HDTenEightyP/NetNews huggingface dataset:
From: printf@cix.compulink.co.uk (Ian Stirling)
Newsgroups: sci.electronics
Subject: sa
Date: 6 Apr 92 17:43:34 GMT
Reply-To: Ian Stirling <printf@cix.compulink.co.uk>
Organization: Gated to News by demon.co.uk

I have a quantity of modem type cables for sale.
These are good quality 25 pin male D to 25 pin female D, connected by
three to four metres of ribbon cable.
For sale for 5UKP(British Pounds) including P&P(only within UK),
excluding vat.
For every three you buy you get one free.
Mail me if interested.
Is there a more suitable newsgroup than this?
Printf.
Printf@cix.compulink.co.uk
(Ian Stirling.)
Newsgroups: sci.electronics
From: fculpepp@norfolk.vak12ed.edu (Fred W. Culpepper)
Subject: Re: Before camcorders - info wanted
Organization: Virginia's Public Education Network
Date: Wed, 15 Apr 92 02:39:16 GMT

bryanh@hplsla.hp.com  writes:
> 
>      Before camcorders, there were video cameras.  A bit smaller than
>   today's VHS camcorders, these things were plugged into certain VCRs
>   that had the appropriate adapter (a DIN-like connector with 5 or 10
>   pins).  The VCR was either stationary or portable; the portable had
>   a shoulder strap and batteries.
> 
>      An acquaintance picked up several of these beasts, minus the
>   VCR portion, and has asked me for assistance.  Does anyone know
>   anything about these video cameras?  

I used a Sylvania video camera in 1960 which was connected to a
monitor and drew its power from the power supply in the
monitor.  While this is ancient history, maybe I can shed some
light on your questions.
> 
>      Specifically:
> 
>    - The connector appears to be standard between vendors.  Is (was) it?
> 
>    - Can the camera be made functional without the VCR?  In other words,
>      can I put in power and get out video?  Or was some important part
>      of the electronics in the VCR portion (scanning circuits, etc)?
> 
In the camera I speak of, the scanning signal was supplied from
the monitor (made the sync problems simple) and as I recall,
the monitor also supplied the power, however I might be
mistaken in this point.


>    - Any ideas where I could get documention on the connector?
> 
>    - Finally, how does the picture quality in these old cameras (vidicon
>      tubes?) compare with the new CCD technology?  
> 

The vidicon had a "memory" which means that when you panned the
camera the resultant picture on the monitor was smeared until
the camera was at complete rest.  Usually it took about a
second for the memory to fade and the image on the monitor to
resume it detail.  As for quality, the vidicon is old technology
and at its time was a marvel because it was a TELEVISION
CAMERA!!!!  If you have ever seen pictures of kinescope
recordings of boxing matches, the ropes appear to pass right
through the boxer's bodies.  This was typical of the vidicon
image tube, the smear and "memory" were facts we lived with at
the time - we didn't know they could be corrected.  Neal
Armstrong's first steps on the moon were recorded using a
videcon image tube.  Look closely the next time this is shown
on TV and you will get a good idea of what a vidicon would do.

One of the common problems with the vidicon was the adjustment
of the brightness and contrast controls.  Unless they were set
correctly (very critical) the picture would tear apart when the
light level would change drastically.

-- 
Fred W. Culpepper, ODU

fculpepp@norfolk.vak12ed.edu
From: Jeff.Lindstrom@ofa123.fidonet.org (Jeff Lindstrom)
Newsgroups: sci.electronics
Subject: Source for miniature cable wanted
Date: Thu, 09 Apr 92 01:07:10 PDT
Organization: Universal Electronics Inc. (Public access BBS)

  You can call Digi-Key at 1-800-344-4539 (FAX # 1-218-681-3380) and ask for a catalog.  They have 4 pages of multiconductor cable in their current catalog.



