HDTenEightyP/NetNews huggingface dataset:
From: jvp@juliet.ll.mit.edu ( Jim Pieronek )
Subject: Re: Parallel and Serial Ports
Organization: M.I.T. Lincoln Lab - Group 43
	<1992Apr7.004707.29179@athena.cs.uga.edu>
	<1992Apr9.223816.1466@panix.com>
Date: 10 Apr 92 11:02:24

In article <1992Apr9.223816.1466@panix.com> schuster@panix.com
(Michael Schuster) writes:

   I've noticed on the specs of the Trantor parallel port-to-SCSI adaptor that
   writes (i.e. output from the parallel port) are twice as fast as reads
   ("input" via the parallel port). Does this mean the "input" is kludged?

In a word, yes.  If you eyeball the pinout for the printer port pinout
you will notice that there are 8 dedicated output lines, (DATA 0-7)
and 4 dedicated input lines (BUSY, PAPER OUT, etc.)  So your SCSI
gizmo must be using the 8 output lines for writing and the 4 input
lines for reading.  Many computers, but not all, can use the 8 data
lines bidirectionally.  Some of software for the devices made for
printer ports test this when they are initialized and use it that way
if possible, otherwise they fall back to the 8 out and 4 in
configuration.

- 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: wtm@uhura.neoucom.edu (Bill Mayhew)
Newsgroups: sci.electronics
Subject: Re: TTL level control of 120VAC power
Date: 13 Apr 92 01:51:17 GMT
Article-I.D.: uhura.1992Apr13.015117.6037
Organization: Northeastern Ohio Universities College of Medicine

The way to go is to use an optically isolated solid state relay.
New, these things go for about $15-$20.  Ratings vary, but are
typically in the 10amp, 120v range.  Input trigger is 3-32 vdc at
about 30 mA, give or take.  All the SSRs (solid state relays) I've
used have come with zero crossing, snubbing, etc built in.  Greatly
simplifies project building.  At hamfests, SSRs usually seem to go
for about $5.  Check out a Pioneer, Newark,... catalog for
details.

-- 
Bill Mayhew      NEOUCOM Computer Services Department
Rootstown, OH  44272-9995  USA    phone: 216-325-2511
wtm@uhura.neoucom.edu   (140.220.1.1)
From: berger@atropa (Mike Berger)
Newsgroups: sci.electronics
Subject: Re: Cable TV ch 3 shifted to ch 65?
Date: 13 Apr 92 21:20:33 GMT
Article-I.D.: ux1.1992Apr13.212033.25355
Organization: University of Illinois at Urbana

bae@hplsdll.col.hp.com (Bruce Erickson) writes:
>I am looking for a circuit which would take cable tv inputs
>(one is the regular cable, the other the output of the converter
>box on channel 3) and output the regular cable up to (about) 
>channel 60, then put the converter channel on a high channel
>(say 65).  

>I know Radio Shack sells a block converter to shift cable TV channels
>to non-cable channels, but I need a way to not only shift the channel
>but to merge the two signals together.
>Basically I am looking for a way to use the cable box for HBO, and
>yet still allow my VCR's tuner to tune in HBO plus any other non-
>scrambled channel...

>Anybody have this or know where I could find one?  Or, for that matter,
>if anybody has a box to do that for sale?
*----
Scientific Atlanta has these for sale for a few thousand dollars.
You can occasionally find them on the surplus market for less.
--
	Mike Berger
	Department of Statistics, University of Illinois
	AT&TNET     217-244-6067
	Internet    berger@atropa.stat.uiuc.edu
From: cnmne@plex-1 (Chris Ellinger)
Newsgroups: sci.electronics
Subject: Source for miniature cable wanted
Date: 2 Apr 92 18:14:22 GMT
Distribution: usa
Organization: Plex-1, Michigan's Public Access Usenet Gateway  (Ann Arbor).

I'm looking for a source for small quantities (50-100') of miniature,
multi-conductor cable.  I need 4-5 conductor, stranded, 30-32 AWG, 
shielded, jacketed cable that is designed to be very flexible.  The sources 
I have contacted (Cooner, New England) make this stuff on demand with 1000' 
minimum orders.  Anyone know of a source for small quantities from stock?
Thanks in advance.

