I am worried that applying too much force may break
something. Once I have the heads unstuck the goo is going to be in-between
the platters, is that right? I cannot see how to get at the goo to clean it
up in that case.
Any advice on what to do? Do I need to remove more parts, or can it be done
just by removing the top plate?
Thanks
Rob
Subject: RE: TCP/IP for VMS 5.4
From: "Zane H. Healy" <healyzh at aracnet.com>
Date: Mon, 13 Jul 2009 10:46:51 -0700 (PDT)
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at
classiccmp.org>
On Mon, 13 Jul 2009, Robert Jarratt wrote:
> You are right about the RD53s though. The one that came with the
machine
> seemed a bit dubious to me but seemed at
least to respond in some
way (I
> could start a boot but it would never
complete). Then one day it
just went
> offline as if it is not attached at all, I
wonder if this is not a
> mechanical problem but an electronic one in this case? Is there
anything
that can
be done to revive them?
Most likely you've run into the sticky pads problem. Hopefully answers this, as I believe she has experience
reviving RD53's. IIRC,
basically you open the drive up and remove the sticky rubber pads. I
really
don't remember the details as I went SCSI
nearly 10 years ago.
Zane
If it spins up then back down and repeats thats a stuck head
positioner.
When the drive is powered down there is a magnetic retract and at the
end of travel there are bumpers that betwen heat and time get sticky.
The windup then down is the failure of the heads to move and find servo
and it fails.
There are two fixes, temprorary is to freeze the drive and sometimes
they unstick. Me I open the drive, unstick the heads and reach in to
the mech and pull out the goo they stick too. Never had a failure yet
and all 6 of my RD53s are salvaged this way and most were opened over
10 years ago (two approaching 15!) and they are well past their MTBF
now. I haven't opened any in years since I haven't found more and
generally RD53s are more useful to me as spares, swap or for the Qbus
pdp 11s I have. Other than that goo problem they were otherwise
reliable drives.
5597
days inactive
5600
days old
5 comments
3 participants
participants (3)
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ajp166＠bellatlantic.net -
rescue＠hawkmountain.net -
robert.jarratt＠ntlworld.com