--  

Jeff Lindstrom
Internet: Jeff.Lindstrom@ofa123.fidonet.org
Compuserve: >internet:Jeff.Lindstrom@ofa123.fidonet.org
From: jimc@isc-br.ISC-BR.COM (Jim Cathey)
Newsgroups: sci.electronics
Subject: Re: MC68000
Date: 8 Apr 92 23:54:39 GMT
Organization: ISC-Bunker Ramo, An Olivetti Company

In article <1992Apr6.033214.15677@resmel.bhp.com.au> jing@resmel.bhp.com.au (Jian Feng) writes:
>>  - On powerup or hard reset, the bottom of the address space should be ROM,
>>    but later on you need at least a few bytes of RAM there. This requires
>>    some switching of address ranges by control signals to the address
>>    recognizer.
>
>Easy. MC68000 reads in the Stack Pointer (SP, the system stack pointer)
>and the Program Counter (PC) from address $0. It takes 4 read cycles on
>the 16b bus. Just use a simple 2 bit binary counter which is reset on
>power-up and on counter-overflow it can switch the address.

However, it is better to use an I/O port bit to control the ROM overlay
because then you can have exception vectors in ROM as well.  This allows
your system to be bulletproof while it is doing the initial RAM diagnostic.
After RAM is certified OK, you can copy the vector table to the RAM image
of the vector table, then throw the bit to turn off the ROM overlay.  Our
systems all work this way, as does the (early, at least) Macintosh.

>>If you want something tricky like zero-wait-state DRAM, then of course it's
>>a nightmare. (How's that implemented, anyway? Does it require software
>>supervision to handle the refresh? I normally use a store-bought DRAM
>>controller chip.)

The 68000 is not very efficient in its bus timing.  It is easy to hide a
memory refresh cycle in the first half of the memory access cycle.  In
fact, a number of 68000 systems (including ours, the toaster Macs, Ataris
and Amigas) run the memory at double-speed and put a video cycle in the
first slot.  As a bonus, video is free (no access time penalty) and refresh
is free (courtesy of the video).  A 7 MHz 68000/68010 only needs 150 nsec
DRAMS in order to do this trick.

Of course, newer members of the 68K family are faster, and won't let you
get away with such 'cute' timing.  C'est la vie.

+----------------+
! II      CCCCCC !  Jim Cathey
! II  SSSSCC     !  ISC-Bunker Ramo
! II      CC     !  TAF-C8;  Spokane, WA  99220
! IISSSS  CC     !  UUCP: uunet!isc-br!jimc (jimc@isc-br.isc-br.com)
! II      CCCCCC !  (509) 927-5757
+----------------+
			"PC's --- the junk bonds of the computer industry"
Newsgroups: sci.electronics
From: adm@ccadfa.cc.adfa.oz.au (Alan Moss)
Subject: Re: parity-error!
Organization: Australian Defence Force Academy, Canberra, Australia
Date: Tue, 14 Apr 1992 01:01:00 GMT

I have seen this message on 2 occassions.
On the first I was trying to install 2 LAN cards in a 286 based PC
and everything was ok until I installed the second card. It worked ok 
with either card but not with both !

The second was due to a bad SIMM in a 386 based PC.
Replaced the SIMM.. problem fixed.

Watch out for interaction between add-on devices which share memory
with the PC. Remove these items one at a time until the message goes away.
From: myers@hpfcso.FC.HP.COM (Bob Myers)
Newsgroups: sci.electronics
Subject: Re: Pre- & De-Emphasis
Date: 14 Apr 92 19:05:50 GMT
Organization: Hewlett-Packard, Fort Collins, CO, USA

>>  Would someone (Bill?)  mind giving an explanation of deemphasis, how it is
>>done, the reason for doing it, what is done the the signal, etc.?  Thanks.
>   Your explanation left out the reason why pre- and de-emphasis is necessary

>   The Bass signals are often too strong and would overload recording media, 
>so the signal strength is reduced (SNR is not a major consideration in this 
>frequency range).  During playback, the Bass frequencies are boosted to 
>restore their balance with the Midrange and Treble.

