Hi Gordon
There are a number of possibles but the track 0 sensor
doesn't effect the incremental stepping mechanism used
in these drives. There is no way that it can be off without
being completely off and head over the wrong track.
One full increment of the step is one track.
This is not possible in DOS because it needs to read
the headers correctly to write. It is writing so I'd
guess it is more likely not a full step issue as would be
caused by the track 0 sensor.
Anyway, I suspect that by the sound that the unit makes,
compared to a good one is that the head assembly is somehow
loose or warn. It is not positioning solidly and cross writing
the other tracks.
All this is academic since getting inside this laptop to the
level needed to repair the drive is more than it is worth.
This is the unit with the failing video ( one bus bit missing ).
Once I get the data off it, I may not do anything else
with it. I'm even considering just transferring the hard drive.
That is also major surgery on this laptop ( I know because
I put an oversized [ byte wise ] drive in there myself ).
These things were never intended to be taken apart.
I'm mostly pissed because the stupid format command. The drive
messes up about every third or fourth transfer. In only
about 1/3 of those cases does it trash track 0. I then just
use the magnet. Still, I see little reason why it needs
to see anything on track 0 if it is doing an unconditional
format. You'd think it would just step to track 0 by the
sensor and format it. It would then look to see if it was OK.
Dwight
>From: "Gordon JC Pearce" <gordon(a)gjcp.net>
>
>Dwight K. Elvey wrote:
>
>> Sure but what about not reading track 0 before formatting
>> means it should abort the formatting without first doing
>> a low level format of that track. It is just stupid.
>> If I completely erase the track, it formats just fine.
>> As Sellam says, it is just stupid design.
>> Dwight
>
>I'll bet you'll find that the drive isn't seeking back to track zero
>correctly. All other tracks will be OK but there will be a small
>buildup of shite on the slider knocking the head a tiny bit "inside" the
>proper place for track zero.
>
>What this means is that it partially overwrites track zero, and rewrites
>a new one. But there will be a certain amount of interference between
>the two tracks, and it will not successfully read.
>
>Gordon.
>
>and we dumped the arrogant schmucks
>after 90 days of frustration, wrong billing, stupidity, lost/damaged
>[expensive: $150K] items
Er, Yup... UPS lost a weeks worth of packages on me. About 150 packages
shipped over the course of a week, all via 2 day service... not a one
showed up in their system, and to this day, not a one has been located.
Best guess I can come up with, the driver was picking them up from the
drop box, and just throwing them out all week.
UPS's response... "Oh, well, if we can't find them in the system, then we
can't track them. Are you sure you shipped them?" Upside... at least they
never tried to charge me for the missing packs.
But that is still better then Airborne used to do... overnight packs
would be delayed, I'd call to find out the status, and they would tell me
"it is scheduled for delivery tomorrow" (hmm... define OVERNIGHT). Next
day would come, no package... I'd call again, and be told "no such
package exists in the system" (hmmm... it was there YESTERDAY, when it
should have been HERE!). Following day comes... package shows up, looking
like a mountain lion tried to snack on it.
That was just about every package I got from Airborne Express... which
alas, all the early Mac Catalog dealers insisted on shipping via, so I
was stuck dealing with them far longer then I wanted.
-chris
<http://www.mythtech.net>
Oh my most definitely worth it.
Just a quick report, it's late, it's been a long day, 3 of 4 lanes
closed on return trip adding 2 hr delay, I'll inventory later.
Photos taken (in dark lab at night), will upload tomorrow.
The system was a DOE project measuring the output of a test
cooling tower, some coal burning experiment. The system is
contained in 4 fancy blue DG racks with doors and pretty blue trim
panels. Casters were left on and racks bolted to the floor of a
custom mobile trailer -- double windows, monster A/C system
(Bakersfield summer sun peels paint -- literally). Big analog
input system wired to panel bolted to the wall, cables ran out to
sensors whereeverthehelltheywere. No sun-bleached colors here! No
mouse (eg. meeces, little mammals) presence detected, no birds,
insects, or even humans for 20 years.
