HDTenEightyP/NetNews huggingface dataset:
From: jon_sree@world.std.com (Jon Sreekanth)
Subject: Re: Voice/Modem Switch
Organization: The World
Date: Wed, 19 Aug 1992 16:52:20 GMT

In article <1992Aug19.024929.4021@u.washington.edu> newsman@milton.u.washington.edu (Chris Ricci) writes:


   I am seeking a solution to the following problem.  I am looking for a way to    run a BBS on the same phone line my personal calls come in on(Voice).  Being    the lowly poor college student, I have a limited budget, BUT.... I am a EE      student so I'm not an idiot and I could build a solution.  If anybody out there in computer land knows of any solution(Even one I'd have to build).  Could you  pleeeeeeeeeease... let me know. 


1. Get distinctive ringing, which goes by different names in different
Bell territories (Custom Ringing, Ident-a-ring, Smart Ring, Ringmaster,
or similar names). This service, which may have a set up charge and 
monthly fee from your local phone company, assigns a second 7 digit
number to you, and calls dialled to that number appear on the same
physical line you now have, except they announce themselves by a 
distinctive ring pattern. Instead of the standard 2 sec on - 4 sec off
pattern of standard ringing, the first additional number might 
sound like a split ring, like the British ring-ring ... pause ... ring-ring.
Then buy or hack up some hardware so incoming calls with that particular
ring pattern are directed to your modem. Or hack up your BBS software
so it only picks up calls with that ring cadence. 

2. Tell your modem callers to dial a touch-tone digit after dialling 
your 7 digit number. Your BBS callers should be instructed to use
the Hayes command atdt 555 1234 ,,,2,2,2. Each , creates a 2 second
wait. So after dialling your number, your caller's modem will wait
for a few seconds, then dial the digit 2 a few times. Now you can
buy or hack up some hardware that picks up incoming calls, has 
two outputs : phone and modem. It rings the former by default, 
and rings the latter if it sees the digit 2.

3. Tell your modem callers to go into reverse mode. The Hayes command
is atdt 555 1234 R. Their modem will dial your number, then emit the
high pitched (1KHz ?) tone. Buy or hack up some hardware that
picks up incoming calls, and listens for the tone.

IMHO, you're best off buying a commercial fax switch. Most of the 
better ones have three outputs, phone, fax and modem, and go 
for $100 - $150 if you shop around, especially check out mail order.
None of them are foolproof. The most transparent solution is #1
and commercial distinctive ring splitters should be $50 to $100.
 
If you decide to build hardware, you'll be re-inventing
the wheel, and it'll take you a few weeks. Depending on your
perspective, it could be an educational experience. 

/ Jon Sreekanth

Assabet Valley Microsystems, Inc.           |  Fax and PC products
5 Walden St #3, Cambridge, MA 02140         |  (617) 876-8019
jon_sree@world.std.com                      |
Organization: Queen's University at Kingston
Date: Thursday, 20 Aug 1992 20:01:47 EDT
From: <LEEK@QUCDN.QueensU.CA>
Newsgroups: sci.electronics
Subject: Pin outs of PLCC version of MC68882

I notice there are lower cost versions of MC68882 in the market these days.

I looked up my 68881/68882 User's Manual and the only package listed is
the PGA.  Does anyone out there has the pin outs of the PLCC chip ?  I want
to find out whether or not it would be pin compatible if I put the PLCC
chip into a PLCC socket and plug the socket into the PGA.

Thanks in advance.

K. C. Lee
Elec.  Eng. Grad. Student
Newsgroups: sci.electronics
From: tbbusser@uokmax.ecn.uoknor.edu (Tod B Bussert)
Subject: Identify:  STR 53041 - VGA Flyback IC
Organization: Engineering Computer Network, University of Oklahoma, Norman, OK, USA
Date: Wed, 19 Aug 1992 01:34:53 GMT


I am in the process of trying to repair my VGA monitor since my
flyback circuitry decide to go up in smoke.  I need to identify
an IC labeled:   
     STR
    53041
    9414

which is part of the flyback circuitry.  It appears to be a 7 lead
SIP package.

