There's another option if you're near Manassas VA (roughly DC area):
https://www.ebay.com/itm/VINTAGE-Digital-DEC-RL02-A-Rack-Mount-PDP-11-Disk-Subsystem-Cartridge-Drive/401453950361?hash=item5d78852599:g:480AAOSwuNBZlG8W
Look at the pictures. It's in sad shape but if you look closely it looks
like the heads are locked in place for shipping. He's down to $16.49 (+199
shipping). If you can arrange local pickup it would probably be worth
risking 3 big Macs just for the parts.
Marc
On Tue, Mar 27, 2018 at 6:26 AM, Jay Jaeger via cctech <
cct...@classiccmp.org> wrote:
> My inventory indicates that I have a pair of lower ("UP") heads, part
> number 70-15637 for an RL02. (I don't have any spare "DOWN" heads as
> far as I can tell). I think they might even be new old stock, as they
> are marked "NEW" in my inventory. So maybe we could work something out.
> You might suggest a price, and we can take it from there. Once we get
> agreement, I'll open up the box they are in (in my garage) and confirm
> my inventory.
>
> JRJ
>
>
> On 3/27/2018 4:34 AM, Aaron Jackson via cctech wrote:
> >> On 03/26/2018 04:08 PM, Aaron Jackson via cctalk wrote:
> >>>>> So, from what I can see, the drive should spin up correctly, but for
> >>>>> some reason it goes into fault mode. I am right in thinking that upon
> >>>>> load, the heads should continue moving forward until the first track
> is
> >>>>> found, right? I should not have to perform a seek manually from the
> PDP?
> >>>>> If this is not the case, perhaps there is something else wrong.
> >>>> I’m not an RL02 hardware expert at all, just a daily user back in the
> >>>> day. I’m reading this assuming that at all times the drive is
> >>>> correctly hooked up to an RLV12 in a running PDP with the correct
> >>>> cable and termination present on the drive? If it isn’t you’ll get a
> >>>> fault condition instead of ready after spin up.
> >>>>
> >>>> A
> >>> No worries, your input has been valuable, so thank you.
> >>>
> >>> For anyone else who might have an idea:
> >> ON fault the heads are retracted and will not load till cleared.
> >> Least mine behaves that way.
> >>
> >> Most common problems are wrong drive address, cable issues, no
> terminator.
> >> Others include head lock not removed or the auto unlock style of
> >> headlock has
> >> the tab broken.
> >>
> >>> It seems to be hooked up correctly. When it is in the weird flashing
> >>> ready state, the boot loader says "Read error" or "Device error"
> >>> randomly. The heads oscillate back and forth very slightly as if it is
> >>> trying to align itself better on the first track, which doesn't exist
> >>> because it hasn't moved far enough into the pack.
> >> IF in fault its resetting to retracted on every try.
> >> If not something else is wrong.
> >>
> >>> I'm beginning to think the heads are bad which will be far too
> expensive
> >>> so I may end up giving up.
> >>
> >> Heads are not that expensive... However you could have a wrong pack
> >> or one that has been erased and has no servo tracks. You must start with
> >> a known good pack and cleaned heads.
> >>
> >>
> >> Allison
> >
> > Thanks for the suggestions, Allison.
> >
> > Given that the pack was tested before it was shipped, I am beginning to
> > come to the conclusion that the heads are bad. I can see the servo burst
> > data if I push the heads on a few mm further into pack, but perhaps the
> > heads produce noise which confuse the logic upon load.
> >
> > Heads are more expensive than what I'd like, from what I have seen on
> > eBay.
> >
> > I believe I have a "working" (i.e. non-crashing) down head (as in the
> > one on top). If this is head 0 (anyone know?) then I might have a chance
> > of getting it working without spending anymore money. Let's see.
> >
> > Thanks again,
> > Aaron.
> >
>