Consists of:
Nova 4/X, 6070 disk, two 6120/6123? vacuum column tape drives,
plus a Computer Something Inc 48 channel analog input system (with
full documentation), DG data acquisition system, DG isolated IO
system (cage, cards, docs).
Nova I think is 128K, with mapped RDOS (according to manual notes
and patch tape labels). I dont know nova4 cards by eye, will deal
with later. ALl spotlessly clean. It looks like it was turned off
around 1984/1985 and just left alone.
One brand-new-sealed-in-box cartridge for the 6070. One possibly-
new-but-could-be-bad-in-box cart, plus one in the hole, for three
total.
Dasher RO terminal, dusty but perfect, two cases new sealed
ribbons and a box of greenbar. Too bad no keyboard! Can I add one?
Some big beige modem, with manual.
Custom software full documentation (listings, oper man,
schematics, all mans for the hdwe).
Huge set (may be multiples) of DG manuals, 90% sealed never
opened. 3-ring type (std DG) but no binders (also typical DG).
Appears to include Everything.
Two sets of DG fiche (likely software) one never opened til I
opened it; I found 2nd already opened a few minutes later :-(
WIll get out the reader in a week or two.
About a dozen "system" tapes (backups, dumps, bootable), a couple
of scratch tapes, about 8 DG patch tapes. One tape that must be a
data collect from a program run.
All doors were closed, so there's little dust inside cabinets;
about what you'd see in a system in use for a year or so. THe
trailer was well insulated and sealed, built for field use. No
surface rust of any kind anywhere.
I took even the listings scattered all over the floor
and stepped on heavily. YOu never know.
One minor mistake: the A/D system appeared to be standard telco
wiring at first, so it got dyked out. The wall panel could have
been unscrewed and taken home intact. Not really a big deal, as it
seems likely that the AD thing will be redeployed as such, and it
was just generic wiring, not DG.
THe 6070 was restrained in the rack, and for shipment I had to
remove the disk pack. I wiped off all the dust surrounding first
to minimize contamination. I even found the orig. shipping drive
dustcover! I taped the head opening shut, so the heads wouldn't
zoom out (sorry, but I didn't know what else to do; circumstances
didn't allow determining the right procedure and I've never
shipped or unpacked one) but I put it in the truk so that the head
path was perpendicular to the truck's travel eg. sideways.
Inserted dustcover and clean towel over it, heads still properly
retracted when I got home.
The bad news: the A/C has been off for 20 years! Lots of orangy
dust on the floor and rack externals. It seems more like
disintegrated plastic than clay. Bubble wrap was fully
disintegrated. Who knows what the heat did to the media. We'll
see!
Previous owner was fine; long story he got the trailer with a lot
of other surplus goods, wanted to scrap the computer junk inside,
told it would need to be recycled. A computer-savvy friend of his
told Bruce, etc.
So now my lab is at 120% (physical) capacity, which is actually a
problem. I didn't really intend to packrat another computer (esp.
one so large). But I do like the Nova4, even if it does have a
stack pointer.
The CPU, a tape, disk will certainly fit in two racks; it might
fit in one. I assume systems like this one (random industrial
duty) have no increased value or juice "complete", so paring it
down to managable size might be in order.
I'm not in a hurry -- yet. I will want my lab back at some point!
On Wed I travel to Santa Fe (friend's 50th) (mine soon!) won't have
time to work on it til I get back.
>Use DHL. Their rates are highly competitive with both UPS and Fedex and
>they seem to be saturating the streets with their bright yellow trucks.
>I'm increasingly moving my business over to DHL since they seem to want it
>more.
I'll wait to see how others fair with DHL... they bought Airborne
Express, which was simply THE ABSOLUTE WORST carrier there was... cheap
as hell, but you got exactly what you paid for.
I never had a good experience with Airborne. And after boycotting them
for years, I gave in and let a guy ship me an item Airborne since he
insisted they were the best (even after relaying the many many stories I
had of destroy and/or delayed and/or lost packages)... low and behold,
the box came in ripped to pieces with manuals hanging out the largest of
the holes.