Not quite; while this is the correct explanation for RECORDING pre-emphasis,
remember that the original question was in the context of FM broadcast signals.
In FM, preemphasis is necessary to maintain a reasonably consistent SNR across
the frequency range of the original modulating signal; due to some of the
mathematical complexities of the FM process, the SNR will be lower for the
high-frequency components of the original signal IF the deviation is the same
across the frequency range in question.  Boosting the high end prior to 
modulation compensates for this by causing greater deviation for the high-end
signals, relative to the bass end.  Of course, it has to be UN-done at the
receiving end (to restore the proper tonal balance), and so the need for
DEemphasis at the receiver.  This process would NOT be necessary if phase
modulation is used, but PM has other problems which make it less suitable for
broadcast (music) applications.

(Further understanding of why the SNR varies with orig. freq. as mentioned
above requires some understanding of the spectrum resulting from the FM
process; consult a good communications text for details.)


Bob Myers  KC0EW   Hewlett-Packard Co.      |Opinions expressed here are not
                   User Interface Tech. Div.|those of my employer or any other
myers@fc.hp.com    Fort Collins, Colorado   |sentient life-form on this planet.
From: sakari@laureline.cs.hut.fi (Sakari Aaltonen)
Newsgroups: sci.electronics
Subject: Re: Taking the Lid off Plastic DIPs
Summary: SUMMARY POSTED IN sci.chem: look for Dissolving Epoxy
Date: 7 Apr 92 07:29:52 GMT
Reply-To: sakari@niksula.hut.fi (Sakari Aaltonen)
Organization: Helsinki University of Technology, Finland


--
-----------------------------------------------------------------------------
Sakari Aaltonen                             Helsinki University of Technology
Email: sakari@cs.hut.fi
---  You can't keep a Finn down without him getting all red in the face  ----
Newsgroups: sci.electronics
From: pschauer@den.mmc.com (Paul Schauer)
Subject: Signetic's SLICE PAL software
Summary: Problems w/ SLICE
Originator: pschauer@evans
Keywords: SIGNETICS, SLICE
Organization: Martin Marietta Astronautics, Denver
Distribution: na
Date: Wed, 8 Apr 1992 20:11:40 GMT

Sorry about the last posting. Take II:
Has anyone out there used Signetic's SLICE software? I will not post the 
problem I have with the software on the net, but I would like Email from
anyone who might have used the program. I know there are better programs
out there, and I have a call into Signetics, but experience does count...
Thanks in advance, 
Paul Schauer
From: phil@yogi.axion.bt.co.uk (Phil DNM44)
Newsgroups: sci.electronics
Subject: Re: Color monitor problems; got a magnet near it by accident.
Date: 13 Apr 92 15:02:12 GMT
Reply-To: phil@yogi.axion.bt.co.uk (Phil DNM44)
Organization: British Telecom Research Labs


switching the monitor on and off a few times should mend it.
-- 
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
phil houseago                   |When you hang up that phone,   
phil@muppet.bt.co.uk            |You cease to exist ...
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
From: dino@inqmind.bison.mb.ca (Tony stewart)
Newsgroups: sci.electronics
Subject: Re: Hex-FET's and infinite impedance
Date: 10 Apr 92 21:54:52 GMT
Organization: The Inquiring Mind  1 204 488-1607

adams@pdv2.fmr.maschinenbau.th-darmstadt.de (Adams) writes:

