HDTenEightyP/NetNews huggingface dataset:
From: jeremym@fraser.sfu.ca (Jeremy Thomas McDonald)
Subject: High-speed max. Parallel cable length???
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Thu, 7 Jan 1993 22:16:59 GMT

I am using a 74HCT244 bus driver and 74LS377 octal D-latch to transmit
roughly 1MB/second across a DIN-25 Parallel cable.  Is there a maximum
length allowed to get this transfer rate?  The computer is receiving
data and sending a few control signals back to the device (like the
!DRDY line is pulsed back to the device after every byte is fetched).
I am thinking about using a 3 foot cable.  Is this too long?  Should
I be terminating the data lines with capacitors on the device end?
I don't know anything about analog stuff, just want the digital to work.
(I know... welcome to the real world...)
Please e-mail me:

jeremym@fraser.sfu.ca - yes a lowly computer science student.

Newsgroups: sci.electronics,sci.energy,rec.autos
From: gary@ke4zv.uucp (Gary Coffman)
Subject: Re: Flywheel batteries as EV power source
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Destructive Testing Systems
Date: Sat, 9 Jan 1993 18:34:14 GMT

In article <1993Jan8.010401.6096@cis.ohio-state.edu> rubin@skiing.cis.ohio-state.edu (Daniel Rubin) writes:
>
>I think comparing expanding gases or fluff or whatever in a flywheel and 
>that of gunpowder in a gun barrel is not justified.  The gasses released
>from black powder in a gun barrel act to push an object to "mach 1" or
>whatever speed was posted earlier in ONE direction.  You cannot compare this
>to gas or whatever explaning in 3-D space.  I pile of black powder won't move
>an object placed on top of it at all or a very small amount, probably 1/100000
>the acceleration of it in a barrel.  That actally turns out to be a great
>example. In a previous post it was said that 7 grains of black powder can
>push a bullet to mach 1.  That may be true IN A GUN BARREL.  Take 1 pound of
>black powder and place it on the ground and put a bullet on top of the pile.
>Light the pile and you get a lot of fire and heat and the bullet will most
>likely not even budge, just get really hot!  I wish I could include the 
>amount of hot gasses released from a pound of black powder as compared to 
>7 grains, but I can't and the ratio between 7 grains and 1 pound should
>describe the situation well enough...

I urge you not to try this experiment at home. Blackpowder is a primary
explosive rather than a flamable solid. It can explode *unconfined*
when ignited in amounts of 1 pound or more. That explosion will be more
intense than that of a similar amount of dynamite, which will also 
explode unconfined. To dispose of blackpowder safely by burning, you
must spread it thinly along the ground in trains and ignite only one
end, allowing it to burn *slowly* with the heat rapidly conducted away
by the large mass of air to which it is exposed.

Gary
-- 
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary      
Lawrenceville, GA 30244     |                     | emory!ke4zv!gary@gatech.edu
From: at847@cleveland.Freenet.Edu (Jeff Hunsinger)
Newsgroups: sci.electronics
Subject: Home game pin-outs
Date: 11 Jan 1993 21:26:25 GMT
Organization: Case Western Reserve University, Cleveland, Ohio (USA)
NNTP-Posting-Host: hela.ins.cwru.edu


I'm looking for cartridge slot pin-outs for all popular game systems
(Nintendo, Sega, Atari, etc.) Any help is greatly appreciated!
Also, programming help (other than the Atari 2600 - I've already got
that) would be a nice bonus.

Jeff
From: cstadbg@csv.warwick.ac.uk (Mr M J Brown)
Newsgroups: sci.electronics
Subject: Re: EPROM programming info.
Date: 12 Jan 1993 12:27:34 -0000
Organization: Computing Services, University of Warwick, UK
NNTP-Posting-Host: lily.csv.warwick.ac.uk

In article <1993Jan11.165157.27506@bernina.ethz.ch> stettbac@isi.ethz.ch (Daniel Mueller) writes:
>
>You should expect different programming voltages; the optimal timing
>may also be different. But don't worry about that too much with your
>programmer. The programming may take a little longer (if puls prog.
>mode is used) but you'll get your EPROM ..
>
>Anyway, you will find all details in the data books.

