HDTenEightyP/NetNews huggingface dataset:
From: sehari@iastate.edu (Babak Sehari)
Subject: Re: Microelectronics newsgroup
Originator: sehari@class1.iastate.edu
Organization: Iowa State University of Science and Technology, Ames, Iowa.
Date: Mon, 14 Dec 1992 17:13:16 GMT

In <javadi.834518132@genetics.com> javadi@genetics.com (Mountain Man) writes:

>---
>There were some talks of creating microelectronics newsgroup.  Is there
>any new news about this newsgroup?

It is still being voted upon, if you are interested in that newsgroup you
should send your vote to me sehari@iastate.edu in the following format:

your_Email_address, your_name, your_vote(either yes or no)

for example my vote looks like this:

sehari@iastate.edu, Babak  Sehari, yes

Vote only once. If you already voted, do not vote again.  Send only your
vote, any other material will be ignored.

                       With highest regards,
                            Babak   Sehari.


--
From: bhouser@sc9.intel.com (Brad Houser)
Newsgroups: sci.electronics
Subject: Re: "The Glob" Atari 2600 processors ???
Date: 17 Dec 92 22:48:54 GMT
Reply-To: bhouser@sc9.intel.com
Organization: Intel Corporation, California Technology Development


The "Glob" is called "Chip on Board".  It is an inexpensive way to package
the silicon chip.  The chip itelf is glued to the PCB, the bonding pads
of the chip are wired to the traces using an automatic wire bonder, and
then a hot glob of melted plastic is placed (globbed?) onto the chip.

Why isn't this done more often?  One reason is reliability.  It is 
likely to be less reliable than conventional plastic packages.

If it fails you basically replace the whole board.  In a higher priced system, 
you wouldn't take a chance of hermetically sealing the processor chip to 
the board much like you wouldn't wave solder a 486.
--
[Brad Houser                               Home of Pentium (tm)      ]
[                            bhouser@sc9.intel.com                   ]
[+1-408-765-0494                                                Woof!]
Newsgroups: sci.electronics
From: sakaria@vipunen.hut.fi (Sakari Aaltonen)
Subject: Re: 8051 -vs- 68HC11 ... summary ???
Keywords: 8051
Reply-To: sakaria@vipunen.hut.fi (Sakari Aaltonen)
Organization: Helsinki University of Technology
Date: Fri, 11 Dec 1992 17:06:29 GMT

In article <1992Dec9.124426.27299@ms.uky.edu> billq@ms.uky.edu (Billy Quinn) writes:
>I am wanting to gather info from users/developers regarding the main
>differences between 8051's and 68HC11's.  Also I am looking for a 
>sort of a 'favorite chip' vote.
>...........................................

IMHO, there are so many models/variants of both basic architectures made
that a _general_ comparison is almost impossible. Which model of the 8051
should be compared with which model of the 68HC11? There may be thousands
of permutations...
-- 
-----------------------------------------------------------------------------
Sakari Aaltonen                                 Email: sakaria@vipunen.hut.fi
"Unlike Gnu, a public-domain Unix look-alike system, MINIX is not vaporware."
                - Allen I.Holub, Dr.Dobb's, Jan '88 -
From: mycal@netronix.com (Just Mycal)
Newsgroups: sci.electronics
Subject: Modulating a VCO in a PLL
Distribution: world
Date: Sat, 12 Dec 92 01:23:32 GMT
Organization: Netronix, Inc.


Does anyone know where to find an example circut that shows how to
properly modulate the VCO section of a frequancy synth?

I need to modulate it with a 40khz fm signal.

Please mail me, we don't have sci.electronics for another 2 weeks.
(our uunet 3min a day time is low)

thanx mycal

-------------------------------------------------------------------------
Restrictions Suck!  Information is cool.                  |
Ignore info/freedom restrictors is the rule.              |
                                                        // \\
Your Pal Mycal -- mycal@netronix.com
Newsgroups: sci.electronics
From: mikel@networx.com (Mike Lempriere)
Subject: Building IBM PC TDD (need UART info)
Summary:  Building IBM PC TDD (need UART info)
Keywords:  IBM PC TDD UART
Organization: NetWorx
X-Newsreader: TIN [version 1.1 PL6]
Date: Wed, 16 Dec 1992 20:18:01 GMT

I'm building a TDD (Telecommunications Device for the Deaf) interface
for my IBM PC.