> In article <4764@umriscc.isc.umr.edu> dshipley@cs.umr.edu (Dan Shipley) write
> 
> >   I just got a car audio amplifier from Coustic.  In the manual, it says it
> >   uses hex-FET's and NOT to turn the amplifier on if there is no load on th
> >   outputs.
> 
> >   I don't know anything about hex-FET's, but it seems unusual that an infin
> >   output impedance would cause damage to a transistor.  However, I'm always
> >   learning just how much I don't know, so if someone could enlighten me in 
> >   ways of hex-FET's or why this might cause damage, I'd be grateful.
> 
> first guess (using hexfets as a linear voltage controlled current source):
> How about oscillating? It is not so uncommon, that amplifiers may not 
> be operated without specified burden. It is not uncommon, that 
> infinite impedance (e.q. no burden) fries an output stage. Ask an RF engineer
> 
> second guess (hexfets used as current switches): As you can use it as a
> voltage controlled current source, and switch it very easily, you can use
> it as driver stage in a a low resolution (down to 1bit) D/A converter.
> To obtain your signal, you need a reconstruction filter. This may be 
> the impedance of your speaker set / earphone. As much as I know, some
> walkmans by Sony use this strategy.
> 
> Just guesses... adams.
> 
> If I am wrong, please tell me so --- but no flames.

It may be that the audio circuit is unstable in this mode.
Most Audio amps have a tnedancy to oscillate (100KHZ typ) unless there is 
a HF load try using a RC load that applies say 8 ohms above 
|>LnI(XXw*e~
tG[myow3
20KHz..choose the appropriate series cap.

dino@inqmind.bison.mb.ca
The Inquiring Mind BBS, Winnipeg, Manitoba  204 488-1607
From: mcovingt@athena.cs.uga.edu (Michael A. Covington)
Newsgroups: sci.electronics
Subject: Re: radar traps
Date: 12 Apr 92 03:46:25 GMT
Organization: University of Georgia, Athens

I was on the jury for a radar speeding case which the judge threw out
because the county did not bring in its FCC license for the radar.

They had the license but had gotten sloppy about bringing it into
court when the law required them to do so.

Judges tend to be prejudiced in favor of one thing: Making The System
Work.  That means making everybody on both sides play by all the rules
and not waste time.  And this often works in the defendant's favor.

-- 
==========================================================================
Michael A. Covington, Ph.D. |  mcovingt@uga.cc.uga.edu  |  ham radio N4TMI
Artificial Intelligence Programs | U of Georgia | Athens, GA 30602  U.S.A.
==========================================================================
From: kolstad@cae.wisc.edu (Joel Kolstad)
Newsgroups: sci.electronics
Subject: Re: DC Shock
Date: 12 Apr 92 04:32:14 GMT
Article-I.D.: doug.1992Apr11.233214.1969
Organization: College of Engineering, Univ. of Wisconsin-Madison

In article <1992Apr11.195125.9468@ux1.cso.uiuc.edu> berger@atropa (Mike Berger) writes:
>>jon@sparcplug.et.iupui.EDU (Jon Burgoyne) writes:
>
>>> I'm looking for a small circuit that could provide a shock to my dog.  This i
>>> to build a collar similiar to the invisible fence product.  I believe they us
>>> a 22.5v bat.
>>> 
>*----
>Why does anybody want to help this guy torture his dog?
>--
>	Mike Berger

Oh, please.

Shock, in the sense Jon means, is NOT torture.  It's simple the slightly
undesirable sensation of current running through the skin.  Go put a nine
volt battery on your tongue.  You probably won't like it, but it's far
from torture.

If dogs were smart enough that you could tell them not to wander outside
their yards, fine -- maybe we wouldn't need shock collars.  But they can't,
and the only thing that a dog is going to understand when its master isn't
standing right over it is some remote physical stimulation -- high frequency
sound, shocks, or whatever.

If you want to talk about taking this idea a little too far, perhaps we should
discuss cattle prods.  I've been told that these things are quite painful to
the beast of which they're applied...

Finally, if you meant this humorously, you can disregard the above.  But
I didn't see a smiley...

