TCP/IP for VMS 5.4

Robert Jarratt robert.jarratt at ntlworld.com
Tue Jul 14 05:29:18 CDT 2009


> -----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
> 
> >
> >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
> 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
> >
> 
> 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
> 
> 
> 

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




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