HDTenEightyP/NetNews huggingface dataset:
From: josephc@cco.caltech.edu (Joseph Chiu)
Newsgroups: sci.electronics
Subject: Re: Big Brother Radio Shack
Date: 10 Nov 1992 20:30:10 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: punisher.caltech.edu

slmdj@cc.usu.edu writes:

>In article <BxBzJK.BqK@news.udel.edu>, bew@brahms.udel.edu (Ben Williams) writes:
>> 
>> I've just read this thread containing 50+ complaints about Radio Shack.
>> What I would like to know is:  Why do we have to shop at RS to get
>> electronic supplies?  Why aren't there other electronic stores in
>> competition with RS?

Sure there is...  Circuit City, The Good Guys, Silo, Sears, Montgomery Ward,
even Robinson's and May Company...

Oh, you mean for electronic components?  Well, when was the last time your
mother needed a 10K ohm resistor and a handful of 74LS00's?  I'm afraid
that at "onesies", there's not enough profit to make selling components
worthwhile unless you raise the price like RS does.

>>  I still would like the option at least to do business elsewhere.
>> You know, like maybe an electronics store where the salesmen know what
>> they are talking about...

All the EE's are busy getting good money designing stuff.

In some areas in California, there is a Fry's Electronics - they actually
do a pretty decent job of keeping their price low and their selection wide
enough...  But there's only one Fry's in the Los Angeles area.  (Fry's,
BTW, is sort of a K-Mart for electronic/tech hobbyists/pro's.  _B_I_G_! )

>> Ben Williams
>> bew@brahms.udel.edu

>us hobbyists around.  I have found my best (and cheapest) source of parts to be
>an electronics teacher I once had who works at the local vocational school...

If you have time, mail ordering parts is the best way.  And if you're into
electronics, there's no excuse for not ordering "common" parts and keeping
a stockpile.

And worst come to worst, I just scavenge discarded PCB's that I find
lying around the campus...
-- 
Joseph Chiu, Dept. of Computer Science, Caltech.    josephc@coil.caltech.edu
1-57 California Institute of Technology, Pasadena, CA 91126. +1 818 449 5457 
* Now running OS/2, the best software that $89 can buy! (I want TCP/IP/X!) * 
Newsgroups: sci.electronics
From: msunde01@mik.uky.edu (Mark  Underwood)
Subject: Re: 386 replacement chip
Reply-To: msunde01@mik.uky.edu
Organization: University Of Kentucky, Dept. of Math Sciences
Date: Fri, 6 Nov 1992 20:03:59 GMT

In article <1992Nov5.162651.7465@unislc.uucp> mgc@unislc.uucp (Marc  
Christensen) writes:
> Christian Ricci (newsman@stein.u.washington.edu) wrote:
> : I just saw an ad for an Intel built 80386 replacement chip called the 
> : RapidCAD Engineering CoProcessor.  It is supposed to give up to 70%  
improve-
> : ment for technical applications.  It comes with two chips.  One  
replaces 
> : the 80386 and one goes in the 80387 slot.  Any idea what this thing is  
and
> : how it speeds up the computer?
> : 
> The 80387 speeds up Floating Point OPs and selling you a
> new 80386 increases intel Profits ??
> 
> 
> Seriously I don't know I havent heard about it yet.
> It sounds more like marketing than Technology to me.
> The '386 may be optimized for Math operations.
> 
> Marc Christensen 
> What is the Half life of Pentium?

I read a review on the RapidCAD chipset in a recent  . . . Computer  
Shopper (?) - it was nestled in a review of PC CAD systems (may be where  
Ricci saw it.)  Apparently Intel DID optimize the '386 for math operations  
and the "387" component added some CAD-specific functions.  I'm writing  
this having read the review a week ago and being far from the magazine, so  
I may be wrong.  Apparently the magazine thought it was a good deal for  
someone who couldn't afford to upgrade the whole motherboard (??)  I don't  
know if it is worth what they want for it, but apparently the RapidCAD  
chipset did perform notably better than a standard 386/387 combination in  
the magazine's tests.

