HDTenEightyP/NetNews huggingface dataset:
From: Jason.Goga@mailbox.bison.mb.ca (Jason Goga)
Newsgroups: sci.electronics
Subject: MC68HC16EVB project question
Date: 30 Sep 92  23:52:39 CST

 > From: martin@space.ualberta.ca (Martin Connors)
 > Path: inqmind!sys6626!bison!ccu.um
 > anitoba.ca!access.usask.ca!kakwa.ucs.ualberta.ca!news
 > Newsgroups: sci.electronics
 > Subject: MC68HC16EVB project question
 > Organization: University Of Alberta, Edmonton Canada
 > Reply-To: martin@space.ualberta.ca (Martin Connors)
 > Message-ID: <1992Sep28.204338.1580@kakwa.ucs.ualberta.ca>
 > Date: Mon, 28 Sep 1992 20:43:38 GMT

 > I just got my HC16 kit which as has been posted here before, looks lit a
 >
 > lot for $200. Due to extremely late delivery, Motorola has extended the
 >
 > deadline for completion of the project and refund of $68.16 until Oct.
 > 3.
 > That will have given me a total of only two weeks to go from a box and a
 >
 > stack of manuals to six working programs. I have done 3 so far but the 3
 >
 > to go look much more daunting and I have been stuck on one of them for
 > several days. Given these circumstances and the lack of a Motorola rep
 > here in the vast subarctic wastes, I don't think it would be cheating to
 >
 > ask someone to post or to e-mail to me solved or nearly solved listings
 >
 > for
 > PEAK.ASM, 1K_FILTER.ASM and 5BAND.ASM.

 > Thanks...Martin Connors, Edmonton, Canada

You really want that Mac don't you? :-)

Anyhow what do you think of it so far? I wanted to order one, however money ran out, also the people here in Wpg don't seem to be aware that such a thing exists.

For example how hard would it be to do an interrupt driven software-emulated serial port with 4x RX sampling at 9600 baud (asyncronous NRZ) and the corresponding TX routine? I'm trying to break the $1 / port price limit and was thinking a DSP might just do it. What do you think?

Best wishes with your contest!

-Jason

---
 * Origin: C.A. - FrontDoor (1:348/207)
Newsgroups: sci.electronics
From: tim@nebula.key.amdahl.com (Tim Nicholls)
Newsgroups: sci.electronics
Subject: Wanted : Source code for Heathkits Hero Jr. robot
Date: 29 Sep 92 15:23:39 GMT
Reply-To: tim@nebula.key.amdahl.com
Organization: Amdahl Corp


I am trying to locate the source code for the Heathkit Hero Jr. robot.
 
I built this kit back in 1985 and it basically has been siting around since.
My kids have become interested in working with the robot and I now find that 
I have a need for the source code. Heathkit no longer supports or has the
source code. 


Does anyone have the source code listing available?
The existing eprom version is 1.4 


Thanks 
Tim Nicholls 
tim@nebula.key.amdahl.com (510) 623-2104
From: sef@drutx.ATT.COM (Scott E. Farleigh)
Newsgroups: sci.electronics
Subject: Re: Any reason for GND around perimeter of PC Board?
Date: 5 Oct 92 13:38:47 GMT
Organization: AT&T, Denver, CO

In article <jeremym.718096662@sfu.ca>, jeremym@fraser.sfu.ca (Jeremy Thomas McDonald) writes:
> I have looked at a some examples PC boards and have noticed that some
> have a thick ground trace around the perimeter of the board.  Any
> reason for this?

If it is not for ground distribution, i.e. there is as separate
ground bus/plane, then it is probably for Electro-Static Discharge
(ESD). 

