Joining the list of "my format" posts ...
Mine also records retry information (because MPE on the HP 3000
optionally reports if a retry was done to get a successful tape read),
and setmarks (which differ from EOFs), as well as error information.
(That retry information is important ... it could indicate a silent loss
of information.)
But, I must admit...it didn't occur to me to store metadata like
a photo of the tape, etc. Nice!
When copying / archiving tapes ...
One important thing to do, depending upon your operating system
and tape drive characteristics of course, is to issue read requests
for a few bytes more than you expect ... because with some OSs and
some kinds of drives, if you ask for X bytes and the record has more than X,
you'll quietly get X and the rest will be discarded. (That came up in a
court case where I was an expert witness ... an alleged 'expert' had
copied a 9-track tape (badly) and lost data because the records were larger
than
he expected, and his copying tool didn't have that simple safeguard in it.)
A second thing is to be somewhat aggressive in reading the 'end' of the
tape.
The backup tapes I frequently encounter supposedly end with two EOFs
in a row ... except for a few that happen to have extra data past that
point :)
(Of course, with 9 track tapes, you run the risk of going off the end!)
(Yes, that begs the question...if you're archiving a tar tape ... do you
*want*
the data past the first EOF? (Which could be part of a prior (and longer)
tar,
or something else.)) (And then there are the people who put tar after tar
after tar on the same tape :)
Stan
>> Something I forgot to note was that this instrument (the 4261A) was
>> actually manufactured for HP by Yokogawa, I'm not too sure where the
>> HP part ends and the Yokogawa begins, maybe it was designed by HP and
>> built by Yokogawa, or maybe the whole thing was a contracted design
>> for HP by Yokogawa.
>
>Yokogawa is not on the list of HP acquisitions.
Well, hardly an acquisition if they (partially) owned it from the start.
http://www.hpmuseum.net/divisions.php?did=39
YEW is still around today, my dad has purchased scopes for the lab at work
>from them. YHP is separate from YEW, I guess.
>The y have used Fairchild for their source.
>
>If so, that explains the high rate of failure.
>
>Years ago when at Intel, we disqualified Fairchild
>
>as a source for parts because of the poor testing
>
>and high failure rates.
>
>Dwight
I seem to remember the 7474 that failed was actually a TI part, but
I'm not entirely sure now.
Something I forgot to note was that this instrument (the 4261A) was
actually manufactured for HP by Yokogawa, I'm not too sure where the
HP part ends and the Yokogawa begins, maybe it was designed by HP and
built by Yokogawa, or maybe the whole thing was a contracted design
for HP by Yokogawa.
>On Sunday, July 24th, 2016 at 22:17:24 -0700, Don North wrote:
> >On 7/24/2016 2:37 PM, Paul Koning wrote:
>
>>> >On Jul 24, 2016, at 11:06 AM, william degnan <billdegnan at gmail.com>
>>> wrote:
>>>
>>>> ...
>>>> Attempts to boot from RT11SJ.SYS under V04.00 of RT-11 with 24K
>>>> bytes of memory were successful. Attempts to boot with 16K bytes of
>>>> memory were also successful. An RK05 was used as the disk drive. The
>>>> error message "Insufficient memory" is displayed, but some useful work
>>>> might be done with just 16K bytes of memory. However, you did not
>>>> ask if useful work being done was one of the criteria?
>>>
>> FWIW, I used to run RT11SJ on an 11/20 with 8 kW (16 kB) of memory
>> and RC11 system disk, in college. That fit with no trouble, enough
>> room to run RT BASIC and a reasonably application program.
>>
>> paul
>
> And it still works today:
>
> PDP-11 simulator V4.0-0 Beta git commit id: 4065f47f
> sim> set cpu 11/05 16k
> sim> sho cpu
> CPU 11/05, idle disabled, autoconfiguration enabled
> 16KB
> sim> att rk0 rt11.dsk
> sim> boot rk0
>
> RT-11SJ V02C-02
>
> .