I have managed to get a 2764 to retain data using a 1ms pulse time, even though the
data states 40ms minimum, 50 ms typical. I found this while testing and setting up
a DIY Eprom programmer.

How long the data retains for, I dont know, but I wouldnt have thought it would work
at that sort of speed!

=============================================================================  
     _/      _/   _/   _/  _/   _/_/_/_/   |
    _/_/  _/_/   _/   _/_/     _/          |         Michael Brown
   _/  _/  _/   _/   _/       _/_/         |
  _/      _/   _/   _/_/     _/            |   cstadbg@csv.warwick.ac.uk
 _/      _/   _/   _/  _/   _/_/_/_/  _/   |     mjb@dcs.warwick.ac.uk
                                           |    csulo@csv.warwick.ac.uk
=============================================================================
From: edhall@rand.org (Ed Hall)
Newsgroups: sci.electronics
Subject: Re: Where to mount an outside temp probe on a car?
Date: 5 Jan 93 02:26:40 GMT
Organization: RAND

In article <1993Jan4.223650.9171@phx.mcd.mot.com> schuch@phx.mcd.mot.com (John Schuch) writes:
>Excuse me but if you cool the sensor by placing it in an airstream, your
>not reading the actual temperature of the air.

Say what?  Assuming the sensor doesn't generate heat, how does moving
air past it do anything but speed up its equilibrium with the air
temperature?

>Reading a sensor cooled
>by an airstream, by itself, tells you nothing. If you measure one sensor
>in an airstream and another one nearby but shielded from the air stream,
>you can determine the speed of the airstream.

But that's only if the sensor generates heat!  Otherwise (ignoring venturi
and friction effects for the moment) the two sensors will reach exactly
the same equilibrium temperature, except the one in the airflow will do so
more rapidly, and will respond faster to changes.

>Other than that, I don't
>know why you would want to cool the sensor.

Neither do I.

>You will note that weather stations keep the thermometer in a little
>louvered box to break-up the wind. Even high-end indoor/outdoor
>thermometers include a little shell to place over the external
>sensor.

Yup.  Helps isolate the sensor from the sun and other sources of
radiant heat.  It isn't to protect it from the wind; in fact, you might
well find a circulating fan in that little louvered box to help lower
the sensor's time constant and reduce the effects of IR absorption by
the enclosure.

But back to the original subject: placement can make a difference,
especially at higher speeds, due to the venturi effect. (Air friction
is probably less of a problem at normal automotive speeds.) This could
lead to either a high or low reading, depending upon whether the air
is under local compression or rarification.

Any physics types want to estimate the magnitude of this effect?

Proximity to local heat sources (engine, pavement, tires, or surfaces
subject to solar radiation) can have an effect; air movement might well be
a good way to minimize this, however.  Shielding would be a good idea, but
the idea is to minimize IR absorption, not shield from wind.  Perhaps a
thin insulating tube, painted outside with reflective paint and oriented
/parallel/ to the airflow, with a small sensor mounted inside (such that
the airflow is obstructed by it as little as possible).

		-Ed Hall
		edhall@rand.org
Newsgroups: sci.electronics
From: snelson@cray.com (Steve Nelson)
Subject: Handshaking sequence for modems
Organization: Cray Research, Inc.
Distribution: usa
Date: 8 Jan 93 20:12:14 CST

Can anyone tell me where I can obtain detailed handshaking sequence         
protocols used during the connection sequence of two modems?  I would        
like to emulate this sequence with some special purpose hardware.             
Although I am interested in only 300 baud, I want the sequence to          
work for virtually any auto-baud detect modem that might be on the    
other side.                                                              
                                                                        
Steve Nelson
Cray Research
snelson@romulus.cray.com

Newsgroups: sci.electronics
From: boortz@sics.se (Kent Boortz)
Subject: What is the truth about capacitors?
Organization: Swedish Institute of Computer Science, Kista
Distribution: sci
Date: Thu, 7 Jan 1993 23:54:37 GMT



Could anyone explain when to use what kind of capacitor?
Do you have any tumb-rules? I thought the choice was
easy for electrolytic caps, use tantalium for low noice. 
But from an article in february 1992 in elector electronics:

	"..tantalium capacitors are not really suitable for
	processing audio signals..."

