I would add to my previous post that the operation of moving the bumper
holder MUST be done with the disk
at full rotating speed.
In fact, this will move the head, that must fly on the disk surface.
When done with halted disk, the head movement could cause severe damages.
PS - BTW if somebody has a great amount of these disks to be repaired,
I would be glad to have some for my DEC machines here.
Andrea
Clearing out some more of my personal collection
Nice Apple //c plus with original box, Monitor //c with stand and
UniDisk 3.5 drive
$150 dollars Can Deliver to VCFMW/ECCC if paid for in advance
A loaded Mac Plus with 4MB RAM
20SC Hard Drive with 100MB Drive installed
Apple CDSC CD-ROM Unit
PowerUser Syquest 44mb drive with a ton of carts
DaynaPort E/Z Ethernet Adapter for Mac Plus
$150- Can deliver to VCFMW/ECCC if Paid for in advance
Apple //e system
CFFA 3000 Card
Echo II Speech Synthesizer Card
AppleTalk Workstation Card- Lets you connect your //e to AppleTalk Network
DuoDisk 5.25 Drive
Color Monitor //e
Mouse Card with Mouse
Taxan 64k RGB Monitor card, Use any RGB Monitor with the //e
$400 dollars- Can Deliver to VCFMW/ECCC if Paid for in advance
Folks,
I replaced a dead RF74 for a customer this morning and noticed the fault
light was flashing while the drive was spinning up (the 'chirrup noise') so
I set up its DSSI parameters and booted the system.
No errors on startup, and indeed no errors while I was copying things to
it, but the fault light appears to be acting like a drive activity light
which is not something I've ever seen before. The drive works fine, all
$ANALYZE commands are happy.
Anyone?
Cheers,
--
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk
The problem indeed is often caused by a gummy part going to goo after
some years...
The head assembly can move around a fixed axis near a front edge of the
disk.
The extremes of this movement have a couple of bumpers of this
short-lasting gummy,
that after 10 years goes to a viscous black material, loosing its tickness:
that is, the extremes of the movement are now some degree more than the
original device.
Note that the bumpers are attached to metal holders that can be moved
sligtly and that are fixed to
the holding structure with two bolts each. (i can provide pictures of it
all).
The heads when the disk is stopped down "fly" to the park position, that
is on one of the extreme
(the most inner position over the disks).
As the disk is powered up, the electronics put the heads to the inner
end of the parking area,
so the mechanical lock, that holds the heads even when the disk is
powered down, can be easily disengaged.
On the faulty drives, because of the loss of thickness of the bumpers,
this operation let the head to fall
outside the park area (too much toward the inner part of the disk)
causing the electronics to detect a problems,
and so forcing a new park operation, and all restarts....
I fixed this problem on a couple of disks.
I needed to open the disks in a very clean room (few dust around),
powering the disk at open-hearth,
loosing a little the two bolts of the park area extreme, and moving the
bumper holder slowly with the disk in
movement, so letting it retry the spin-up sequence, until it seems to
regain normal operation.
Then I give a little bit more of thickness (we are talking about 0.1mm
more or so) and refixed the two bolts.
Then I tried to power-down and power-up to be sure that all works well.
This saved a couple of disks completely.
If you need it, I can supply good pictures of the inside of the disk,
with some more advice.
Andrea
Hello
I received a email from a movie company wanting to either buy or rent a
IBM model 5150 computer for a moving they are shooting. The museum has
one one but I have no idea what a good rental rate would be per week or
month. Also it would be shipped out of the country and Im thinking a
large deposit would be required for this to happen. Has anyone done
something like this before and can share some tips?
John K
Free for the cost of shipping:
1. NorthStar Horizon Computer System Manual (DD)
2. NorthStar Z80A Processor Board ZPB-A Manual
3. NorthStar System Software Manual4. NorthStar 32K RAM
5. NorthStar Horizon HRAM Users Manual
http://bitpig.com/temp/NS-manuals.jpg
Located in southern California - Orange County 92656
Greetings!
I recently acquired a Heath H89 computer with an H77 disk drive. I've
gotten it to boot into HDOS, but I don't know how to make it do anything.
Is there a reference available online? I mainly want to know how to mount
disks, view their contents and run programs.
Thanks for any help!
Joe
On Sun, 11 Aug 2013 23:55:02 -0600, Eric Smith <spacewar at gmail.com> wrote:
> I still haven't actually seen_Swordfish_. Maybe I'll rent it some day.
>
> Eric
Don't. It is really awful.Travolta and the terrible plot and screenplay
nullify any good which Hugh Jackman, Halle Berry and Vinnie Jones do.
/Jonas
Hi,
A friend of me recently got a nice machine, a ND (Norsk Data)
Satellite Network Gateway.
(For people wondering about Norsk Data, check www.ndwiki.org)
Anyway, the drive in the machine is a Micropolis 1375 scsi drive.
And it stopped working. Of course it was "goo" on the head assembly
bumper(s). He has removed that and inserted a paper strip, but the
drive still doesn't work.
Are there any other known failure modes for the Micropolis 1370-series drives?
Description of symptoms (translated by me, any errors are mine):
- the drive spins up
- disk activity light (on machine?) turns on
- after a while the drive reduces RPM noticeably for about a second
the last two steps repeats, and after about 5 minutes the drive spins
down and stops rotating.
But the disk activity light still blinks, and a faint clicking noise
is heard every time the disk activity light is on.
He also wonders if moving the electronics from a different 1375 drive
to his drive would work, assuming he could get one that works. Has
anyone done this?
(those refurbished Micropolis 1375 drives at about USD 400 looks a bit
suspicious - the technical data is different)
--
Regards,
Torfinn Ingolfsen,
Oslo, Norway