> .R PIP
> */L
>
> DTMNSJ.SYS 46 27-NOV-75
> DTMNFB.SYS 58 27-NOV-75
> DP .SYS 2 27-NOV-75
> RK .SYS 2 27-NOV-75
> RF .SYS 2 27-NOV-75
> TT .SYS 2 27-NOV-75
> LP .SYS 2 27-NOV-75
> BA .SYS 7 27-NOV-75
> SYSMAC.SML 18 27-NOV-75
> SYSMAC.8K 25 27-NOV-75
> BATCH .SAV 25 27-NOV-75
> EDIT .SAV 19 27-NOV-75
> MACRO .SAV 31 27-NOV-75
> ASEMBL.SAV 21 27-NOV-75
> EXPAND.SAV 12 27-NOV-75
> CREF .SAV 5 27-NOV-75
> LINK .SAV 25 27-NOV-75
> PIP .SAV 14 27-NOV-75
> PATCH .SAV 5 27-NOV-75
> ODT .OBJ 9 27-NOV-75
> VTHDLR.OBJ 8 27-NOV-75
> DEMOFG.MAC 5 27-NOV-75
> DEMOBG.MAC 4 27-NOV-75
> KB .MAC 33 27-NOV-75
> LIBR .SAV 15 27-NOV-75
> MONITR.SYS 46 27-NOV-75
> RKMNFB.SYS 58 27-NOV-75
> RFMNSJ.SYS 46 27-NOV-75
> RFMNFB.SYS 58 27-NOV-75
> DPMNSJ.SYS 46 27-NOV-75
> DPMNFB.SYS 58 27-NOV-75
> DXMNSJ.SYS 46 27-NOV-75
> DXMNFB.SYS 58 27-NOV-75
> DT .SYS 2 27-NOV-75
> DX .SYS 2 27-NOV-75
> CR .SYS 3 27-NOV-75
> MT .SYS 6 27-NOV-75
> MM .SYS 6 27-NOV-75
> PR .SYS 2 27-NOV-75
> PP .SYS 2 27-NOV-75
> CT .SYS 5 27-NOV-75
> DS .SYS 2 27-NOV-75
> FILEX .SAV 11 27-NOV-75
> SRCCOM.SAV 11 27-NOV-75
> DUMP .SAV 5 27-NOV-75
> PATCHO.SAV 33 27-NOV-75
> VTMAC .MAC 7 27-NOV-75
> SYSF4 .OBJ 33 27-NOV-75
> BASIC .SAV 36
> BAS8K .SAV 34
> DEMO .BAS 3
> 51 FILES, 1014 BLOCKS
> 3760 FREE BLOCKS
> *
> .
> .R BAS8K
>
> BASIC V01B-02
> *
>
> READY
>
> OLD
> OLD FILE NAME--DEMO
>
> READY
>
> LIST
>
> DEMO BASIC V01B-02
>
> 10 REM BASIC PROGRAM TO GENERATE N TERMS OF A FIBONACCI SERIES,
> 20 REM THE FIRST TWO TERMS OF WHICH ARE SPECIFIED BY THE USER.
> 30 REM
> 40 REM PRINT IDENTIFYING MESSAGE
> 50 PRINT "PROGRAM TO GENERATE A FIBONACCI SERIES"
> 60 REM
> 70 REM GET THE LENGTH AND FIRST TWO TERMS OF THE SERIES
> 80 PRINT "HOW MANY TERMS DO YOU WANT GENERATED";
> 90 INPUT L
> 100 IF L<>0 THEN 130
> 110 REM IF HE REQUESTS 0 TERMS,TERMINATE EXECUTION
> 120 STOP
> 130 PRINT "WHAT IS THE FIRST TERM";
> 140 INPUT T1
> 150 PRINT "WHAT IS THE SECOND TERM";
> 160 INPUT T2
> 170 REM MAKE SURE L IS NOT NEGATIVE OR TOO LARGE
> 180 IF L<3 THEN 200
> 190 IF L<50 THEN 220
> 200 PRINT L;"TERMS DOES NOT REALLY MAKE SENSE."
> 210 GO TO 80
> 220 REM PRINT THE FIRST TWO TERMS OF THE SERIES
> 230 PRINT "THE REQUESTED SERIES IS"
> 240 PRINT T1
> 250 PRINT T2
> 260 L=L-2
> 270 REM CALCULATE NEXT TERM AND PRINT IT
> 280 N=T1+T2
> 290 T1=T2
> 300 T2=N
> 310 PRINT N
> 320 REM DETERMINE IF SERIES IS FINISHED. IF SO,DO NEXT ONE.