If I was to build a low noice microphone preamp:

	What kind of ~470uF cap to use in series with the 
	200/600 ohm microphone?

	What kind do I use for ~100uF decoupling in the 
	first and second stage?

	What 33pF to use between base collector?

	Where in a typical circuit does it matter if the cap
	is low distorsion and low noice. Decoupling caps relly
	kill all AC over ~20 Hz so does it matter there?

	What type of cap to use for AC connecting different
	amplifer stages? If I can choose a bipolar over a
	electrolytic (because value is both ranges) is it better?

	Is a electrolytic cap with low current leakage always
	better than one with higher leakage?

	What types of cap to use in an ordinary tone control?

	Is noice performance improved if I put a small polyester 
	cap in parallel with a large electrolytic cap. I assume
	most noice is above say 1 KHz.

	What cap to use in power circuits after a 7812 voltage
	regulator? Will the wrong type give noice or hum in 
	the preamplifer?

	Is there something else to think about if I use SMD caps?

A lot of questions but I hope you will give me some of the answers.

Thanks!

/kgb
--
Kent Boortz
boortz@sics.se
Xref: sparky sci.electronics:22103 alt.cd-rom:5481
From: dh@fncrd6.fnal.gov (don husby)
Newsgroups: sci.electronics,alt.cd-rom
Subject: Re: chip vendor databooks/sheets/applic notes
Date: 6 Jan 93 16:47:02 GMT
Organization: Fermilab
NNTP-Posting-Host: fncrd6.fnal.gov

kgdykes@thinkage.on.ca (Ken Dykes) writes:

>do any semiconductor makers have available on CD-ROM their databooks and
>application notes?

It's been tried several different times and usually fails.
Back a few years ago, there were at least two services that
offered parts databases on bulletin board services.  For various reasons, they
died.

About two years ago our library benchmarked a number of(3?) CD-ROM based
catalog services.  The one I happened to see consisted of about 20 disks
and included a cross reference database as well as scanned pages from actual 
data books.  We never got the service, I'm not sure why.  I think the price 
was ~$4000. If people want names, etc. send me email and I will try to track
them down.
Newsgroups: sci.electronics
From: qureshi@ug.cs.dal.ca (Saqib Ahmed Qureshi)
Subject: Do they make Radio Shack 276 - 017 or equiv IC's anymore?
Organization: Math, Stats & CS, Dalhousie University, Halifax, NS, Canada
Distribution: can
Date: Tue, 12 Jan 1993 03:10:00 GMT


Hi,
 Well this is what I'm looking for 
     IC - Type 709 (Radio Shack 276 - 017 or equiv.).
      ... I went to my local Radio Shack Dealer and he goes:" We don't have 
      this"...I got this project from a book written way back in 1975. I hope
      the thing is still on la shelf.

     2 megaohm (Radio Shack 271-093 or equiv) & 250,000 ohm potentiometers.
     Can't seem to find these anywhere...any suggestions?

..er I live in Dartmouth, NS..so if the place you know is outta town..tell me
anyway .. a last resort is better than nothing..but I would appreciate a local
address  or dealer name.

Please reply by e-mail.
Thanks in advance.
			      -Saqib
Organization: Queen's University at Kingston
Date: Thu, 7 Jan 1993 00:51:49 EST
From: <LEEK@QUCDN.QueensU.CA>
Newsgroups: sci.electronics
Subject: Re: PC VLSI Design package
Distribution: world
 <1ickg8INNgt0@sdl.Warren.MENTORG.COM>

In article <1ickg8INNgt0@sdl.Warren.MENTORG.COM>, garyg@warren.mentorg.com (Gary
Gendel) says:
>
>for the hobbiest, however, we have been toying with releasing a restricted
>version (no more than 500 elements) of out logic simulator, SIMIC for no
>charge.  This simulator has been claimed by many as the best gate/switch level
>simulator available anywhere.  The biggest hurdle is condensing our
>300+ user manual into a small text file.