Since this is a used monitor, I do not know the manufactor since I
did not receive any information, nor is there any on the monitor
itself except for the label on the back of the monitor which says
Model No:  VC2.  If I knew the manufactor of this monitor it would
also be a great help.

Please email any responses and I will summarize.

Thanks in advance,
Tod
tbbusser@uokmax.ecn.uoknor.edu
Newsgroups: sci.electronics
From: clarke@acme.ucf.edu (Thomas Clarke)
Subject: Re: How hot can the 486-50 cpu run ?
Organization: University of Central Florida
Date: Fri, 21 Aug 1992 17:11:09 GMT

I quote from the Intel Air-Cooled Computing Chip Manual:

The case of the 486 shows a dull-red color at the maximum
dissipation rating for military service.  It shows
an orange-red color at the maximum dissipation rating for
commercial and amateur service.

-:-)
Thomas Clarke
Institute for Simulation and Training, University of Central FL
12424 Research Parkway, Suite 300, Orlando, FL 32826
(407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu
Newsgroups: sci.electronics
From: pnadj@ee.ubc.ca (NADJ PAUL)
Subject: LED "Power-indicators"
Organization: University of BC, Electrical Engineering
Date: Wed, 19 Aug 1992 08:05:32 GMT


I would like to build an LED indicator display similar to the ones found
on stero systems (flashing lights to measure power output).  The panel I
plan to build would have several banks of LEDs for several different
frequencies.

        ........  100 Hz
        ........    1 kHz
        ........   10 kHz

        (maybe a few more banks).

My question is this: how do I get only one LED to light up when there is
minimal power, and then two when there is some more, and then three when...

This seems SOOOOO trivial but I can't figure it out.  Maybe I should sleep
on it some more.  Anyhow, I plan to use a condenser mic for input so I
don't have to "steal" power from my speakers.  Is this necessary in your
opinions.  The condenser has the advantage of making the device usable
for other things, though.

Also, if anyone has some neat ideas for fancy flashing light displays
(or something of the like) I would be interested in hearing about them.

        --Paul




-------------------------------------------------------------------------------
|  Paul Nadj:  UBC Electrical Engineering                  ------  Morbid     |
|            Starving Student                              O    |  games we   |
|  pnadj@ee.ubc.ca -- write me: I'm bored                 /|\   |  teach our  |
|                                                         / \   |  kids.      |
|  "If it wasn't for bad luck I'd have no                       |  Hmmm...    |
|  luck at all"              --Nikki Sixx                   ---------         |
-------------------------------------------------------------------------------

Newsgroups: sci.electronics
From: massoud@chemteca.sdsu.edu (Massoud Ajami)
Subject: Re: AC zero cross detection?
Organization: San Diego State University
Distribution: sci
Date: Sat, 22 Aug 1992 16:13:44 GMT

In article <1992Aug21.222100.15735@sics.se> boortz@sics.se (Kent Boortz) writes:


>Hi,

>I will interrupt a microcontroller at 220V AC zero crossing time to reset
>an internal timer. Any ideas of a simple but reliable zero crossing detection
>circuit? The triggering has to be isolated with a optocoupler. The 220V
>will beside driving a halogen lamp be transformed down to 9V AC to drive
>the processor etc. Could I detect the zero crossing point on the 9V side
>or will there be a phase shift because of the induction in the transformer
>and the load?

>Any ideas?

>Kent Boortz
>boortz@sics.se
>--
>Kent Boortz
>boortz@sics.se

You can use CA3059 runing in continuous mode cascaded with H11L series 
optoisolator. The CA3059 can be used in low voltage, but phase shift of 
the transformer is load dependent, if such shift exists, use another 
small transformer and you may not need to use optoisolator.