Scott Farleigh
AT&T Dingaling Labs
Denver
From: Jason.Goga@mailbox.bison.mb.ca (Jason Goga)
Newsgroups: sci.electronics
Subject: Help! Electronic voice changer wanted!
Date: 01 Oct 92  16:27:59 CST

 > From: <BL6OCHMW@MIAMIU.BITNET>
 > Path: inqmind!sys6626!bison!ccu.um
 > anitoba.ca!access.usask.ca!kakwa.ucs.ualberta.ca!unixg.ubc.ca!ubc-
 > cs!destroyer!uunet!cis.ohio-state.edu!pacific.mps.ohio-
 > state.edu!ohstpy!miavx1!miamiu!bl6ochmw
 > Newsgroups: sci.electronics
 > Subject: Help! Electronic voice changer wanted!
 > Organization: Miami University - Academic Computer Service
 > Message-ID: <92271.191336BL6OCHMW@MIAMIU.BITNET>
 > Date: Sunday, 27 Sep 1992 19:13:36 EDT

 > I am looking for the schematics/a kit/pre-fabricated device which can
 > attach

 > or easily be attached to a telephone in order to change all of the

 > characteristics of a person's voice.  The more flexible the electronics,

 > the better.

 > bl6ochmw@miamiu.acs.muohio.edu

Hmm, now that's an odd request!

How about adding a constant to the frequency of said voice (except at 0), and
exponentially amplifying the result. That would pretty much throw anybody off I'de think. How to do it, ppt, that I don't know. I take it that just putting a hanky over the reciever won't cut it?

-Jason

---
 * Origin: C.A. - FrontDoor (1:348/207)
From: Michael.Covington@mailbox.bison.mb.ca (Michael Covington)
Newsgroups: sci.electronics
Subject: Grounded soldering iron tip
Date: 5 Oct 92 09:43:25 GMT

Organization: AI Program, University of Georgia, Athens

How important is it to have the tip of a soldering iron be grounded
(as opposed to simply disconnected from everything)?

I use a small grounded-tip iron most of the time, but I have a larger
one, occasionally used for desoldering, which is not grounded-tip.
Should it be?  I can probably modify it by putting on a new line cord.

-- 
:- Michael A. Covington     internet mcovingt@uga.cc.uga.edu 
:- Artificial Intelligence Programs       phone 706 542-0359
:- The University of Georgia                fax 706 542-0349
:- Athens, Georgia 30602 U.S.A.          amateur radio N4TMI

 * Origin: The Electronic Mailbox (1:348/7.0)
From: Jason.Goga@mailbox.bison.mb.ca (Jason Goga)
Newsgroups: sci.electronics
Subject: Multimeters
Date: 01 Oct 92  00:00:52 CST

 > Subject: Re: Multimeters
 > Organization: Joint Center for Radiation Therapy
 > Reply-To: frank@rover.uchicago.edu
 > Message-ID: <29SEP199208160627@rover.uchicago.edu>
 > Date: 29 Sep 92 14:16:00 GMT

    We (read that I,) did a similar thing to a Fluke 4-1/2 digit dmm. It
    was reading the reservoir voltage on a high voltage thyratron when we
    cranked up the main HV. Only got RF to the fluke but it went south
    for the winter. Again cost about $30 to repair.

Please forgive my inherent ignorance, but I've been stagnating in worldy knowledge for the past 2 years (couldn't get into university, nor a job that trains on the job) as a mere Tech. a thyratron is, basically the tube equivalent of an SCR no? Just curious.

-Jason

---
 * Origin: C.A. - FrontDoor (1:348/207)
Newsgroups: sci.electronics
From: dale@ldgo.columbia.edu (dale chayes)
Subject: (anti)static bags
Keywords: esd static control bags
Organization: Lamont-Doherty Geological Observatory
Date: Tue, 6 Oct 1992 20:12:29 GMT

	I'm looking for the source of a particular kind (style) of
anti-static (esd) protection "bags".  The type I have in mind are
closed by a velcro tab after folding in the four "flaps". This wrapper
includes not only ESD protection, but "bubble pack" mechanical
protection as well. The Velcro (more properly hook-and-loop) closure
makes them substantially easier to use.

	 The only one I've actually seen was the one that came wrapped
around an interface adapter for an HP-54601A scope. The logo "SECO" is
imprinted on the bag, but I have not yet been able to identify the
manufacturer/vendor.