Clear as mud, huh?


--
Mark Underwood
EE Student, University of Kentucky
Lab Assistant, UK Library Microlabs
Internet address:  msunde01@mik.uky.edu

"Cogito, ergo Sum." - Descartes
"Non Cogito - poof!" - Anonymous
Newsgroups: sci.electronics
From: karkan@msdrl.com (Jim Karkanias)
Subject: Autodialer
Organization: Merck Research Laboratories
Date: Fri, 6 Nov 92 01:00:38 GMT

Does anyone know of a public domain or shareware program that would let me
assemble an arbitrary string of characters (representing those keys on a
telephone) and send them to a modem?  I'd like to be able to programatically
control a remote process; this process uses the phone as an interface...

Any info is much appreciated.  Thanks.

Jim
Newsgroups: sci.electronics,comp.robotics
From: paul@grafted.UUCP (james caldwell)
Subject: Re: on 74ls139
Organization: GRAFTED, Central Indiana's Usenet BBS 317-881-4369
Date: Sun, 08 Nov 92 21:18:12 CST

martinez@rodan.acs.syr.edu (Kenneth Mtz. (YONIX)) writes:

> 
>  Could anyone tell me more about what this device does (?)
>  What is the pinout layout?
> 
>  Thanks,
>  Kenn.
> 

This is taken from NTE substitution index, get a copy by calling
NTE at 201-748-5089 and asking for a local distributor (may
be free from them) 
description : ic-ttl, low power schottky, dual 2 to 4 decoder
demultiplexer.
pin 1 1g enable pin 16 vcc
pin 2 select 1a pin 15 enable 2g
pin 3 select 1b pin 14 select 2a
pin 4 1 y 0     pin 13 select 2b
pin 5 1 y 1     pin 12 data output 2 y 0
pin 6 1 y 2     pin 11 data output 2 y 1
pin 7 1 y 3     pin 10 data output 2 y 2
pin 8 ground    pin 09 data output 2 y 3

If you need more infor (data sheet) you will need to ask a 
manufacturer for a data sheet, just about all make these logic
chips. They are a staple of their sales. texas instrument and motorola.
To get single units. Nte is a good choice. 
Also in any issue of Radio Electronic you can find lots of companies 
selling these for really cheap prices (under 1.00) but they may
have a min charge. Nte may provide a data sheet, ask them.

--
james caldwell
The Grafted Branch BBS
317-881-4369
internet: paul@grafted.UUCP
uucp: ..!uunet!grafted.UUCP!paul
 = = Grafted Branch BBS (317) 889-6997 2 Gig on-line = =
From: asmap@acad2.alaska.edu
Newsgroups: sci.electronics
Subject: voice chips
Date: 7 Nov 92 03:02:02 GMT
Article-I.D.: acad2.1992Nov6.230202.1
Organization: University of Alaska

Is there a source for voice recognition chips?
Newsgroups: sci.electronics
From: troyer@finmark.nynexst.com (Tom Royer)
Subject: Can anyone help me with this...
Organization: /u/troyer/.organization
Distribution: sci
Posting-Front-End: GNU Emacs 18.55.2 of Tue Mar 20 1990 on oberon (berkeley-unix)
Date: 10 Nov 92 14:05:01

Hello,

   I am trying to design a development system for the Vectrex game machine.
This is basically an eprom emulator of sorts.  Here is an excerpt from a
message I posted to rec.games.vectrex:

>    I'm still trying to get an Amiga<->Vectrex interface running.  It's
> based on Jeff Lavin's dual-port RAM development schematic.  After much
> frustration, I did this as an isolation test: I have build eprom and
> multi-game carts, so I am confident that my pinout knowledge is correct.
> I hacked a cart by removing the rom and adding a short ribbon cable with
> a 34-pin header on the other end.  On a wire-wrap board I connected the
> header-socket to an eprom socket.  Now, if I power the eprom from the
> vectrex, the vectrex will run the eprom.  From this I can conclude that
> the hacked cart/ribbon assembly is okay (the ribbon cable is only 2-3
> inches long, BTW).  If I try to power the eprom externally, however, the
> vectrex freezes.  I have connected all the grounds together properly.  I
> also disconnect the power lines from the vectrex when I try this, so I'm
> not connecting the +5 of the vectrex to the +5 of my power supply or
> anything silly like that.  I don't understand why this is not working.
> The vectrex just seems to refuse signals powered from an external
> source.

The cartridge port of the Vectrex basically has the data and address lines
that go directly to a 68A09 inside.  The eprom I used was a 27C64.  The
interface I'm designing will have 13 or so chips on it including a 32K sram.
I doubt I can power the entire thing off of the Vectrex console - this is why
I want to use an external power supply.

I'm not sure if I've included enough info here, but if anyone has any clues,
this soldering-iron-wielding-software-engineer would greatly appreciate it.

                                         -Tom Royer
                                          troyer@nynexst.com
Newsgroups: sci.electronics
From: kharstin@MtHolyoke.edu (Ken Harstine)
Subject: Adding a Second Phone Line
Organization: Mount Holyoke College
X-Newsreader: Tin 1.1 PL5
Date: Thu, 5 Nov 1992 20:33:30 GMT


I have recently had a second line added at my house.  

As you may know your existing house phone line has four wires in it.  Only
the red and green wires are used.  This means that if you connect your
existing yellow and black wires of your house wiring to the red and green
wires of your new service, you can instantly access the second phone line
anywhere in your house.  Just purchase a two line wall socket and replace
the existing socket where you need the second line.  Wire the red and
green of your house wiring to the red and green of the first socket.  Wire
the yellow and black of the house wiring to the red and green of the
second socket.  

By the way 2 line panasonic phones assume that the second line is on the
yellow and black wires, and so will work with existing single line sockets
for two line operation.
From: kolstad@cae.wisc.edu (Joel Kolstad)
Newsgroups: sci.electronics
Subject: Restrictions on 46/49MHz band?
Date: 5 Nov 92 18:38:10 GMT
Distribution: usa
Organization: U of Wisconsin-Madison College of Engineering

Hi,

I'm just curious... does anyone out there know the bandwidth limitations
on the baby monitor/cordless phone/RC car/etc. non-lincensed 46 and 49MHz
radio bands?

I believe I've heard that the power output is limited to producing an
E-field of 10000uV/m at a distance of one meter from the transmitting
antennta (correct me if I'm wrong).  But what is the frequency range
of the "49MHz band?"  I would assume that I can't start modulating my
49MHz carrier at 1Mhz, for instance... :-)

						---Joel Kolstad
						kolstad@cae.wisc.edu
Newsgroups: sci.electronics
From: kilian@cray.com (Alan Kilian)
Subject: Re: HV capacitors
Organization: Cray Research, Inc.
Date: 13 Nov 92 10:14:54 CST


Digi-Key 1-800-344-4539 Catalog #926 Page 155
68 Microfarad Aluminum electrolytic 400 Volt  #P6432 $2.83

Mouser 1-800-43-MOUSER Catalog #572 Page 124
22 Microfarad Aluminum electrolytic 450 Volt (500 Volt surge) #140-XLR450V22
$1.62

                       -Alan Kilian
-- 
 -Alan Kilian           kilian@cray.com 612.683.5499 (Work) 612.721.3990 (Home)
  Cray Research, Inc.   655 F Lone Oak Drive, Eagan  MN, 55121 
                        "It's based on actual math". -Dilbert
Xref: sparky sci.electronics:18864 comp.robotics:2318
From: harrison@cs.ubc.ca (James Harrison)
Newsgroups: sci.electronics,comp.robotics
Subject: `Passive' tracking of participants in a free space
Date: 13 Nov 1992 14:16:56 -0800
Organization: Computer Science, University of B.C., Vancouver, B.C., Canada
Distribution: world
NNTP-Posting-Host: weiss.cs.ubc.ca

We are designing an interactive-participant oriented exhibit that will
present the illusion of an audio and visual space to a participant.