Peace and Prosperity!
  ---==< 110 >==---
Organization: University of Illinois at Chicago
Date: Friday, 21 Aug 1992 10:37:51 CDT
From: <U09207@uicvm.uic.edu>
Newsgroups: sci.electronics
Subject: variable current source

From: Vahe Caliskan

I am looking for a circuit that can be used to control the current
delivered to a soldering iron tip from the ac line. The tip is not a
regular heating element as in hand held soldering irons but it is the
wire type found in
the "handgun" style soldering irons. Anyway, I was looking for a simple
circuit employing SCRs, Triacs, Diacs that can do the job. I am trying to
control the current from 3 to 8 amps. Any suggestions? Please email to me.
Any help would be greatly appreciated since I am not very familiar with
circuits that use the above mentioned devices.

Thanks in advance.

Vahe Caliskan (vahe@uicbert.eecs.uic.edu)
Newsgroups: sci.electronics
Subject: Guided Vehicles
From: kwilli@elaine.ee.und.ac.za (KEVIN WILLIAMS : THIRD)
Date: 13 Aug 92 11:55:24 +0200
Organization: Electronic Eng., Univ. Natal, Durban, South Africa
Summary: Guided Vehicles

I am currently investigating circuitry to provide automated guidance to a 
model car by means of a wire taped to the floor carrying some high frequency 
signal which is detected by sensors on the car. This is used to provide 
steering information etc.

Does anyone know if this is the best way of doing this? If anyone has tried 
this, I would really like to know about some of the problems or successes 
you've had!

Thanks!!!
Newsgroups: sci.electronics
From: wb8foz@skybridge.SCL.CWRU.Edu (David Lesher)
Subject: Re: GPS Availability
Reply-To: wb8foz@skybridge.scl.cwru.edu (David Lesher)
Organization: NRK Clinic for habitual NetNews abusers - Beltway Annex
Date: Sun, 16 Aug 92 18:13:55 GMT

Others said
# Nope.  Selective Availability (the deliberate pseudorandom "fuzz" introduced
# by the DoD) is very much back in force.  Pity.


I've never really understood this. What possible difference does
several hundred meters error make to either:
	a) an incoming 3 gigaton warhead

	b) or even an [also incoming] t-52 tank

I'm sure I'm missing something obvious here......

--
A host is a host from coast to coast..wb8foz@skybridge.scl.cwru.edu
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
From: miked@syscon.rn.com (Mike DeMetz)
Newsgroups: sci.electronics
Subject: Re: NiCa battery
Date: 18 Aug 92 13:08:45 GMT
Organization: Syscon Corporate Headquarters - South Bend, IN USA

au240@cleveland.Freenet.Edu (Ari Pitkanen) writes:


>What happens when I discharge a NiCa battery (4 cells) completely empty.
>Will one of the cells be charged in opposite direction or destroyed in
>some other way ?
It is possible one cell will reverse charge if they are not matched cells.
Usally you try not to go below 1.1 volt per cell.
Newsgroups: sci.electronics
From: BACS Data Communications Group <commgrp@silver.ucs.indiana.edu>
Subject: Sound-powered telephones
Organization: Indiana University
Date: Mon, 17 Aug 1992 22:50:22 GMT

You can make sound-powered telepones from "piezoelectric speaker 
elements" available at Irish Electronics (Ray D. O'Shack :-), part # 
273-091 ($2.49).  Just connect one to each end of a pair of wires.  
It's a great toy for kids, and may have "real" applications too.

Speech is fully intelligible despite a jagged frequency-response 
containing many resonances.  The device is manufactured by MuRata of 
Japan.  

These devices are compatible with U.S. Army TA-1/PT sound-powered 
field telephones.  They are also the same diameter as the microphone 
in the TA-1, and can be used as a field-expedient replacement. 
Humidity tolerance and range have not been determined.  The TA-1's 
electromagnetic transducers are somewhat delicate and will break 
internally if subjected to mechanical shock (like dropping the phone 
on a hard surface).