Thanks in advance for any clues,
-Dale


-- 
Dale Chayes Lamont-Doherty Geological Observatory of Columbia University
Route 9W, Palisades, N.Y.  10964	dale@lamont.ldgo.columbia.edu
voice:	(914) 359-2900 extension 434	fax: (914) 359-6940
From: sehari@iastate.edu (Babak Sehari)
Subject: Re: Help my project SPEAK...
Originator: sehari@vincent1.iastate.edu
Organization: Iowa State University of Science and Technology, Ames, Iowa.
Date: Mon, 28 Sep 1992 05:51:54 GMT

In <YekpR3200UhWE4tIth@andrew.cmu.edu> Matthew Keith Albright <ma2b+@andrew.cmu.edu> writes:

>Okay, I would like a project that I am workng on to be able to speak. 
>Like maybe 10 - 20 different 3-4 second messages (In perhaps three
>languages).  What is the easiest (cheapest) way to do this?  My ideas so
>far: 

>1) Get one of those phonic-based chips that can say anything, all you
>have to do is arrange the individual phonics.  Good: flexibility  Bad:
>sound quality.

>2) Pre-record the messages and somehow get them into EPROM, using a
>vocoder or something like that.  Better sound quality but less
>flexibility and a lot of memory is needed to store the messages.

>The method chosen will have to be able to be interfaced to a
>microcontroller.  So are either of these ideas valid, or is there a
>better way to do this?  Any ideas are welcome.  FYI, I am leaning toward
>idea #2.

>Thanks in advance, and please reply by email.

>matt
>ma2b+@andrew.cmu.edu

There is a book called "Chip Talk:  Projects In Speech Synthesis", by
D.  Prochnow; Pub. TAB ISBN: 0-8306-1912-7
I guess it has many suggestions you might like to incorporate in your
project.  Also, filter your talk to <3KHz, then use PCM for your second
method. This way you use 16 levels or 4 bits per sample and 2*4*3K=3KByte
per second.  I do not think you need more then 10 minute worth of massage,
so you'll need only 10*60*3=1800 or less than 2Mbyte memory.  You can get
it as two 9*1M SIM cost only $60.00.  10 minutes is a generous massage time,
too.

                       With highest regards,
                            Babak   Sehari.


From: myers@hpfcso.FC.HP.COM (Bob Myers)
Date: Mon, 28 Sep 1992 16:50:12 GMT
Subject: Re: Continuous Power
Organization: Hewlett-Packard, Fort Collins, CO, USA
Newsgroups: sci.electronics

> >Also, in a less important way, the CRT is one of
> >very few electronic components that performs more poorly from constant use.
> 
> 	With one minor caveat to the above:
> 
> 	1/ Many good terminals, (such as the one I am using now,) have a
> 	   screen saver feature that blanks the screen after some time without
> 	   activity. This greatly improves the longevity of the phosphor.

Unfortunately, the phosphor is only part of the CRT aging problem; the other
part is the decrease in cathode emissivity with age, which is NOT affected
by the typical "screen saver".  Actually, the cathode life can actually
be degraded by the "blank screen" version of screen saver; yes, the tube is
cutoff, but the cathode is still maintained above its critical temperature
by the still-on heater.  Since it's biased negative, it emits, but since the
tube is cutoff, the electrons hang around the cathode - and the bombardment
of the cathode surface by the occasional electrode "wears it out" that much
faster.  The best screen saver would occasionally display SOMETHING every so
often, to let the cathode "clean itself."  

Best of all would be some way to reduce the heater voltage when the display
is in "screen saver" mode, so that the cathode would be "too cool to age",
but there's no good way to do that yet.  Until we get this feature from the
monitor folks, the best idea is to turn the display OFF when you're going
to leave it idle for a long period - definitely when you're going home for the
night.  The CRT is the shortest-lived part in the display by a wide margin,
on average, so the slight degradation caused to everything else by the once-
a-day thermal shock is worth it in tube life.