To present these illusions we will be using spatially distributed
audio and visual sources (speakers and monitors) whose position,
orientation, etc will be well known and defined.

Knowing the position of the participant we will drive the audio and
visual sources to present the illusion of objects (invisible) through
the audio channels and the illusion of windows into a virtual-world
with the monitors.

The problem is in aquiring and tracking the position of the
participant.  We would eventually like to move to a system which did
not require the use of a active source carried by the participant.  A
passive reflector would be acceptable if it's cost was low enough, as
we may want to give the objects away as souvenirs.

The resolution of the tracker should be below 10 centimeters, and have
an update rate of at least 10/sec.  The system should be robust in the
presence of acoustically hard environments (echos or noise).  Be
useful in a large room (15m by 15m  by 3m at least).  Not require
extensive installation or calibration (beyond that which we will have
to do for the audio and visual sources).  And not require high
computational costs or special hardware (cheap, uniform, replaceable).

We're open to solutions using passive or active means, but we'd like
to limit the cost of the hardware/devices that the participant might
walk out of the door with.

I know that it seems like we're asking for a lot.  But we're looking
for suggestions and solutions that might require refinement.

If you have any suggestions, we'd appreciate hearing them.

Thanks in advance.

James Harrison

-- 
-------------------------------------------------------------------------------
James Harrison@cs.ubc.ca           `RPCing as fast as the network will let me.'
Newsgroups: sci.electronics
From: castellano_joe@Tandem.com (JoeCastellano)
Subject: Color TV; Wrong Colors
Organization: Tandem
Distribution: usa
Date: Tue, 10 Nov 1992 22:10:57 GMT


               Color Television Wrong Colors

Looking for some help here. 
I have a Sony 26 inch color television that was built in 1985.
The problem I have is that it now generates the wrong colors.
By the way the wrong colors are stable. 
I hooked up the output of a NTSC color bar generator to it and
 this is what I get on the screen;
================================================================
                   Should Be         Is
================================================================
                     white           white
                     yellow          blue
                     cyan            yellow
                     green           brown
                     magenta         cyan
                     red             blue
                     blue            green
                     black           black
=================================================================
I have tried adjusting the Color and Hue controls, they have
an effect but still can not get the colors correct.
 Seems like  most of the color processing is done in a single IC
and the inputs to it appear to be normal, the outputs do not.
Picture tube inputs look correct in that when it is generating
one of the colors the appropriate gun is turned on. If the IC
that does the color was not so expensive ($50) from Sony I would
just replace it if I was sure it was the problem !!
So the question I have, are there any other parts of the chroma
 system that could cause this to happen such as the Comb filter or
Luminance circuits ??

              Thanks in Advance;

						Joe 
                    Phone: 408-285-4221	


Newsgroups: sci.electronics
From: doherty@melpar (Kevin Doherty)
Subject: Re: Clock signal generator
Organization: E-Systems, Melpar Division
Date: Fri, 13 Nov 1992 14:43:01 GMT


  I think you're looking for a phase locked loop circuit; that much I can
figure out.  Unfortunately, I'm the wrong person to ask re: PLL specifics.
Good luck.
From: mpaul@unlinfo.unl.edu (marxhausen paul)
Newsgroups: sci.electronics
Subject: Re: HEX2ASM and ASM2HEX converters
Date: 9 Nov 1992 19:39:39 GMT
Organization: University of Nebraska--Lincoln	
Distribution: sci
NNTP-Posting-Host: unlinfo.unl.edu

kingpin@mole.gnu.ai.mit.edu (Joe Smooth) writes:

>I asked this a little while back, but does anyone know if there is
>a program or programs available that will convert Intel HEX (8086) format
>into .ASM format and vice-versa? I need this to edit programs burned in 
>EPROMs.. Any help would be appreciated..