--

Frank Reid     W9MKV     reid@ucs.indiana.edu
From: wb9omc@dynamo.ecn.purdue.edu (Duane P Mantick)
Newsgroups: sci.electronics
Subject: Re: "Chip chat" AY-3-1015
Date: 19 Aug 92 22:20:42 GMT
Organization: Purdue University Engineering Computer Network

byron@cc.gatech.edu (Byron A Jeff) writes:

>In article <10666281.14.714208429@eng2.eng.monash.edu.au> 10666281@eng2.eng.monash.edu.au (KEVIN PRATER) writes:
>>I ve just dug out an old project for an xy plotter
>>from electronics and wireless world dec 1984.
>>It had a chip marked AY-3-1015 which they said was a uart chip.
>>can I substitute a NS16450 at uart for this?

>I don't think so. One of the features of the above UART is that it could
>be hardwired into whatever configuration your needed. Most up to date

	As an alternative, try a Western Digital TR1863-PL.  We use
them in our LearSiegler adm5 terminals and they work just dandy.

Duane Mantick
Engineering Computer Network
Purdue University
Newsgroups: sci.electronics,rec.audio
From: bobk@sequent.com (Bob Krull)
Subject: Re: CDs, Pens and Blue Lasers.
Organization: Sequent Computer Systems Inc.
Date: Wed, 12 Aug 92 20:02:11 GMT

In article <x13m--c.rcain@netcom.com> rcain@netcom.com (Robert Cain) writes:
>jrm@gnv.ifas.ufl.edu writes:
>: In article <11477@optilink.UUCP>, manley@optilink.UUCP (Dave Manley) writes:
>: > +--------------------------------------------------------------+
>: > + The SONIC CLARITY(tm)  CORP., LTD. supports a drug-free      +
>: > + workplace and requires that all offers of employment         +
>: > + be contingent on satisfactory pre-employment drug test       +
>: > + results.                                                     +
>: > +--------------------------------------------------------------+
>: 
>: 	Well, you won't get rich on MY dollars. I cannot support
>: 	any company that has caved-in to the current anti-drug
>: 	propaganda to the extent of violating the civil-rights
>: 	and common dignity of its employees with substance
>: 	tests. 40-odd years ago, it would have been loyalty-oaths,
>: 	or proof of non-Jewishness, non-Blackness or anti-communism.
>: 	Same evil, different name. 
>: 
>: 	Just my humble perspective on creeping fascism ...
>: 
>: 	-- Jim Mason
>
>Nor mine. Extremely well said Jim.  This has to stop.
>
>Bob
>
>-- 
>
>Bob Cain    rcain@netcom.com   408-358-2007

Add my vote to that!
-Bob Krull
bobk@sequent.com
From: rkarlqu@hpscit.sc.hp.com (Rick Karlquist)
Date: Wed, 19 Aug 1992 16:06:51 GMT
Subject: Re: Beginners Question: RAS, CAS, and Refresh?
Organization: Hewlett-Packard, Santa Clara, CA
Newsgroups: sci.electronics

When you enable RAS on a DRAM, it refreshes the entire row associated 
with that address.  So you merely have to do a RAS on each row every
whatever milliseconds.  For a 1 MEG memory, this is only 1024 operations,
instead of 1048576 operations!  You do not have to use CAS for refresh.
You only use that to actually access a bit.

Rick Karlquist
rkarlqu@scd.hp.com
From: thomasn@tekig5.pen.tek.com (Thomas M Nathe)
Newsgroups: sci.electronics
Subject: Re: floating (?) pulse source -> info wanted
Date: 20 Aug 92 03:41:25 GMT
Organization: Tektronix, Inc., Beaverton,  OR.