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: holderied@urz.unibas.ch
Newsgroups: sci.electronics
Subject: Current-sources(need help)
Date: 6 Oct 92 15:40:08 MET
Organization: University of Basel, Switzerland

I am currently debugging a circuit which contains
the following current-sources:

CIL256 , 1N5290

Can anybody tell me, what their rated currents are,
and who produces them?

thanks                george

Newsgroups: sci.electronics
From: derbyc@tplrd.tpl.oz.au (Derby Chang)
Subject: Re: VCR rewind and tape head question
Organization: Telectronics Pacing Systems
Date: Mon, 28 Sep 1992 03:16:22 GMT


In article <1992Sep24.031152.20380@nmsu.edu> Joseph Good writes:

> My room-mate and I are arguing over a very silly matter here.
> He refuses to let anybody rewind on his VCR because he insists
> that the tape head never retracts from the tape.  Because of this,
> when you are rewinding, the tape is wearing down the head all the time.

This sounds like a marketing gimmick used by people making dedicated tape
rewinders.  Reminds me of a Woody joke on `Cheers', where he buys through
mail order, a VCR that doesn't play tapes.

> But, I insist that the tape DOES retract from the tape surface when not 
> in play (i.e. the wait and noise when play is activated), and that
> no company would market a VCR that allows itself to get head wear that
> easily.  Plus, the VCR head is spinning anyway during play at very high
> speeds, so tape friction shouldn't cause that much wear at all.
> The noise when you first put a tape into the player is in fact the tape
> being moved so that the head can have access to it, but not yet in 
> contact with the head.

> Who is correct??

The point worrying engineers was not so much tape-head wear but stress on
the tape.  The more angles a tape has to pass through on the tape path, the
more likely something nasty is going to happen, like
VCR-eats-favourite-Twin-Peaks-episode.

Because of the M-load tape path used by VHS, rewinding or fast
forwarding with the tape engaged placed too much stress on the tape, so it is
generally retracted partially or fully.  The tape counter does not need to be
engaged to the tape, it can work off the tape spool, although I guess this
might differ between makes.

BTW, the very much superior Betamax system uses the much gentler U-load, so
fast forwarding or rewind can take place with the tape in contact with the
head, with no adverse tape or head wear.  Also it has the benefit of the
picture playing after << or >> almost immediately.

+------------------------------------------------------------------------+
|  Derby Chang			|"Cathy, I said, I have no sympathy,     |
|  Telectronics Pacing Systems	| Look up `masochism' in the dictionary" |
|  Syndey, Australia            |					 |
|  (Tel): 0011-61-2-413-6940    |               Flanagan & Richardson    |
|  derbyc@tplrd.tpl.OZ.AU	|		                         |
|                               |                                        |
+------------------------------------------------------------------------+                 
Newsgroups: sci.electronics
From: feg@cbnewsb.cb.att.com (forrest.e.gehrke)
Subject: Re: 25 ohm coax cable
Keywords: coax cable
Organization: AT&T
Date: Tue, 6 Oct 1992 18:24:37 GMT

In article <1992Oct5.151512.29320@athena.cs.uga.edu> mcovingt@aisun3.ai.uga.edu (Michael Covington) writes:
>In article <1992Oct5.142505.23001@dxcern.cern.ch> dhina@dxcern.cern.ch (Mourad Dhina) writes:
>>Hello,
>>i am trying to realize a circuit i found in an electronics magazine.
>>one of the components it uses is a semi-rigid coax cable of
>>25 ohms impedance. this is the first time i hear of this (i only
>>knew 50, 75 and 93 ohms cables, which are standard). anybody
>>knows where to find this?
>>Mourad
>
>Two 50-ohm cables in parallel?
>

Those aren't the only characteristic impedances available, however
two 50 ohm cables in parallel will accomplish it, with the proviso
they are identical in length.  The center leads at both ends are
paralleled; similarly the sheaths.  I have no idea why your circuit
would require semi-rigid cable except you must be careful to avoid
any sharp kinks and it would be a good idea to use coax with a
high percentage of sheath coverage.

Forrest Gehrke k2bt feg@dodger.att.com

Newsgroups: sci.electronics
From: jeremym@fraser.sfu.ca (Jeremy Thomas McDonald)
Subject: Any reason for GND around perimeter of PC Board?
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Sat, 3 Oct 1992 07:17:42 GMT

I have looked at a some examples PC boards and have noticed that some
have a thick ground trace around the perimeter of the board.  Any
reason for this?