> 330 L=L-1
> 340 IF L<=0 THEN 80
> 350 GO TO 280
> 360 END
>
> READY
>
> RUN
>
> DEMO BASIC V01B-02
>
> PROGRAM TO GENERATE A FIBONACCI SERIES
> HOW MANY TERMS DO YOU WANT GENERATED?4
> WHAT IS THE FIRST TERM?12
> WHAT IS THE SECOND TERM?5
> THE REQUESTED SERIES IS
> 12
> 5
> 17
> 22
> HOW MANY TERMS DO YOU WANT GENERATED?0
>
> STOP AT LINE 120
>
> READY
V02C-02 is just one of the versions (out of about 23 versions) that are
available on the CD image at classiccmp which is available for download.
The V02C-02 version of RT-11 on the CD has 58 files with 1212 blocks,
although the date on all of the files is November 20th, 1975 or a week
earlier.
It would be interesting to compare all of the common files to see if
they are
identical. I suspect that they probably are.
What I am curious about are the two files:
ASEMBL.SAV
EXPAND.SAV
Did these two files do anything special?
For historical purposes, it would also be interesting to also preserve
the files:
BASIC.SAV
BAS8K.SAV
DEMO.BAS
that you have along with the F4.SAV (or FORTRA.SAV) which DEC
released in 1975 - probably V2 of FORTRAN IV. The early versions
of FORTRAN IV are available elsewhere for download
Jerome Fine
8i I want one for my panel rebuild project
On Aug 12, 2016 3:49 AM, "Rod Smallwood" <rodsmallwood52 at btinternet.com>
wrote:
Hi Guys
Well my panels made to VCF. I have had some feedback and I
expect more.
Currently I have stock of PDP-8/e (Types A and B) , PDP-8/f and PDP-8/m.
PDP-8/i should be out of manufacturing by now. Next up is PDP-8/L.
-++++++++++++++++++++++++++ Order the above now ++++++++++++++++++
Due to our house remodeling and holidays at the silk screen studio it was
quiet up until this week..
However now things have started up again. I'm about to revisit the PDP-8
bezel project.
The prototype had a few issues but nothing major. I should have a painted
example shortly.
Once the PDP-8/L batch are safely in the stock room it will be time to
start on PDP-11 panels.
+++++++++++++++++++++++ Please register interest in bezels and PDP-11
panels ++++++++++++++++
Rod (Panelman) Smallwood
yep think 31 is right.
have RCA tr-5 quad unit looking for more quad recorders always can
swap some computer stuff!
Anyway the fellow I get the tr-5 from... he alsoscrapped a tr-4 and I
have bies of parts when I can access the parts will check for motors!
ed#
In a message dated 8/11/2016 10:58:56 P.M. Pacific Daylight Time,
cclist at sydex.com writes:
On 08/11/2016 10:07 PM, couryhouse wrote:
>
>
> Chuck we have tape.... we also have one of the 30 something track
> heads at smecc..... I guess won would have to build the motorized
> wingaxas... to pull the tape. ... the electronics can be recreated...
> We figure the head is the hard part..... ha! and a empty take up
> reel! Anyone habe one?Ed www.smecc.org
31 tracks if I read the manual right. The tape itself is a mylar
sandwich, so it should be plenty durable. Reel motors should be no
great deal--maybe you could scavenge them from an old Ampex Quadruplex
VTR...
--Chuck
Yes.. I tried 7 bits.. different parity settings, speeds etc. ?Couldn't quite nail it down. ?In every tutorial online for the 6800 being used with PC terminal, they go 8 N 1.. nobody mentions specifically if you are supposed to use hardware or xo/off or nothing though. ?So that's another thing. ?I'm also confused because some docs mention baud rate settings for the cpu board?
I'm also not sure if bad RAM or bad TTL etc could be contributing to just throwing out random junk too.
Sent from my Samsung device
-------- Original message --------
From: Dave Wade <dave.g4ugm at gmail.com>
Date: 2016-08-04 11:33 PM (GMT-08:00)
To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org>
Subject: RE: SWTPC 6800
"Random Stuff" on serial ports can be a speed, data-bits, or even parity
mis-match.
I assume you have tried tweaking these?
Dave
> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Brad H
> Sent: 05 August 2016 06:58
> To: 'General Discussion: On-Topic and Off-Topic Posts'
> <cctalk at classiccmp.org>
> Subject: RE: SWTPC 6800
>
> I think this 6800 is live but I am being dogged by my inabilities when it
comes
> to cabling.? I'm going to purchase a 'proper' db25 female connector and
the
> molex pins for the MP-S connector and solder it up.? I tried sort of using
> jumper wires to make it go.? When I turn the 6800 on, the PC terminal I'm
> using reacts by producing single or strings of random characters.