Well I don't know what your budget is, but Tek does make the HFS 9000 series
precision pulse generators. Fully programmable pulse trains to 630 Mhz rise
times down to 5nS, ect, ect... 

If money isn't a probelm, get ahold of your local Tek sales rep for a demo.
(Just so happens that I work on the critter, niffty piece of electronics. If 
I do say so myself ;> ).
Newsgroups: sci.electronics
From: jon_sree@world.std.com (Jon Sreekanth)
Subject: Re: Why are 8 bit TTL binary counters so hard to find???
Organization: The World
	<1992Aug14.033406.19291@julian.uwo.ca>
Distribution: na
Date: Sat, 15 Aug 1992 16:34:46 GMT

In article <1992Aug14.033406.19291@julian.uwo.ca> wlsmith@valve.heart.rri.uwo.ca (Wayne Smith) writes:


   In article <JON_SREE.92Aug13214342@world.std.com> jon_sree@world.std.com (Jon Sreekanth) writes:

   >Why is it important to get an 8 bit counter in one package, as 
   >opposed to tying two 4-bit counters together ? 

   I already have a prototype made of 4 independant 16 bit counters, and
   working with 4 bit counters (74F161) are a pain.

   What I really would like is 4 addressable independant 16 bit counters 
   running off a single clock (no load register needed) with a common
...

I guess it's one of those things that falls through the cracks. It's
too big and too specialized for a 74xx series part. A PLD may be 
expensive or slow or consume too much power. A low end gate array might
be over-kill. Oh, well. In a production setting, even a handful of
74xx series glue chips can be fairly closely packed, using surface mount
parts and using both sides of the board. Directly bonding the die onto
the PC board is also becoming more popular. 

/ Jon Sreekanth

Assabet Valley Microsystems, Inc.           |  Fax and PC products
5 Walden St #3, Cambridge, MA 02140         |  (617) 876-8019
jon_sree@world.std.com                      |
Newsgroups: sci.electronics
From: kingpin@world.std.com (Joe Smooth)
Subject: EPROMS for sale
Organization: The World Public Access UNIX, Brookline, MA
Distribution: sci
Date: Fri, 14 Aug 1992 08:03:53 GMT


For sale: 6 (six) 27512 erased EPROMS

	$15 + shipping

		If interested, email: kingpin@world.std.com

Newsgroups: sci.electronics
From: aaronb@suhana.analog.ingr.com (Aaron B.)
Subject: NTSC color processing Chip?
Keywords: Color TV
Reply-To: aaronb@suhana.analog.ingr.com
Organization: Home Office Enterprise
Date: Thu, 20 Aug 1992 22:19:05 GMT

Does anyone know what kind of chip does the Radio Shack video enhancer use.
I need to do some color enhancement of video signals.  I saw one advertise
in DAK catalog.  If anyone know any special chip that does color enhancement
please E-mail me your reply.

I need something that will take baseband video signal.

Thanks in advance

Aaron B
aaronb@suhana.analog.ingr.com
From: mendels@eniac.seas.upenn.edu (Jeffrey Mendelsohn )
Newsgroups: sci.electronics
Subject: DC voltage doubling question
Date: 17 Aug 92 11:56:33 GMT
Organization: University of Pennsylvania

Hi all.

Simple question - I hope.  I need to double the voltage in a DC circuit and
I do not have any power supply except the one in the circuit.
How do I do it?

Assuming this is too easy for you, let me then ask this question.
Given a single DC voltage supply of, say, 0.45 V, how do I double it?
The question being that I can no longer use diodes (right?).