						---Joel Kolstad
						kolstad@cae.wisc.edu
From: smckinty@sunicnc.France.Sun.COM (Steve McKinty - Sun ICNC)
Newsgroups: sci.electronics
Subject: Re: Paranoid about my hz?
Date: 17 Apr 92 17:35:22 GMT
Organization: Sun Technologies Enterprise Inc.
NNTP-Posting-Host: hardy.france.sun.com

In article <1992Apr17.155329.11589@mav.com>, toddi@mav.com (Todd Inch) writes:

   > >> This is a simple question for any of you. If I want to use an over the
   > >> counter step down transformer so that I can use my printer in Germany,
   > >> do I need to be concerned about the difference in hz?
   > >> 
   > >> I have been told that what goes in comes out, so I will be feeding
   > >> the printer 110 at 50 hz, and the printer specs say the source should
   > >> be 110, 60hz plus/minus 3hz. 
   > 
 
   > I did read somewhere, probably in a Toshiba printer owner's manual,
   > that while there product usually did work on 50 Hz, it was not
   > guaranteed or recommended, that it would likely shorten the printer
   > life (something ran a little hotter than intended, I believe) and would
   > void the warrantee.

I think the eddy current losses in a transformer will increase if you run it
outside the design frequency, and so it will warm up a bit more. If
the printer power supply normally runs cool, I think you'll be OK. If
it usually runs warm or hot to the touch, it might not be a good idea.
I doubt if anything except the transformer will be bothered.

   > 
   > If you will be frequently going back and forth between north america
   > and europe, I'd recommend finding a printer which is 110/220 V
   > switchable and also rated 50/60 Hz, which shouldn't be all that
   > difficult.  Recently, I've even seen some computing equipment that
   > AUTOMATICALLY switches between 110 and 220, or possibly it doesn't
   > really "switch" at all but just has a very tolerant power supply input
   > range.

Many modern workstations have switchmode power supplies in them, and can cope
with anything between 100 and 240 volts, the power supply is just designed
to be very flexible. 

Steve
-- 
Steve McKinty
SUN Microsystems ICNC
38240 Meylan, France
email: smckinty@france.sun.com	   BIX: smckinty
Newsgroups: sci.electronics
Subject: HELP needed with colour LCD displays
From: geoffrey@cosc.canterbury.ac.nz (Geoff Thomas)
Date: 8 Apr 92 14:27:24 +1200
Distribution: world
Organization: Computer Science,University of Canterbury,New Zealand


Hi, I've got a couple of colour LCD displays (from some
cheap SEGA Game Gears) and I want to use them on their
own. They seem to be multiplexed in some way (3 sets of
18 wires on the bottom of the display, and 6 or 7 wires
on the side), with digital signals going in to these.

The displays are somewhere in the order of 160w X 100h
pixels, and can display at least 32 colours, (that may
be the Game Gear's fault, and not the limit of the display).

Any help on how to drive these panels would be much
appreciated.

Thanks in advance,


Geoff Thomas.

Newsgroups: sci.electronics
From: richtt@aix.rpi.edu (Timothy G. Richter)
Subject: Waking up IBX box
Organization: Rensselaer Polytechnic Institute, Troy NY
Distribution: na
Date: Sat, 11 Apr 1992 05:00:39 GMT


Here at RPI, we have a digital interface from PCs to the mainframes.  They are
IBX "boxes" and I need to "wake it up" from software.  The IBX is made by
InteComm, and I think one of the serial port lines is turned on to wake
up the communications.  Could someone tell me which line(s) to turn on and
how these lines can be turned on through software.  A quick assembly routine
would be ideal.

-Tim Richter
richtt@rpi.edu

Newsgroups: sci.electronics
From: jvp@juliet.ll.mit.edu ( Jim Pieronek )
Subject: Re: Front panel finish - related question
Organization: M.I.T. Lincoln Lab - Group 43
	<167C59A26.STATRAA@YaleVM.YCC.Yale.Edu>
Date: 10 Apr 92 11:35:03

In article <167C59A26.STATRAA@YaleVM.YCC.Yale.Edu>
STATRAA@YaleVM.YCC.Yale.Edu writes:

   I have a related question dealing with front panels - I have a steel
   chassis that has a black anodized aluminum faceplace that fits over the
   steel front plate, with a spacing between the two of about 1/4" -- this
   allows a professional looking product becuase it allows swithces and
   whatnot to be mounted on the rear (front) panel, and keeps unsightly
   nuts, washers, and tightening scratches off of the front panel.  My
   problem is this -- on many pro units they use this same scheme, and cut
   small OVAL holes in the faceplate to accomodate the toggle switches -
   this looks great, and I'd like to do something similar - but HOW can I
   cut OVAL holes???