No, thanks, I'll wait on DHL until I know for sure that all the Airborne
people were fired.
-chris
<http://www.mythtech.net>
I have a PCA for an HP 7914 disc drive, part number 07914-60001.
Cosmetically good shape, but I have no 7914 nor will I likely ever. Anyone
want it?
Jay
Hi Guys,
Had a PET 2001-8N arrive a couple of days ago - non-functional
but in otherwise very nice cosmetic condition.
At first I thought it was missing a ROM, as there were only 4
ROMs in the machine, however after looking at them I realized
that it has BASIC 2 installed which is one ROM smaller than
BASIC 4 which is what is in my virtually identical 2001-32N.
Bit of debugging, and I discovered that the problem was ---
yes! - yet another bad PET rom! - fortunately, it was the EDIT
ROM which is the only 2K device, and hence the only device which
can be directly replaced with a more commonly available 2716.
(CS3 which is tied to +5 in the PET lines up with VPP, CS1 lines
up with -OE, and A11 which is always low on accesses to EDIT ROM
lines up with -CE). Programmed a 2716, dropped it in and up it
came!
Now on to UPS ---
I *NEVER* use UPS - not only do they usually break things, but
they charge horrendous brokerage fees to import from the US to
Canada.
Case in point - in spite of my explicitly telling him NOT to send
via UPS - they guy sent it UPS ... Apparently because they agreed
to pack it for him.
To their credit, they did a non-bad job - the PET was wrapped in
about 5 layers of bubble wrap, and then placed in a large box
stuffed with plastic peanuts - much as I dislike PP's, the bubble
wrap protected the machine from getting filled with lots of little
styrofoam bits and seemed to keep it fairly centered in the box.
- the machine arrived in excellent condition, although the cost
for UPS packing and shipping was higher than I had agreed to.
So - it arrives at my door with a bill for an additional $42 ---
thats what UPS charged to provide customs with the declaration that
he had filled out.
... I *NEVER* use UPS!
Regards,
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html
I know we've discussed this before but the right Google search terms are
eluding me.
Is it possible to get 4 floppy drives onto a PC? If so, how? If I stick
two controllers in the PC and configure one with a different base address
and interrupt (assuming I can find a card that allows me to do this) will
DOS automatically recognize the second controller and extend the drive
letters C: and D: to the drives on that card?
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
Hello everybody,
just saved a disk drive with a PDP 11/23 from being trashed.
Unfortunately, someone came before me and took out several parts of this beastie.
The most interesting thing: A Cipher disk drive Model: SF-1221 with a Plessey controller PN: 703340-101J.
A 50pin cable goes to some sort of Plessey converter, another 50pin cable from the converter to the cipher drive.
The drive needs to be cleaned.
On the front panel, a little plate is missing which may have housed some buttons...
Moreover, I found a disk pack which goes with the drive: DEC 2200 BPI-12
Is this a RK03 or RK05 pack ?
Concerning the drive and the controller: Google turned out NOTHING.
Who can give me little help identifying these peripherals ?
Thanks alot !
Pierre
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Hi Eric
I think he means that as long as he stays on that drive,
he has no issues. The write problem is obvious to anyone
that thinks about it a little ( I hope ).
1. A truely blank disk ( bulk erased ) can be formatted
and written on by a 1.2M drive and will work in most
cases on a 360K drive. This may written on by a 360K
drive as well and still work on a 360K.
2. Once a disk has been written on first by a 360K drive
and then a 1.2M, it can only be read on a 1.2M drive!
That's life.
Dwight
>From: "Eric Smith" <eric(a)brouhaha.com>
>
>Doc wrote:
>> I have a 5.25/3.5" combo drive that handles all four of those formats
>> (and 3.5" 360K) just fine. The gorgeous part is that it occupies a
>> single 5.25" bay.
>
>Won't write 360K 5.25" disks reliably. 1.2M drives have a narrower head
>gap than 360K drives, because they use 96 TPI rather than 48 TPI.
>
>Eric
>
>