Newsgroups: sci.electronics
From: stettbac@isibee7 (Juerg Stettbacher)
Subject: Re: GAL tristate question
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
X-Newsreader: TIN [version 1.1 PL6]
Date: Thu, 1 Oct 1992 09:56:59 GMT

John Haddy (johnh@macadam.mpce.mq.edu.au) wrote:
: 
: We've relatively recently started using GAL's from Lattice in our designs. For,
: the first time, our latest project had cause to use the tri-state feature of
: 16V8's and 22V10's (i.e. having a product term control the .OE line).
: 
: We use CUPL to compile the source to a JEDEC file, and a Logical Devices ALLPRO
: to program them.
: 
: The problem is: while the pins without .OE control function perfectly, those
: which we do wish to tri-state don't seem to. 
: 
: In one case, an output should go Hi-Z when a switched input is active. However,
: the line stays permanently high, and cannot be pulled low with a resistor to
: ground. 

Hi John

The GAL 16V8 and 20V8 have output logic macrocells (OLMC). These cells can be
configured in different ways using the flags SYN, AC0, AC1(n):

   - SYN = 1, AC0 = 1, AC1 = 1: Combinational output.
     OE- not in use. Output driver controlled by a product term (from logic 
     matrix).
   - SYN = 1, AC0 = 1, AC1 = 0: Cell disabled.
   - SYN = 0, AC0 = 1, AC1 = 1: Combinational output in registered mode.
     OE- not in use for this cell. Output driver controlled by product term.
   - SYN = 0, AC0 = 1, AC1 = 0: Registered mode.
     Output driver controlled by OE- pin.
   - SYN = 1, AC0 = 0, AC1 = 0: Combinational output.
     Output driver allways active.
   - SYN = 1, AC0 = 0, AC1 = 1: Input pin.
     Output driver allways turned off.
   - SYN = 0, AC0 = 0, AC1 = 1: Input pin.
     Output driver allways turned off.
   - SYN = 0, AC0 = 0, AC1 = 0: Combinational output.
     Output driver allways turned on.

In fact there are some more differenced between the operation modes as 
described above (the pin feedback as an example). Furthermore the 8 OLMC
are not all identical. Check a data book about this.

How to program the SYN, AC0 and AC1(n) flags? Check the description of
your programming tool. (Sorry I use a different one.)
As far as I know, most tools use extentions within the pin definition
section of your source code.


Good luck
juerg at ethz switzerlan
From: carmijo@hpnmdla.sr.hp.com (Chris Armijo)
Newsgroups: sci.electronics
Subject: Re: Spectrum anaylsers
Date: 5 Oct 92 16:31:44 GMT
Organization: Hewlett-Packard, Santa Rosa, CA

In sci.electronics, dpm@latcs2.lat.oz.au (Odysseus) writes:


       Can anyone tell me (or, preferably, point me in the direction of a
    book on) how spectrum analysers work? I can see a digital analyser
    performing a fft on some sampled data and displaying the spectrum from
    this info, but the fastest ADC I know of runs at 100MS/s, giving a maximum
    frequency of 50 MHz. The analysers we have here can display 50 GHz, so,
    unless there's some kind of input frequency reduction (ie rooting circuit)
    they can't use this kind of thing. Performing fft's in real time is not
    really the problem - I know of several frequency domain processors. Is an
    analogue Fourier transform possible?

Spectrum analyzers work the same way that virtually all radio receivers do.
The input signal is "heterodyned".  What this means is that the input 
signal is sent into one port of a mixer (RF).  Another signal, slightly offset
from the input signal is put into the other port of the mixer (LO).  The
mixer acts as a multiplier.  If you go through the math you will find that
the output of the mixer will be two signals: one signal at the *sum* of
the two input frequencies (RF+LO) and one signal at the *difference* of
the two input frequencies (RF-LO).  The spectrum analyzer filters the
output to choose only one of these signals.  Thus, the output of the 
mixer will be at a frequency much different than the input -- in the
case of the 50 GHz analyzer, the output frequency will be much lower.