Chris Ellinger
Ann Arbor, MI
Xref: sparky sci.electronics:8269 rec.music.cd:3927 rec.audio:7194
From: nemeth@helix.Eng.Sun.COM (Les Nemeth)
Newsgroups: sci.electronics,rec.music.cd,rec.audio
Subject: Re: requesting CD player advice
Date: 9 Apr 92 23:39:32 GMT
Organization: Sun Microsystems, Mt. View, Ca.
NNTP-Posting-Host: helix

In article <1992Apr8.091944.19345@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
  
>>Some respondents have claimed that because any loudspeaker is so much 'worse'
>>than a CD player (and I'd love to see him/her explain precisely what _that_ is
>>supposed to mean) even if there might possibly be differences between CD
>>players you'll never hear them.  This is arrant nonsense.

>The typical loudspeaker generates between 4 and 7% distortion. A CD player
>at .03% distortion is at least 200 times better. If you can tell differences
>of 1/200th in distortion, you qualify as one of the golden eared.

Gary,

What you are missing here is the fact that distortion is of no relevance
in this equation. There are going to be better and/or worse players than
others regardless of price. Sound quality of the CD player has to do with
how well the player converts the data from digital to analog. Therefore,
it is in your best interest to buy the player with the most oversampling
per dollar spent. It has been proven that, the more oversampling a player
has, the better it is at reproducing the sound faithfully.

A CD player can have .0001% distortion, but if it has a tinny sound who the
heck is gonna buy it. Probably the guy that doesn't take the time out to 
compare one player to the other...  Conversely, if another player has .001%
distortion but has a muddy sound, who the hecks gonna want it either. What
we are looking for is the one that sounds the most natural, regardless of
the distortion level, provided it's not around 10%.

/Les

--
-> Aragon,Camel,Edhels,Eloy,Enchant,Fish,Focus,FrozenGhost,Gabriel,
-> Genesis,Giraffe,Iskander,iQ,Kansas,ManfredMann,MarcJordan,Marillion,
-> Pallas,Parsons,Pendragon,PinkFloyd,Pulsar,Rush,Saga,SimpleMinds,Solaris,
-> TalkTalk,TearsForFears,Triumvirat,Tull,UK,Yes .......... nemeth@Eng.Sun.COM
From: klimasewski@fccvde.enet.dec.com (Ken Klimasewski)
Newsgroups: sci.electronics
Subject: PROMPRO 8 software
Date: 10 Apr 92 17:56:15 GMT
Organization: Digital Equipment Corporation


I am looking for some software that will allow me 
to use my LOGICAL DEVICES Prompro-8, prom programmer with my 
computer.

The computer is a IBM clone 386 

LOGICAL DEVICES sells a program called PROLINK but it is for the 
PROMPRO-8X and does not support the earlier version 8.



                                     thanks,
                                       Ken
                                       508-467-2663


Ken Klimasewski	klimasewski@fccvde.enet.dec.com
		--or-- ...!decwrl!fccvde.enet.dec.com!klimasewski
		--or-- klimasewski%fccvde.dec@decwrl.dec.com
Newsgroups: sci.electronics
From: medin@catbyte.b11.ingr.com (Dave Medin)
Subject: Re: Ohm's law for AC?
Reply-To: medin@catbyte.b11.ingr.com
Organization: Intergraph Corporation, Huntsville AL
Date: Tue, 14 Apr 1992 23:09:43 GMT

In article <1992Apr13.170559.8310@athena.cs.uga.edu>, mcovingt@athena.cs.uga.edu (Michael A. Covington) writes:
|> What was the impedance at the end of the cable?  That is, what were you
|> using for a load?
|> 
|> The circuit looks like this:
|> 
|>              R1
|>        -----//////--------+
|> Signal                    / R3
|> source                    /
|>        -----//////--------+
|>              R2
|> 
|> Here R1+R2 is the resistance of the cable, and R3 is the resistance of the
|> load (the thing you're measuring the voltage at).
|> 
|> Let V represent the voltage at the source.  Then the voltage across R3
|> will be   V * R3 / (R1 + R2 + R3).
|> 
|> If R1+R2 = 5 ohms and R3 = 10 million ohms (the normal input impedance of
|> a digital multimeter) then R1+R2 will be negligible.