Make money $$$ by sell the manuals... :)

>Since SIMIC elements range from simple gates to large functional blocks (RAMS,
>PLAS, etc) the 500 part limit should allow most hobby and educational designs ,
>but prevent competition with our commercial product.

Sound good.  There is just one catch...  What can people do with the
package ?  Would be nice to support Xilinx's SRAM based FPGA or Lattice's
ispLSI or similar devices.  (Can restrict to only a few chips.)  These
device can probably be programmed from parallel port.  Anything thing else
would require an expensive programmer which sort of restrict the market.

>We just need to determine if there is enough interest to warrant this effort.

Yeap.  There is always a segment of the lower end that have been
overlooked by the big companies.  EPLD are kind of small... :(

>Gary Gendel
>VP Customer Relations
>Genashor Corp
>9 Piney Woods Drive
>Belle Mead, NJ 08502
>(908) 281-0164
>

K. C. Lee
Elec. Eng. Grad. Student

Would be nice to see a Commodore Amiga version too.  :)
Newsgroups: sci.electronics
From: doug@ve7frg.ampr.org (Doug Collinge - VE7GNU)
Subject: "1-bit DAC"
Organization: G.M. Systems
Date: Wed, 6 Jan 1993 07:22:37 GMT
X-Newsreader: TIN [version 1.1 PL6]

If my CD with a "1 bit DAC" and the aid of "8 times oversampling"
can produce audio as good as an older CD with no "oversampling" and
a 16-bit DAC then can my circuit with an 8-bit DAC be replaced
with a 1-bit DAC and 4-times oversampling?

How?  What's the math behind this concept anyway?
Newsgroups: sci.electronics
From: stigvi@Lise.Unit.NO (Stig Vidar Hovland)
Subject: Re: [Q] Spice sources ?
Organization: Norwegian Institute of Technology
Date: Tue, 12 Jan 93 13:57:54 GMT

In article <1993Jan12.083010.25027@newsserver.rrzn.uni-hannover.de>, cseb@frodo.lfi.uni-hannover.de (Christian Sebeke) writes:
 > Guten Morgen Netz!
 > 

 > OTHER:
 >   The original SPICE program may be obtained directly from Berkeley.
 > I'll include an old posting from Berkeley. Due to the changes in the
 > east, the restrictions mentioned have become less.
 > 
Can anyone tell me if the C version of SPICE is available via anonymous FTP.

Stig Vidar Hovland - stigvi@lise.unit.no
From: csmith@plains.NoDak.edu (Carl Smith)
Newsgroups: sci.electronics
Subject: Re: Receiver Pre-amps
Keywords: pre-amp, intermodulation, antenna
Date: 13 Jan 93 00:57:53 GMT
Article-I.D.: ns1.C0rpCI.DE5
Organization: North Dakota Higher Education Computing Network

In article <1993Jan12.220413.8315@kodak.kodak.com> ornitz@kodak.kodak.com (Barry x24904/ER/167B-TED) writes:

>In article <1993Jan12.202208.17471@ecsvax.uncecs.edu> crisp@ecsvax.uncecs.edu 
>(Russ Crisp) writes:
>>I'm looking for a good quality low noise figure mast mounted
>>pre amp for FM broadcast band reception.

>This should be a pretty trivial design using one of the microwave monolithic
>integrated circuits such as those made by Mini-Circuit Labs or Avantec.  A
>MCL MAR-6, for example, will cost less than $3 and provide 20 dB of gain at
>100 MHz with a NF below 3 dB. It will require two (chip-style is preferred)
>coupling capacitors, a resistor, an RF choke, and a power supply to be fully
>functional as an RF amplifier.  For 75 ohm input, a 4:1 balun will be needed.