Well, I'd suggest finding something that will convert hex to binary first,
then pull it into an assembler/disassembler package like Isaacson's A86/D86
package, where you can make changes at will.  (This item is called, I think,
"A86V322.ZIP" and "D86V322.ZIP" in it's latest incarnation on BBS systems
and archives all over the place, and it's very powerful software.)  I 
don't think you'll find hex-to-80x86-assembler-source and back software,
but bin-to-hex and hex-to-bin shouldn't be hard to locate.

--
paul marxhausen .... ....... ............. ............ ............ .......... 
 .. . .  . . . university of nebraska - lincoln .  . . .. . .  .. . . . . . . .
 .     .    .  .   .     .   .  .    .   .  .   .    .   .  grace .   .    .  . 
   .         .       .      .        .        .      .        .   happens .
From: mruddick@joule.elee.calpoly.edu (Michael Ruddick)
Newsgroups: sci.electronics
Subject: Tube primer?
Date: 6 Nov 92 23:48:42 GMT
Organization: California Polytechnic State University, San Luis Obispo

Does anyone have any good references for a book that would serve as a primer
about how tubes work, and especially their application in both preamp
and power-amp sections of musical instrument amps?
Newsgroups: sci.electronics
From: abond@rvgs.vak12ed.edu (Andrew H. Bond)
Subject: Re: tv transmitter
Organization: Virginia's Public Education Network (Roanoke)
Date: Sun, 08 Nov 92 06:52:23 GMT

	Check out the Amatuer Radio Handbook. It has a section
that describes a circuit that does exactly whst you want. I
never actually built it, but it seemed pretty straightforward.
-- 
andrew h bond, 	rvgs
From: sdmw91tw@ap21.rz.tu-harburg.de (Thorsten Wollweber)
Newsgroups: sci.electronics
Subject: EPROMs (again)
Date: 10 Nov 92 14:57:53 GMT
Organization: none
Originator: sdmw91tw@ap21.rz.tu-harburg.de

Again a little question regarding EPROMs:

Does a list (more or less complete) of the manufacturer and device codes,
that can be read out of EPROMs, exist?

If so, where can I get it?


   _________________________________________
  |                                         |
  |   So long and Thanks for all the Fish,  |
  |                                         |
  |      wollweber@tu-harburg.dbp.de        |
  |_________________________________________|
From: aslt@acad2.alaska.edu
Newsgroups: sci.electronics
Subject: Software Toolworks C for Z80?
Date: 13 Nov 92 03:08:07 GMT
Article-I.D.: acad2.1992Nov12.230807.1
Organization: University of Alaska

Hi,

Some months ago there was a question about C compilers for Z-80s.  The replies 
suggested small-C, Aztec Manx, and Montezuma.  I got to thinking that there
was another, and it finally came to me...  Didn't Software Toolworks 
(Walt somebody's company?) put out a C compiler for CPM as well?  
I seem to recall it because I ran across it in connection with the 64180 
'lunchbox' computer that Ciarcia put together in the (mid?) 80's for Byte.

Does this ring a bell?  Am I getting senile?  Is it still available?

Thanks in advance.  E-mail replies welcome.

Lee
From: t923335@minyos.xx.rmit.oz.au (IronEagle)
Newsgroups: sci.electronics
Subject: Thanks (Re was: VAX 11/750 Info Needed)
Date: 12 Nov 92 03:02:58 GMT
Organization: RMIT Computer Centre
NNTP-Posting-Host: minyos.xx.rmit.oz.au


I would like to thank all the people who responded to my request for
infomation on the 11/750, I have decided against purchashing this
machine for the following reasons:

   1)  Lack of 'power'
   2)  Power consumption
   3)  Cooling needs
   4)  Floorspace needs
    
 Once again, I thank everyone for their help, and knowledge.