I think the poster may have wanted the AC factors to figure into the
frequency response considerations. At audio frequencies, the cable
length versus frequency response is governed more by the
impedancse of the source and load, along with the capacitance of
the cable. As noted above, with a high impedance *AC* load and
a relatively low source impedance (figure 1K ohm for most consumer
outputs), there will be little change in signal amplitude noted
over 5 meters of cable. With a low-impedance load there will be
even less *frequency dependent* loss in the audio range.

To approximate the loss for short cables (less than 100 feet or so),
take the above diagram, but make R1 the source impedance, R3 the
cable impedance (round-trip, DC), and R2 the load impedance. Now,
parallel the total cable capacitance across R2 and measure across R2
with a scope or similar AC device (note that most DVMs
have decreasing AC response above 1 KHz).

The real term of the capacitive reactance is given by:

	Z = 1/(2* pi * frequency * C)

Use this value as "resistance" in the DC Ohm's Law equations. Note
that although the capacitance is distributed along the length of
the cable, we're treating it as if it were all lumped in the
worst possible location. The results will show that for low impedance
sources, a reasonable cable length is no problem from the signal
conduction standpoint. It may pick up more interference or noise the
longer it is, though...

Inductance is not much of a factor at audio frequencies, using
regular cable.

-- 
------------------------------------------------------------------------
     Dave Medin				Voice: (205) 730-5812 (w)
  Intergraph Corp.			       (205) 837-1174 (h)
     M/S CR1104
Huntsville, AL 35894-0001	Internet: medin@catbyte.b11.ingr.com

   *********Everywhere You Look...(at least around my office)***********

       *The opinions here are strictly my own (or those of my machine)
From: noble@hplvec.LVLD.HP.COM (Bob Noble)
Date: Fri, 10 Apr 1992 22:25:22 GMT
Subject: Re: radar traps
Organization: Hewlett-Packard Co., Loveland, CO
Newsgroups: sci.electronics

Always go to court.  Always!

Go to the first (plea) hearing.  The cop may have failed to submit his
report.  Case dismissed.

 -or-

The DA may take a plea bargain.  This usually requires a visit to a
lawyer for coaching (traffic specialists are at the bottom of the food
chain = cheap).  You may end up with probation and a clean record at the
end of 6 months.

Take it to trial.  The cop might not show.  Case dismissed.  (Worst case is
you pay the fine plus court costs; a small price to pay for the knowledge
that you kept the cop cooling his heels for a couple of hours.

NOTE:  If you just send in your ticket with the fine, the court will
accept it EVEN if the cop never submitted his paperwork; you hang yourself.

I've had 2 tickets in the last 10 years.  The first one I just paid; I
did not know what the system was, and did not think I had the time.  On
the second one, I took it to trial (just because the cop was rude) - and
won.  Feels so good!
From: michaeln@hpcvnb.CV.HP.COM (Mike_Nason)
Newsgroups: sci.electronics
Subject: Re: Phone Line Audio Question
Date: 12 Apr 92 08:34:18 GMT
Article-I.D.: hpcvnb.25470002
Organization: Hewlett-Packard Co., Corvallis, Oregon


   excuse me but i have a dumb question.....since its going to be mono coming
over the phone and since your probably using 600 ohm input to the mixing 
pannel, why don't you just buy a "cheap" ham phone patch....
  i think the cheapest ones i've seen lately are about $59. from mfj. and
there usually listed in the mfj adds in most of the ham magizines? 
   i told you it was a dumb question. 
            all my comments are my own. no one else would own up to them. 
Newsgroups: sci.electronics
From: danube@dirac.physics.sunsyb.edu (Dan Koller*)
Subject: Re: Engine Knock Sensor
Organization: Institute for Theoretical Physics, SUNY at Stony Brook
Distribution: na
Date: Tue, 14 Apr 1992 12:50:33 GMT