I just thought that I would add that I just picked up the Feb 93 issue
of Popular Electronics today and it has an article about building amps
with the MAR series.  "Antenna Amplifiers That You Can Build" by
Joseph J. Carr, pages 43 to 46.  Of couse, it's all (C)1992 by Popular
Electronics, so I can't reproduce the diagrams here.   :)
Xref: sparky sci.electronics:22468 sci.energy:6801 rec.autos:31545
From: drew@bnr.co.uk (Scooby Doo)
Newsgroups: sci.electronics,sci.energy,rec.autos
Subject: Re: Flywheel batteries as EV power source
Date: 12 Jan 1993 10:02:53 GMT
Organization: BNR Europe, New Southgate, London.
NNTP-Posting-Host: bnsgs211.bnr.co.uk

In article <1992Dec28.220947.19148@michael.apple.com> ems@michael.apple.com (E. Michael Smith) writes:
>In article <1hnnrdINNnna@gap.caltech.edu> carl@SOL1.GPS.CALTECH.EDU writes:
>>In article <1992Dec22.204130.18133@enterprise.rdd.lmsc.lockheed.com>, () writes:
>wrap the flywheel in a 200 lb water jacket and still be lighter than
>a lead/acid battery pack, it might still be 'reasonable' ...
>
>Now, getting all that KE dumped evenly into the water jacket could be
>quite a trick ;-) and will be left as an excersize for the reader ;-) ;-)
>

	And when your fly wheel disintegrates, you'll have plenty of
hot water for coffee. Saves you sticking a dinky little immersion heater
in the cigarette lighter! :-)

-- 

Pretty damn silly place to leave a signature...

Newsgroups: sci.electronics
From: doug@ve7frg.ampr.org (Doug Collinge - VE7GNU)
Subject: Re: Microwave Oven Plasma Etcher?
Organization: G.M. Systems
Date: Fri, 8 Jan 1993 05:16:52 GMT
X-Newsreader: TIN [version 1.1 PL6]

Why don't you waste some of the power by boiling some water
away or something like that?  Shouldn't be hard to get rid
of 350W worth of steam...
From: R_Tim_Coslet@cup.portal.com
Newsgroups: sci.electronics
Subject: Re: PC board etching question
Date: Tue,  5 Jan 93 19:20:55 PST
Organization: The Portal System (TM)
  <1993Jan5.162702.18205@organpipe.uug.arizona.edu>
  <C0EGEy.DHL@zoo.toronto.edu>

>In article <1993Jan5.162702.18205@organpipe.uug.arizona.edu> dlatimer@iris4.ch
e
>m.arizona.edu (Darin Latimer) writes:
>>Is it possible to do your own through hole plating?  I have seen the
>>press in rivet type vias but was warned away from them as they tend to 
>>form flaky connections.  How is the through hole processing completed at a 
>>board house? ...
>
>They drill the holes, prepare the surfaces carefully, plate a very thin
>layer of copper on chemically, and then thicken it with an electroplating
>process.  That's a one-sentence summary of a complex and tricky process.
>It is not practical as a do-it-yourself exercise, not if you want reliable
>results.  Getting it to work dependably requires precise control of things
>like temperature and solution chemistry, which means spending several
>kilodollars on professional-grade equipment.
>-- 
>"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
>       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry

Add to that that even the profesionals goof up plated thru holes occasionally,
it really isn't anything a home experimenter wants to try to mess with.

I remember almost 10 years ago when the company I work for had to scrap a
whole batch of ASSEMBLED circuit boards because the plated thru hole's
barrels were intermitently seperating from internal traces (these were 8
layer boards). That PC vender was removed from the approved supplier list
and investigated to determine the cause (it turned out to be that they wern't
changing their drill bits frequently enough and the dull bits were making
bad holes that wouldn't hold the plating reliably).

                                        R. Tim Coslet

Usenet: R_Tim_Coslet@cup.portal.com
        technology, n.  domesticated natural phenomena
Newsgroups: sci.electronics
From: washer@sequent.com (Jim "Throw it over the wall" Washer)
Subject: How long should it take to erase a 705k1?
Organization: Sequent Computer Systems, Inc.
Date: Tue, 12 Jan 93 21:01:46 GMT

I tried to erase my 705k1 (from the eval kit). 15 minutes did NOT do it.
How long should it take?