						Thanks,
						Jeff Mendelsohn
						mendels@eniac.seas.upenn.edu
Newsgroups: sci.electronics
From: robcruic@intacc.uucp (Robert Cruickshank)
Subject: Re: Looking for a thermo-electric cooler....
Date: Fri, 21 Aug 1992 08:16:10 GMT
Distribution: na
Organization: Inter/Access' Matrix BBS

In article <ALAVIGNE.92Aug17092513@bmerh930.bnr.ca> alavigne@bmerh930.bnr.ca (Andrew Lavigne) writes:
>
>I'm posting this for a friend who is trying to build a CCD camera for his
>scope.  He wants to know where he can obtain a thermo-electric cooler for
>his CCD chip.  Its also known as a 'peltier cooling module'.  Does anyone
>know where these can be obtained and about how much they are???
>
>Any replies or hints appreciated...
>
>Thanks,
>Andrew
>alavigne@bnr.ca


Well, I just saw them for sale in Tokyu Hands, a big department store in
Tokyo, for the eqivalent of 50 bucks for one that was about an inch and a half
square. Also, I think that in the US, American Design Components has them a
lot cheaper, surplus. I don't have their address handy, but the advertise in
some of the hobbyist magazines, or someone else on the net might have it. If
not I could dig it up..

----rob
----
------------------------------------------------------------------------
Rob Cruickshank
robcruic@intacc.uucp
Inter/Access Artists' Center
Matrix BBS
Toronto, Canada
------------------------------------------------------------------------
From: walzer@inqmind.bison.mb.ca (Bruce Walzer)
Newsgroups: sci.electronics
Subject: List of San Jose area surplus electronic shops?
Date: Thu, 20 Aug 92 23:01:14 CDT
Organization: The Inquiring Mind BBS  1 204 488-1607

I remember that someone on here was nice enough to post a list of
San Jose area electronic surplus type establishments. If anyone
has this could they please mail it to me? I am going to be in the
area next week.

Please send mail to  bwalzer@muug.mb.ca  and not to the address
on the header.


Thanks,
Bruce
bwalzer@muug.mb.ca

walzer@inqmind.bison.mb.ca
The Inquiring Mind BBS, Winnipeg, Manitoba  204 488-1607
Newsgroups: sci.electronics
From: aaronb@suhana.analog.ingr.com (Aaron B.)
Subject: Re: Cable Television Descrambling
Reply-To: aaronb@suhana.analog.ingr.com
Organization: Home Office Enterprise
Distribution: sci
Date: Sun, 16 Aug 1992 00:41:36 GMT

In article <1992Aug15.145932.21272@dragon.acadiau.ca>, 880518l@dragon.acadiau.ca (Nelson Langille) writes:
|> Will this descrambler work with an antenna signal, or does the signal
|> have to come from the cable company?

Which descrambler are you talking about?  If the signal that you have is
scrambled by altering the sync, then there are a couple of descrambler
circuit that will restore the sync.  There is one published in Radio Electronics
May 1990 issue.  Some say it works without modification but there are a couple
of typos in the original article.

Aaron B

aaronb@suhana.analog.ingr.com
Newsgroups: sci.electronics
From: berger@atropa (Mike Berger)
Subject: Re: Craftsmanship is dying
Organization: University of Illinois at Urbana
Date: Mon, 17 Aug 1992 17:17:58 GMT

aescherm@iastate.edu (A Person of Awareness) writes:
>The way that I solve the problem of New is Bad/Old is Good is to buy those
>old things that were good and fixable and those new things that I don't care
>if I can or can't fix.

>Really, if I'm buying a $5 pair of walkman headphones, who cares if they
>break?  BTW I actually had a Radio Rip Off Store sales-droid offer me a plan
*----
I care.  Don't you have anything that operates in a way you
particularly like, and wish you could keep?  I prefer the controls
on my old VCR to the new one.  My friend loved his cheap, folding
headphones, and has been unable to find a replacement as good.
--
	Mike Berger
	Department of Statistics, University of Illinois
	AT&TNET     217-244-6067
	Internet    berger@atropa.stat.uiuc.edu
Newsgroups: sci.electronics
From: tchannon@black.demon.co.uk (Tim Channon)