In article <#+8tqjm@rpi.edu> richtt@aix.rpi.edu (Timothy G. Richter) writes:
>I need to determine the output of an engine knock sensor.  As far as I
>know, the knock sensor is a piezo-electric "microphone" which "listens"
>for knock.  Knock occurs at 6.5kHz, and the knock sensor is (I'm guessing)
>a narrow-band pass filter at 6.5khz.  Using this assumption, I'd expect
>to get a 6.5kHz sine wave at the output when the sensor is exposed to knock.
>I can't get engine under load to create knock, so I'm going to try using
>a speaker.  Does anyone know how these sensors operate and what the output
>is?  This is going to be connected to a microcontroller (68HC16) to help
>with fuel injection and spark timing.
>


   I'm no expert on engine knock, so wait for the experts.  In any case,
my guess is that engine knock produces a very complicated waveform, with
many harmonics.  After all, if it were just a 6.5Khz sine wave, it 
probably wouldn't cause damage to the engine!  6.5Khz might be optimized
for some characteristic of the block.
   I would recomend getting your engine to knock a bit.  Use real cheap
gas (Sunoco 86 octane), or advance the timing a few degrees.  That's a 
simple reversible matter and it won't cause engine damage unless you 
drive that way continuously.  If you can't adjust anything, try flooring
the pedal on a cold morning while going up hill, shortly after starting
the car.  The choke should be set so you'll get a rich mixture and it
might knock.  Try taping the sound.
   Let me know about the results you get.  A properly working engine knock
sensor might have saved my last Shitty Chevy.  On the other hand, it was
a Celebrity with a Fiero 4 cylinder engine so nothing could save it...
Good luck.
							Danube
From: kent@cc.tut.fi (Kentt{l{ Marko)
Newsgroups: sci.electronics
Subject: What's GEC 8807A ???
Date: 14 Apr 92 06:42:29 GMT
Organization: Tampere University of Technology, Finland


I've got this strange Z80 based board ('MLGMBH 16214 CPU-Z82 E0081' with a
384 Kb RAM card 'E 1032 MLGMBH RAM 384 16082') and there's one IC that I
haven't yet figured out: GEC 8807A.

Anybody know this IC or this micro ???

Thanks, Make
-- 
.............................................................................
: MAKE MY DAY : Marko Kentt{l{  TTKK/AuTek : Paununkatu 5  :    FINLAND -   :
:     or      :   kent@lehtori.cc.tut.fi   : 33700 Tampere :   THE FUNLAND  :
:   180 ov.   : MK102142@RAPOLA.cc.tut.fi  : Finland       : WITH FINLANDIA :
Newsgroups: sci.electronics,comp.dsp,sci.engr.biomed,sci.math
From: roth@gauss.enet.dec.com (Jim Roth)
Subject: Re: quaternians, tracking, 3 dimensions
Organization: Digital Equipment Corporation
Date:  9 APR 92 20:15:39    


A surprisingly useful reference on this appeared in the July 1985
ACM Siggraph proceedings:

	Ken Shoemake
	_Animating Rotation with Quaternion Curves_
	pp 245-254

Vol I of Graphics Gems also contains a brief discussion.

- Jim
From: schuster@panix.com (Michael Schuster)
Newsgroups: sci.electronics
Subject: New Japanese Coax Power Plug
Date: 14 Apr 92 12:47:07 GMT
Distribution: na
Organization: PANIX - Public Access Unix Systems of NY

New Japanese portable radios feature a standardized coaxial power connector
which is color coded according to voltage (e.g. for the new SONY shortwave
portables yellow means 6V). They are center pin positive and form factor
INCOMPATIBLE with every 'universal adaptor' presently sold. The barrel
appears to be 4MM as opposed to 2.5 or 5mm+ sizes presently used, and
the center pin is VERY LARGE compared to the relatively thin barrel size.