> According to the SWTPC 'system checkout' stuff, if I get anything at all
> showing up on the terminal it usually means the 6800 is alive.? Based on
the
> notes written on the MP-S, I'm confident I have the correct baud rate and
bit
> (8) and parity (1) settings, but alas, doesn't seem to work.? When I ran
into
> this sort of thing with MSI 6800 it turned out the baud rate switch on the
> serial card wasn't correct, despite factory labelling.? That might be the
case
> here but not really sure how to sort it.
>
> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Paul
Birkel
> Sent: Thursday, August 4, 2016 12:29 PM
> To: 'General Discussion: On-Topic and Off-Topic Posts'
> <cctalk at classiccmp.org>
> Subject: RE: SWTPC 6800
>
Chuck we have tape.... we also have one of the 30 something track heads at smecc..... I guess ?won would have to build ?the ?motorized ?wingaxas... to pull the tape. ... the electronics can be recreated... ?We figure the head is the hard part..... ha! ?and a empty take up reel! Anyone habe one?Ed www.smecc.org
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------
From: Chuck Guzis <cclist at sydex.com>
Date: 8/11/16 21:21 (GMT-07:00)
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
Subject: Re: Tape imaging
On 08/11/2016 07:36 PM, Al Kossow wrote:
> One of the highest projects I have in the queue is getting one of
> John's M4 9914V drives with 18 track MR heads running in my new lab
> at CHM.
I've always wondered how far someone would go to retrieve data from
media that's really off the beaten path.? Suppose someone found a box of
tapes from an old Honeywell Datamatic mainframe.? Huge reels, 3 inches
wide with heaven knows how many channels...
--Chuck
>I really like my old test gear and yes, it just seems right to be restoring
>vintage computers with vintage instruments. HP scopes, logic analyzers,
>DVMs; function generator; Tek scope, frequency counter; as well as just
>'sundry'. But I did break down and buy a DDS frequency generator to work
>on my VHF/UHF ham gear.
>
>On Sat, Jul 30, 2016 at 6:07 PM, drlegendre . <drlegendre at gmail.com <http://www.classiccmp.org/mailman/listinfo/cctalk>> wrote:
>
>>* In fact, the value of old test gear varies tremendously..
*>>>>* Vacuum tube testers of certain makes & models are near the top
of the food
*>>* chain, with clean, working examples pulling $1500+ (USD) on a very regular
*>>* basis.
*>>>>* There's also a strong following for much 'classic' audio
analysis gear (HD
*>>* meters, ID meters, spectrum analyzers, etc.) some very fine multi-meters
*>>* and anything really hi-end like General Radio, Breull & Kejjr, HP, and so
*>>* forth.
*>>>>* Some very early examples from the 1910s to 30's also pull good
value simply
*>>* for visual appeal. Much of this gear is resplendent with embossed, enameled
*>>* panels, sculpted Bakelite knobs, large meter movements and an overall Art
*>>* Deco styling.
*>>>>* Seen a nice Supreme Diagnometer recently? Or any of the 40s-70s
era English
*>>* made tube testers, like the AVO? Hickok also made a series of bench VTVMs
*>>* with massive chromed meters, designed to be large enough that they can be
*>>* read from many feet away.. those are beautiful for display, and guess what
*>>* - they work great, too!
*>>>>* On Thu, Jul 28, 2016 at 5:24 PM, Dale H. Cook <radiotest at
juno.com <http://www.classiccmp.org/mailman/listinfo/cctalk>> wrote:
*>>>>* > At 03:52 PM 7/28/2016, Electronics Plus wrote:
*>>* >
*>>* > >... does as-is old test and repair equip that won't be particularly
*>>* cheap
*>>* > have interest to you guys?
*>>* >
*>>* > It depends entirely on the make and model of equipment. I always have a
*>>* > laundry list of stuff I am looking for - one of the reasons why I bring
*>>* my
*>>* > tablet to meets.
*>>* >
*>>* > Dale H. Cook, GR / HP Collector, Roanoke/Lynchburg, VA
*>>* > http://plymouthcolony.net/starcity/radios/index.html
<http://plymouthcolony.net/starcity/radios/index.html>
*>>* >
*>>* >
*>>>
>
>
>--
>Ian S. King, MSIS, MSCS, Ph.D. Candidate
>The Information School <http://ischool.uw.edu>
>Dissertation: "Why the Conversation Mattered: Constructing a Sociotechnical
>Narrative Through a Design Lens
>
>Archivist, Voices From the Rwanda Tribunal <http://tribunalvoices.org>
>Value Sensitive Design Research Lab <http://vsdesign.org>
>
>University of Washington
>
>There is an old Vulcan saying: "Only Nixon could go to China."