   --
     ==================================================
     [   Travis Stansbury, Yale University - ES '94   ]
     [   statraa@yalevm.ycc.yale.edu                  ]
     ==================================================

                            ^^^^^^^^^^^^^^^^^^^^^^^

Being a University student in engineering, you or your ME pals should
have access to a half-decent milling machine.  These marvels of modern
technology allow you to clamp your work piece into an x-y table that
you can move with great precision underneath a stationary rotating
cutting bit, i.e. a drill.  Have fun, but practice on some junk first.

There are also punches available for this task, but they cost an arm
and a leg ($25 is an arm and a leg as far as this job is concerned,
right?) and will probably not come in exactly the size you want.

We use our milling machine to cut long skinny slots in VME front
panels to accomodate 50-pin connectors.  Works just dandy.

- Jim
--
J.V. Pieronek                           Internet: jvp@ll.mit.edu
Massachusetts Institute of Technology   (617) 981-3468
Lincoln Laboratory                      These are my opinions, not the Lab's.
From: pjh@mccc.edu (P. J. Holsberg)
Newsgroups: sci.electronics
Subject: Sun Monitor Interface
Date: 13 Apr 92 16:19:54 GMT
Organization: The College on the Other Side of U. S. 1

Has anyone cobbled up an interface between a Sun monochrome monitor and
a PC-type EGA/VGA/SVGA/??? board?

Thanks,
Pete
-- 
Prof. Peter J. Holsberg      Mercer County Community College
Voice: 609-586-4800          Engineering Technology, Computers and Math
FAX: 609-586-6944            1200 Old Trenton Road, Trenton, NJ 08690
Internet: pjh@mccc.edu       Trenton Computer Festival: April 11-12, 1992
Newsgroups: sci.electronics
From: aab@cichlid.com (Andy Burgess)
Subject: Tiny microphones used in hearing aids
Keywords: microphone
Organization: SIlma Inc.
Date: Thu, 16 Apr 92 22:21:46 GMT

I am posting this for someone who does not get sci.electronics.
Don't reply to me, reply to him.
Andy
--------------------------------------------
From: Robin.Salmansohn@f715.n273.z1.fidonet.org (Robin Salmansohn)
Subject: Special Microphone needed


>I would like to obtain the company name for those 
>tiny microphones used
>in the manufacture of the all-in-the-ear hearing 
>aids. Microphone to be
>(potentially) used in a cardiac pacemaker (Investigational Device).

Please email replys to:
Robin.Salmansohn@f715.n273.z1.fidonet.org


-- 
Andrew A. Burgess 
aab@cichlid.com 
voice (408) 335 4779
Newsgroups: sci.electronics
From: berger@atropa (Mike Berger)
Subject: Re: oscilloscope manual needed
Organization: University of Illinois at Urbana
Date: Mon, 13 Apr 1992 21:12:29 GMT

ce3wa3bc@maccs.dcss.mcmaster.ca (Tom Nosella) writes:
>I am wondering if some 
>one can help me?  I bought 2 oscilloscopes used from the university i attend, but there werent any manuals with them.  They are the same scope , namely Tektronics modem RM-503 rackmount scopes.  I am desperately trying to find a manual for them, i called Tektronics, but they were unable to help me find one.  If anyone could suggest where i look, or someone may have one lying around that i could pay for a copy of, please let me know.  I need a manual to service these machines.
*----
You can probably find one from a used equipment dealer, but Tektronix
generally has all their out-of-print manuals available on microfiche
for a nominal price.  Did you ask them about fiche?
--
	Mike Berger
	Department of Statistics, University of Illinois
	AT&TNET     217-244-6067
	Internet    berger@atropa.stat.uiuc.edu