For example, let's say the the LO signal is 49.999GHz and the input signal
is 50 GHz.  Then the mixer output will be .001 GHz = 1 MHz.  This 
1 MHz signal is then processed.  Typically in spectrum analyzers, the
processing consists of filtering, a "log amp" (an amplifier that 
takes the logarithm), and an ADC.  

This is how such a high frequency signal is processed -- it is simply
converted to a low frequency signal that we can easily handle.  Of course,
in the real world, things get much more complicated.  Spectrum analyzers
use more than one mixer and convert the signal to 2 or 3 different
frequencies.

To learn more about mixers, check out any first year course in communication
theory.

Chris
Newsgroups: sci.electronics
From: swanee@megadata.mega.oz.au (Geoff Swan)
Subject: Re: DC to AC help
Organization: Megadata P/L, North Ryde, Sydney, Aust.
Date: Thu, 1 Oct 1992 23:21:58 GMT

In article <1af8isINNo3u@darkstar.UCSC.EDU>, lance@helios.ucsc.edu (Lance Bresee) writes:
> 
> Hey, I just had a thought,
>     Take a high power mosfet and operate it as a class C amplifier
>     driven by a 60Hz oscilator.  Run the output through a tank tuned
>     to 60Hz.  The inductor in the LC circuit is the primary of a
>     step-up transformer which takes your resulting sine wave to
>     line level.
> 
>     Obviously, inductive loads on the output will effect the 
>     inductance of the Lc circuit, and cause some change in
>     frequency....I don't know how that would be dealt with.....

Welcome to the world of resonant-type switch mode power supplies. The
efficiency of a class C amplifier is not all that good (I think about
60% theoretical maximum), but the idea is along the lines of that used
in good power inverters. At 60Hz, usually thyristors are used which turn
off when the resonant voltage wave goes through zero. A tank is tuned to
the frequency desired (usually a large capacitor and many adjusting taps
on the saturable reactor). I remember working on a 10kW power inverter
like this about 10 or so years ago and we got 85-95% efficiency from it.
These days, with Mosfets, resonant mode switching PSU's are used for DC-DC
conversion (or off-line PSU's) at a switching frequency of a megahertz or so.
(I'm working on a 1MHz resonant DC-DC converter right now). The magnetics
are quite tricky - you have to make the transformer inductance negligible
when compared to the resonant inductor so that the system won't require
tuning every time a new batch of transformers is wound or the load
changes etc. Anyhow back to the lab for now ...

    Sla/n go fo/ill,
                    Risky B.
--------------------------------------------------------------------------
Geoff Swan (research & development)   _--_|\         swanee@megadata.oz.au
Megadata Pty Ltd                     /      \ 
2/37 Waterloo Rd, North Ryde,        \_.--._/               +61 2 805 0899
NSW 2113, Australia.                       v          (Fax) +61 2 887 4847

Newsgroups: sci.electronics
From: martin@space.ualberta.ca (Martin Connors)
Subject: MC68HC16EVB project question
Keywords: motorola,microcontroller
Reply-To: martin@space.ualberta.ca (Martin Connors)
Organization: University Of Alberta, Edmonton Canada
Date: Mon, 28 Sep 1992 20:43:38 GMT

I just got my HC16 kit which as has been posted here before, looks lit a  
lot for $200. Due to extremely late delivery, Motorola has extended the  
deadline for completion of the project and refund of $68.16 until Oct. 3.
That will have given me a total of only two weeks to go from a box and a  
stack of manuals to six working programs. I have done 3 so far but the 3  
to go look much more daunting and I have been stuck on one of them for  
several days. Given these circumstances and the lack of a Motorola rep  
here in the vast subarctic wastes, I don't think it would be cheating to  
ask someone to post or to e-mail to me solved or nearly solved listings  
for 
PEAK.ASM, 1K_FILTER.ASM and 5BAND.ASM.

Thanks...Martin Connors, Edmonton, Canada