All this talk of older test equipment reminds me of the HP 4261A LCR
bridge I repaired a while back, last winter I think.
My dad found the 4261A in the garbage years ago, and it seemed to work
fine, until one day he powered it up and the display showed garbage.
He decided to open it up, and noticed some uncovered windowed EPROMs.
Knowing that EPROMs sometimes flip bits in their old age, we decided
that was the first place we would look. We were also able to locate
the full HP service manual in PDF form for the instrument which helped
tremendously. In typical HP fashion, it had full theory of operation,
schematics, state diagrams, etc.
Now, I have an EPROM burner that does your typical JEDEC pinout parts,
27 series and such. The issue is that these were Intel i1702A's from
the early 70's I think. Not only are 1702's a totally different
pinout, but they run on 14V (a +5V, and a -9V rail, with no connected
ground, this is how intel got TTL levels on a MOS chip at the time).
The 4261A has a total of 4 1702's, two of which form a finite state
machine which controls the instrument, while the other two perform
display decoding.
I had to pull out my dad's DeVry Console 80, which has adjustable
positive and negative supplies, and I manually clocked out the data
and compared the contents to a dump I found online. I started with the
state machine EPROMs, and compared the data. I did find a few
discrepancies, but there was too much difference to have been bit rot.
Given the sudden nature of the issue, I would have expected one, at
most a couple bit flips, or something much more drastic (like total
chip failure). Upon reading through the state diagrams in the HP
manual, I noticed that there was a change noted in the state diagram
between certain minor revisions of the 4261A. I looked at what the
changes were, and deduced that my ROMs were in fact correct for the
serial number prefix.
At a dead end with the EPROMs, I decided to see if the state machine
was even running at all. I used a DVM in DC mode, and measured perfect
TTL ones and zeroes on all the state number outputs, which means those
outputs weren't changing: the state machine was stuck. I wrote down
the state it was stuck in and referred to the state diagram. I noticed
something interesting. The state machine in the 4261A is able to
evaluate simple conditions and control flow based on those. The state
path to get to the state that the FSM was stuck on meant the FSM was
always taking one of the conditional paths (always true, or always
false, I don't remember which). At that point, I started looking into
the condition circuitry, tracing out the path, checking IC's as I
worked my way back, until I made it back to 1/2 of a 7474 which had a
set input that was stuck active (low). This pin went to a pullup
resistor, and nothing else in our unit (certain options used this pin,
but not ours). We desoldered the IC, and sure enough, that pin was
shorted to ground internal to the chip. We replaced it with a 74LS74,
and the 4261A has been working great ever since, even with the
original 40 year old 1702's.
Also, on the topic of interesting HP products, and perhaps my personal
favorite so far, is the HP dynamic signal analyzer 35670A. This
instrument can perform all sorts of cool measurements. It can produce
a test signal, and measure two different points in the circuit being
measured. The measurement input channels give you a complex number
phasor of the measured signal, which means you can do all sorts of
cool measurements of networks, especially since you can do complex
number math with the equation support of the instrument. The signal
generator will perform sweeps too, of course. This was very useful
determining whether the speaker crossovers my dad built were working
as intended (actually they weren't, and this instrument helped us
uncover a problem). We also used this to do inductor and capacitor
characterization. There are all sorts of applications this instrument
is good for.
Joe Zatarski
Hey guys,
In Don Lancaster's 'Low cost keyboard and ascii encoder' article (Apr 1974), he mentions in the parts list that the SWTPC keyboard mentioned in the article had foil patterns available, full size, free on request. ?I was wondering if anyone out there had them or knew where they might be found. ?I checked SWTPC and Tinaja but they only have the article. ?I've emailed Don in case he had them but probably doubtful.
Reason I ask is I was rather pleased with how my original TVT reproduction boards turned out, and I have a second CT1024 terminal here in need of a keyboard. ?Rather than rigging something up I thought maybe I could just recreate the PCB. ?I can already make the keycaps and the switches themselves are not beyond my ability either.
Many thanks in advance if anyone has these.
Brad
Sent from my Samsung device