 - jim  washer@sequent.com
From: massoud@chemteca.sdsu.edu (Massoud Ajami)
Newsgroups: sci.electronics
Subject: Re: "1-bit DAC"
Date: Wed, 6 Jan 1993 22:01:59 GMT
Organization: San Diego State University
NNTP-Posting-Host: 130.191.227.22

In article <C0F8Hp.84n@ve7frg.ampr.org> doug@ve7frg.ampr.org (Doug Collinge - VE7GNU) writes:
>From: doug@ve7frg.ampr.org (Doug Collinge - VE7GNU)
>Subject: "1-bit DAC"
>Date: Wed, 6 Jan 1993 07:22:37 GMT
>If my CD with a "1 bit DAC" and the aid of "8 times oversampling"
>can produce audio as good as an older CD with no "oversampling" and
>a 16-bit DAC then can my circuit with an 8-bit DAC be replaced
>with a 1-bit DAC and 4-times oversampling?
>
>How?  What's the math behind this concept anyway?

You are right but:
Eight times oversampling requires 2 bits dynamic range from sample to sample 
for the signal with 96dB abrupt change (16 bits). Since the voice and music 
don't have such changes, then, one bit range from sample to the next is 
suficient. The 8 bits and 4 times oversampling works if you don't saturate 
your DAC due to the fast rise/fall of the signal.
--
Peace and Prosperity!
  ---==< 110 >==---
From: wtm@uhura.neoucom.edu (Bill Mayhew)
Subject: Re: MouseSystems Mice
Organization: Northeastern Ohio Universities College of Medicine
Date: Fri, 08 Jan 1993 13:20:21 GMT

Not much software uses that middle button, though it is defined in
the protocol.  The only thing in recent memory I can think of is
Rix 2005 paint program.  I don't use that any more, but I think it
was used to nail down the corners of a polygon or something like
that.  You can emulate the third button by chording the L and R
buttons on the two button mouse; that might be handled by the
driver.o

-- 
Bill Mayhew      NEOUCOM Computer Services Department
Rootstown, OH  44272-9995  USA    phone: 216-325-2511
wtm@uhura.neoucom.edu (140.220.1.1)    146.580: N8WED
Xref: sparky sci.electronics:22252 rec.audio.pro:2717
From: system@hale.cts.com (System Administration)
Newsgroups: sci.electronics,rec.audio.pro
Subject: Re: Question: What to lubricate plastic pots with?
Date: Fri, 08 Jan 93 03:21:06 PST
Organization: Hale Telecommunications Inc.

tome@cs.umr.edu (Tom Erb) writes:

> I know, it's really a clause in the subject line, but I think it gets the
> point across. 
> 
> I maintain a small FM radio station, and we have many conductive plastic 
> potentiometers in our mixing boards. These things are fairly expensive.
> They get noisy after a while, but if I take them apart and clean/lubricate
> them, they never feel nearly as smooth as they did before. I've tried using
> "Big Bath" from ECG, and some other chemical from ECG that said "Cleans and
> lubricates potentiometers." I haven't taken apart any of the expensive slide
> pots yet as they haven't caused any problems, but the rotary pots have.
> 
> Reply by posting or email, I'll post a summary of any emailed responses.


Try cleaning them as usual and then lubericating with Breakfree CLP,
make sure it's the CLP and not regular Breakfree.  It's teflon in
suspension and after the recomended 2 hour curing time (If you can't have 
the board down that long, you can use it immediately) it leaves a
nice teflon residue that doesn't seem to conduct (no shorting pots.)

See your local gun shop for this stuff, better bicycle shops may also
have it.  Regular Breakfree works also, but is more like a light oil with 
teflon in suspension and it doesn't cure.

It should be safe for plastic pots, I use it in my slides with no 
problems, as well as my firearms.


Hale Telecommunications Inc.        Public Access Internet Site (hale.cts.com)
Owned by a happily armed            (619)/660-6734 V.32bis                
conservative republician.           NYC has gun control.                       
                
-----   Magic Johnson Knows How To Dribble More Than Just A Basketball!   -----
Newsgroups: sci.electronics