For the archives, as this might save someone else a lot of messing
around one day :-)
Was struggling to get a 400t to install from tape as it'd always die
with "(open_input_volume) Unable to open volume. (unrecognized error
status 28000B)" after doing a tape retension when loading from the boot
tape.
It was driving me nuts as I'd tested the drive and media elsewhere and
it was fine, plus it was reading CALENDAR / INVOL / DOMAIN_OS from the
boot tape fine. I spent a long time messing around with SCSI cabling,
double and triple checking devices ID's etc.
As a last resort I tried my 150MB SCSI tape drive - I've known it to be
a little flakey with reads sometimes, but I just wanted to see if
behaviour was different. Guess what - it's worked fine!
The 150MB drive is a little newer than my 60MB one. All I can think of
is that the 60MB drive takes a little too long to become ready again
after the retension for the Apollo's liking, and it times out. Maybe
it'd be fine on a slower machine (DN3000 / DN3500 say) but it isn't up
to the job on a 400 series system.
Anyway, maybe this'll save someone a bit of pain one day (it takes
around 15 minutes each to run invol and calendar from tape and well over
30 for domain_os, so it's rather a slow process to keep on having to do!
- I've probably run through it ten times in the last 2 days trying to
figure out what was going on)
cheers
Jules
It's one thing to comment on a specific article, but there's no reason to
indict a whole group of people and say that we're one notch about fast food
workers. That is not only incredibly stupid, it's direct intolerance. He
might as well have been talking about a race or religion or nationality --
which surely would not have been tolerated here.
--- Kurt Huhn <kurt at k-huhn.com> wrote:
>
> Why is it that every time someone says the least thing "boo" about the
> media, you get your panties in a twist? Give it a rest. He's entitled to
> his opinion.
I was playing with an old copy of Acrobat at work and
created a pdf of an old Apple Gift Catalog I had
laying around. Thought I'd let anyone interested know
about it. It was interesting seeing how many items in
it I had picked up at one time or another. You can
find it in my Apple 2 area at
http://www.trailingedge.com/apple2/ in the "History"
section as "Old Apple Gift Catalog".
Side note, are there other options for creating a pdf
like this or is getting my own copy of Acrobat it?
Thanks
There's an AS400 in an auction in Grand Rapids. Current bid, $50.
Auction ends tonight at 8:00 ET.
This is the liquidation of the assest of the company which was busted
by the feds last year for massive investor fraud.
http://www.biddingatauction.com/listings/details/index.cfm?itemnum=795843156
FWIW,
De
>From: "Eric Smith" <eric at brouhaha.com>
>
>Sellam wrote:
>> It would have if it wasn't decided that 80 or so synchronization bytes
>> were absolutely necessary between each sector. I still don't quite
>> understand what reasoning went into that particular aspect of the
>> design.
>
>Suppose you format a disk on a Disk II that is 10% fast. Now you stick
>the disk in a drive that is 10% slow, and write a sector. The 342
>nibbles of the data field will take up the space on the disk that was
>formerly used by 417 nibbles on the disk, or the 342 nibbles of the
>data field plus 75 nibbles of the gap.
>
>And I've ignored the header and trailer bytes, and the new self-sync
>written in the gap and after the end, so it's actually worse than
>that.
>
>As it is, 80 nibbles of gap isn't quite enough to allow for +/-10% speed
>variation and leave still leave enough self-sync bytes, but if they
>reduced it, writing a sector might overwrite the address field of the
>next sector, rendering that sector unreadable (even though the data
>field of that sector would still be intact).
Of course, when did you see a drive that is anywhere
near 10% off in speed? Even the older belt drives could
hold better than +-5%. 5% is over one strobe maker per
second ( for the older disk with stobe marks ).
The newer drives with electronic commutating can hold
much better than that.
Dwight
>
>They couldn't fit 17 sectors without seriously compromising the
>allowable speed tolerance.
>
>Some copy-protected games crammed in more by writing one giant sector
>per track.
>
>Eric
>
>
Some good info and references have already been posted, but another
place to look is "Beneath Apple ProDOS" (the follow-up to "Beneath Apple
DOS"). It covers GCR, nibblizing and the state machine, and includes a
dump of the PROM. It references "Understanding The Apple II", which I do
not have, so I don't know if their content is orthogonal.
Also, I remember hearing that there's some info in the manual that came
with the Disk ][.
-- Adam
I really wanted that too, instead I ended up with
someone very sweet at the time who saw it, knew I
wanted it and went off and made one herself for me.
Still have it and still love it. :)
--- Vintage Computer Festival <vcf at siconic.com> wrote:
> On Wed, 23 Mar 2005 nospam212-cctalk at yahoo.com
> wrote:
>
> > I was playing with an old copy of Acrobat at work
> and
> > created a pdf of an old Apple Gift Catalog I had
> > laying around. Thought I'd let anyone interested
> know
> > about it. It was interesting seeing how many
> items in
> > it I had picked up at one time or another. You
> can
> > find it in my Apple 2 area at
> > http://www.trailingedge.com/apple2/ in the
> "History"
> > section as "Old Apple Gift Catalog".