Anyone have a source for these things?
-- 
_______________________________Mike Schuster________________________________
NY Public Access UNIX: schuster@panix.com        | 70346.1745@CompuServe.COM
The Portal (R) System: schuster@cup.portal.com   | MCI Mail,GEnie: MSCHUSTER
Newsgroups: sci.electronics
From: <alan>@me.utoronto.ca
Subject: Specs for a MAXTOR XT2190
Summary: Need help with MAXTOR XT2190
Keywords: MAXTOR, DRIVE, SPECS
Organization: University of Toronto, Department of Mechanical Engineering
Distribution: sci
Date: 13 Apr 92 16:34:35 GMT

I want to use it in a PC to make Backups of a Network.  I have looked
all over for the jumper settings, but cannot find them.  If you have 
some information on these drives I would appreciate hearing from you
I can be E-Mailed at :     milner@ecf.utoronto.ca

thanks
From: v064mb9k@ubvmsb.cc.buffalo.edu (Neil Gandler)
Newsgroups: sci.electronics
Subject: DS1267 dual digital potentiometer I.C. from Dallas semiconductor
Date: 7 Apr 92 20:58:00 GMT
Organization: University at Buffalo
News-Software: VAX/VMS VNEWS 1.41

Has anyone used the DS1267 I.C. made by dallas semicomnductor in an
application to control volume in a stereo. The data sheets given to me
when I received three of these chips in the mail were not too helpfull.
They gave no example circuit. I payed $18 plus shipping for three of these
chips it would be a waste of money if I can't use them. Does anyone have
data sheets on this I.C. that gives an example circuit or does someone
know how I can use it. Its outputs are clearly described. Showing
the output as if it were a real dual potentiometer. But the inputs
are a reset pin, port data input/output and clock input.
I would appreciate any help or suggestions
  Thankyou
Newsgroups: sci.electronics
From: elia@aelle.cs.odu.edu (Lee Elia)
Subject: Re: How to ease drop on cord-less phones.
Organization: Old Dominion University Dept. of CS, Norfolk VA
Date: Tue, 7 Apr 1992 06:25:56 GMT

In article <sehari.702511268@vincent1.iastate.edu> sehari@iastate.edu (Babak Sehari) writes:
>---
>My friend have a AT&T cord-less phone. Once, when I was playing with a receiver
>to search for odd frequencies, I picked up his phone conversation at 15.2MHz.
>With a little bit of hacking around I found that It was the second harmonic,
>that I was receiving.  The original frequency is 7.51MHz.  It was modulated 
>with the AM format.
>
>I thought this information might be useful for electronic hackers; therefore,
>I decided to share it with you.
>
>                     With highest regards,
>                         Babak Sehari.

An older generation of cordless phone used frequencies around 1.7 mHz and
49 mHz.  Current generation cordless phones use:

         BASE STATION             HANDSET 
	ch 1	46.61 paired with 49.67 mHz
	ch 2	46.63 paired with 49.845 mHz
	ch 3	46.67 paired with 49.86 mHz
	ch 4	46.71 paired with 49.77 mHz
	ch 5	46.73 paired with 49.875 mHz
	ch 6	46.77 paired with 49.83 mHz
	ch 7	46.83 paired with 49.89 mHz
	ch 8	46.87 paired with 49.93 mHz
	ch 9	46.93 paired with 49.99 mHz
	ch 10	46.97 paired with 49.97 mHz

All of these are FREQUENCY MODULATED.  Also, there seems to be a move a foot
to permit additional channels spaced between the current ones...watch for
more on that.

THE ELECTRONIC COMMUNICATIONS PRIVACY ACT SAYS THAT IT IS ILLEGAL TO
LISTEN TO THE BASE STATION FREQUENCY, BUT IT'S OKAY TO LISTEN TO THE
HANDSET FREQUENCY.  

In practice, there is no way to enforce that, but you should know it if 
you plan to listen.  Violations of this provision of the ECPA are
pretty much undetectable. 