 Damien Beeby

-- 
 ############################################################
 ##  Never assume the obvious, as it is rarely the truth!  ##
 ##t923335@minyos.xx.rmit.oz.au Iron@Eagle.aero.rmit.edu.au##
 ############################################################
From: garyf@wang.com (Gary Field)
Newsgroups: sci.electronics
Subject: Re: Very annoying Humm on home stereo
Date: 11 Nov 92 16:01:42 GMT
Organization: Wang Labs, Lowell MA, USA

ebd0@ns1.cc.lehigh.edu (EDWARD BAYKAR DERVISHIAN) writes:

>I have a REALLY old SCOTT receiver. It works absolutely fine except for one
>very annoying problem. It has a constant hum to it. Even when volume is off,
>it hums through the speakers. If I shut off the speakers, there's no noise
>(obviously). What can I do to get rid of this hum if anything?

Most likely your power supply electrolytic filter capacitors have dried up.
These can sometimes be difficult to find exact replacements for. It is
common for them to have multiple sections with different values in each
section. Usually, old equipment has enough empty space in it to stuff in
two or three individual caps in place of the original one.
If it were me, I'd buy a new stereo, but I know how some audiophiles get
attached to some of that old Scott stuff. :-)
Gary

-- 

/*-------------------------------------------------------------------------
   Gary A. Field - WA1GRC, Wang Labs M/S 019-72B, 1 Industrial Ave      
   Lowell, MA 01851-5161,  (508) 967-2514, email: garyf@wiis.wang.com
-----------  Anything not worth doing, is not worth doing well. -----------*/
From: curt@oasys.dt.navy.mil (Curt Welch)
Newsgroups: sci.electronics
Subject: Re: Software for touchtone generation; will it work?
Date: 10 Nov 92 18:51:45 GMT
Reply-To: curt@oasys.dt.navy.mil (Curt Welch)
Organization: Carderock Division, NSWC, Bethesda, MD

In sci.electronics, FELSON_ADJ@CCSUA.CTSTATEU.EDU writes:
>Can a squarewave output be used to reliable generate
>touch tones?  I'm planning on writing some machine code
>software for an HP48 calculator that would do the following:
>  scan two sine wave tables ( or use two pointers into a single table )
>  add the two together, and turn the speaker on whenever the sine
>  is positive.
>
>This would be basically a cliped version of the dual done MTMF signal.
>Anyone know if this will be too distorted for the phone company to accept?

I don't know, but I would guess that it would be too un-reliable to be
useable.  How fast can you turn the speaker output on and off?  If you
can do it fast enough, then you can try to use pulse density modulation
to get better results.  For each sine wave value, turn the speaker on
and off multiple times.  The total amount of on to off time should be
proportional to the value you are trying to produce.

Or here's an algorithm you might try.  I just though it up, so I have
no idea if it will work.  As you generate each on/off output, keep a
running sum of the output value.  Add 1 to the sum if the speaker is
"on" and subtract 1 if the speaker is off.  Also keep a running sum of
the desired sine wave value.  Decide which value to output next by
comparing the output sum to the desired sine wave sum.  If the output
is greater than the desired sum, then turn the speaker off, if the sum
is less than the desired value, then turn the speaker on.

The value you add to the speaker sum (1 in the above example) should be
larger than (or equal to) the maximum sine wave value.  So if the sine
wave sum is sin(f1) + sin(f2), then divide it by two or add and
subtract 2 from the output sum instead of 1.

This I think will give you better results than the on-if-positive off-
if-negative algorithm.  It makes the area under the square wave curve
approximate the area under the desired sine wave curve.

The faster you can turn the speaker on and off the better it will work.
If you can do it > 20K I would guess that you would get pretty good
results.

This is the basic technique used in 1 bit D to A converters.

Curt Welch
Newsgroups: sci.electronics