>
> Oooh, I want the latch-hook rug kit!
>
> Too cool!
>
> --
>
> Sellam Ismail
> Vintage Computer Festival
>
------------------------------------------------------------------------------
> International Man of Intrigue and Danger
> http://www.vintage.org
>
> [ Old computing resources for business ||
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> http://marketplace.vintage.org ]
>
>
>
>
> Message: 3 Date: Wed, 23 Mar 2005 21:11:49 -0500 From: "Ashley Carder"
> <wacarder at usit.net> Subject: RE: TU10 vs TE10 To: "General Discussion:
> On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID:
> <AAECIIBCJNMHBHOFJIBPGEGPCMAA.wacarder at usit.net> Content-Type:
> text/plain; charset="US-ASCII"
>
>>>>>>>> >>>>> "Ashley" == Ashley Carder <wacarder at usit.net> writes:
>>>>>>>
>>>>>>>
>>>
>>> Ashley> What's the difference between a TU10 and a TE10 DEC magtape
>>> Ashley> drive?
>>>
>>> I don't remember a TE10. There's a TE16, which as far as I remember
>>> is a TU16 with the mechanics made more user-friendly (easier tape
>>> loading and all that).
>>>
>>> Looking at the RSTS code, there is no trace of TE10 in there, so it
>>> looks like the difference is invisible to software.
>>>
>>> paul
>>
>>
>
>The tape drive that's currently on ebay with the 11/34 in the short
>cabinet has a label that says TE10 on the back. The seller sent
>me some pictures that appear to say TE10, and he says it's a model
>TE10. Take a look at ebay item 5178288415. Looks like a TU10
>with different style buttons on the control panel.
>
>Ashley
>
The TE10 uses the TE16 transport with a Unibus TM11 interface.
The TU10 used the TU16 transport with the Unibus TM11 interface.
The TE16 is the redesigned version of the TU16 with a better tape path,
auto-rewind to BOT after tape load etc.
The TE10 is the better unit although both are the same spec
800bpi/1600bpi (IIRC) and 45ips (or is it 45ips rewind speed?).
I used to do a lot of Field Service on the DEC tape drives and the TE16
was pretty reliable -- with only the tape locking mechanism
breaking (same part as one of the Kennedy drives).
Bill
Bill
Hi
I meant to jump in earlier when we were talking
about the data formats on disk but got side tracked
with work ( ick! ).
It was mentioned that one could have no more than
two concecutive zeros. It was mentioned that this
was a speed issue of the disk. Actually there is
another reason. The level of the signal from the disk
is constantly changing. Think of driving over a rough
road and you want to count the rocks but not the
larger bumps. If you just set a fixed threshold
on the shocks, every time you went over a bump,
you would miss a bunch of small rocks while the
suspension system was absorbing the larger bump.
Now, if you made the system track the slower larger
stuff, you could ignore the large bump and still
see the rocks. The problem is that the system now
sees the occational rock when there was none for
some time because it is drifting along. By making
sure that there are occational rocks, the system
can stay adjusted to be most sensitive to the
rocks without having false detects.
The disk read is the same, it needs to see data
>from the disk surface to keep the threshold detection
circuit from having false detects from noise and random
level shifts.
Dwight
Is there a "field guide" for HP 9000/300 systems like we have for DEC? I
would like to find more info on, for example, the 98547A RGB video
interface, 7958B Opt 550 disk drive unit, etc.
Also, in my 9000/375 there is a board which fits into a smaller card guide
assy (i.e., it is not the same physical size as the CPU and video modules,
but smaller) which has a paper sticker with several numbers including the
part number: A3057674-11.
It has an 80286 CPU chip on it which leads me to think its some sort of I/O
processor (?). No connector headers on the board; all connections go
through the edge connector. Can't find anything while searching on the
A3057 portion of the p/n (Axxxx is a type of part numbering scheme HP used
for some boards and stuff) nor on many combinations of parts of the p/n.
Thanks for your help.
BTW, while perusing the 'Net through Google looking for DEC SCSI boards I
found an RQZX1 (M5977) for Unibus for 'only' $2999.00 through a reseller
<http://www.varx.com/MODULES.HTML>. A Qbus RQZX1 was pegged at the same
price. Geeez, my wife is hoping to get only $2500 for her used 1993 Jeep
Grand Cherokee with 106k. Maybe they'll take a swap plus a few bucks for
either one? :-)
Regards, Chris F.
NNNN
Christian R. Fandt, Treasurer
Antique Wireless Association, Inc.
Jamestown, New York USA
email: cfandt at netsync.net
Electronic/Electrical Historian
URL: http://www.antiquewireless.org/