Best Wishes,

Lee

-- 
Lee Elia                | There are at least two kinds of games.  One could be 
Old Dominion University | called finite, the other infinite.  A finite game is 
elia@xanth.cs.odu.edu   | played for the purpose of winning, an infinite game 
my opinions, mine alone | for the purpose of continuing the play. -JPC
From: Jeff.Lindstrom@ofa123.fidonet.org (Jeff Lindstrom)
Newsgroups: sci.electronics
Subject: Info on iron-on PCBs??
Date: Mon, 13 Apr 92 04:13:04 PDT
Organization: Universal Electronics Inc. (Public access BBS)

AP>I missed saving the fairly recent thread on iron-on PCBs, and now I
AP>need the data. Could someone email me on this please?
AP>    - Andrew Palfreyman

  Amazing timing.  I just learned about this last week.

The distributor's name and address is:

     Meadowlake Corp.
     (516)757-3385
     25 Blanchard Dr.
     Northport, NY  11768

The product is:  Tec-200 film

It is a clear acetate and comes as 10 8"x10" sheets for $7.50.

Generate your 1X artwork and put it through the copier with the
 acetate in the paper tray.

Clean the PCB with 600 grit sandpaper or soapless steel wool
  or use denatured aclohol to clean the soap from a soapy steel
  wool pad.

Slap on PCB and use a thin cloth between the iron and acetate

Set the iron for 270-280 Fahrenheit (Cotton)

Iron for 2-2.5 minutes

Let cool and peel off film.

The PCB is now ready to etch with Ferric Chloride.

___
     Amig

--  

Jeff Lindstrom
Internet: Jeff.Lindstrom@ofa123.fidonet.org
Compuserve: >internet:Jeff.Lindstrom@ofa123.fidonet.org
From: Cliff_Lum@mindlink.bc.ca (Cliff Lum)
Newsgroups: sci.electronics
Subject: Re: PC parallel port
Date: 16 Apr 92 23:41:23 GMT
Organization: MIND LINK! - British Columbia, Canada
Distribution: world

> Boo! writes:
> 
> Msg-ID: <skg0bINNnmv@matt.ksu.ksu.edu>
> Posted: 16 Apr 92 18:11:23 GMT
> 
> Org.  : Kansas State University
> 
> 
>         Does anyone how to write and read to/from the parallel port
> of a IBM AT/XT and other machines. I posted this question on
> comp.sys.ibm and got no response. I would like to connect an intrument
> to the parallel port and use the port to read and write data and control
> it. Thanks..

I posted this inforamtion in another group also. Try getting this :
"Interface Circuit for Printer Port"
LAR-13950, from NASA Tech Brief:
 the purpose of this device is to convert any existing printer port on an IBM
pc/xt/at .... to a general purpose 8 - bit data, 16 bit address bus that can be
interfaced to a number of devices.
request LAR_13950 from:
NASA STI Facility
Manager , TU Division
P.O. Box 8757
Baltimore, MD 21240-0757

Info obtained from the computer Applications Journal Issue #25
From: JDB6@psuvm.psu.edu (John D. Balogh)
Newsgroups: sci.electronics
Subject: Re: masers from magnetrons
Date: 12 Apr 92 01:43:54 GMT
 <1992Apr11.134459.7224@udel.edu> <1992Apr11.194650.18694@willamette.edu>
Organization: Penn State University

In article <1992Apr11.194650.18694@willamette.edu>, agulhati@willamette.edu
(Ashish Gulhati) says:
>
>Excuse MY ignorance too, but what's a magnetron (I do know what a MASER is
>supposed to be)?
>
>Ashish

From my consulting with Litton Industries (many moons ago) a magnetron
fires electrons from a negative voltage source towards a "spin chamber"
which has a magnetic field set up by a permanant magnet. When an electron
enters the field, it starts to spin (thus the name of that chamber).
There is a small slot (or a number of slots depending on the application)
that couple into the side of the spin chamber which let out an electric
field (negative electrons passing hole in grounded "maggie" cause a
varing waveform (frequency) that transfers energy out) into a waveguide.
The frequency can be varied (when the tube is first turned on) by changing
the physical size of the spin chamber with a "tuning slug" . The larger
the volume, the lower the frequency.

Related tubes in this family are the Klystron (no permanant magnets, just
a big electromagnet to spin the electrons) which can be modulated,
and the Traveling Wave Tube (TWT) which is actually an amplifier, but
uses similar physics to maggie and klyde.