Several years ago, I built a phone line coupler, and analysed TDD signals
by means of timing loops on my Apple ][.  From this, I determined a bunch
of stuff, but due to the nature of my testing mechanism, I'd like
confirmation of these details:

a)  TDD baud rate is 45.5 baud (sheesh).
b)  Basic carrier (space tone) is 1400Hz.
c)  Mark frequency is 1800Hz.
d)  There is always 1 mark start bit.
e)  There are 5 data bits.
f)  There is always 1 space stop bit.  (Would 1.5 or 2 work too?)

IBM PC specific questions:

a)  What UART chips do the default OS/2 drivers talk to directly?
b)  What UART chips do the default MS-DOS drivers talk to directly?

Electronics misc:

a)  I have a 4-port serial card made by "STB Peripherals" containing
    a "StarTech ST16C554CJ" chip for all UART functions.  Does this chip
    allow access to the "External clock rate" pins, or did they just
    dump that functionality when they crammed 4 UARTs onto the one die?
    If so, what pins?

b)  I also have a combo card (IDE/Parallel/2-Serial).  It has a single
    (see above about lost part #) "Acer M5103A3E" (or maybe
    "TS6 A20448", it's an unfamiliar number) chip.  Same questions as
    above -- does it allow access to the "External Clock rate" pins,
    and if so, what pins?

c)  Alternative to a) and b) would be can you tell me how to get info
    on these chips, eg a manufacturer's address/phone, or a parts
    reseller that could get me the info?

d)  What's your favorite means of connecting your analog circuitry to
    the phone line?  Is there one particular chip/transformer/whatever
    that would make The Phone Company happy and provide me signal
    passthrough with isolation?  For testing, I just used an old
    audio transformer I had in a box under the workbench.
Newsgroups: sci.electronics
From: wtm@uhura.neoucom.edu (Bill Mayhew)
Subject: Re: How does EEG's work?
Organization: Northeastern Ohio Universities College of Medicine
Date: Sun, 13 Dec 1992 03:15:41 GMT

The best place to start is to go to a medical library and check out
books on neurobiological techniques.  My experience has been from
being a volunteer subject.  An electrode is designated as an
indifferent from which potentials will be measured.  Following a
chart of standardized stereotaxic coordinates, other electrodes are
placed on the scalp.  Occasionally, a second reference electrode is
placed on the head to pick up electromyographic response from eye
blinks, and other facial muscular response.  This is helpful for
removing muscle artifact from the EEG response.

The electrodes are usually small gold (plated?) cups that are
filled with a conductive paste that looks like toothpaste.  The
electrodes are taped in place.  Removing the tape and getting the
paste out of your hair later on isn't a lot of fun, but this is
science, you know.  I belevie you can get the paste and electrodes
from the Grass Instrument company.

The EEG response is pretty tiny - only a few microvolts.  The
amplifiers on the set-up to which I was connected had a gain of
10^4 and a frequency response of about .5 - 3000 Hz.  I had to
perform a task of trying to distinguish two slightly dissimilar
current stimuli.  The researchers were looking for specific
cortical evoked potentials and also looked for what was hoped would
be cellular responses by high pass filtering the resultant data.

There diagnostic EEG tests taht look for certain well known evoked
potential responses that occur at known latencies following the
onset of a stimulus.  An audio click stimulus can be used to
generate a BSEP resonse.  A trained technician can make neural
diagnostic assesments by observing the BSEP.  I suspect that
diagnostic type EEG equipment may be much simpler than that used
for research applications because a specific response is
investigated.

The other thing you want to watch out for is strict adherence with
safety procedures when you go about wiring up people to devices.
Battery powered amplifiers with optical or RF isolation are a good
idea.  Everything should be fused with fast acting very low mA
fuses too.

Joseph Carr has written several good books for do-it-yourself
computer interfacing and biological projects. 


-- 
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
Newsgroups: sci.electronics
From: mike@vpnet.chi.il.us (michael kamlet)
Subject: Power supply for chips
Organization: Vpnet - Free Usenet access
Distribution: na
Date: Wed, 16 Dec 1992 16:55:58 GMT

I'm trying to build a circuit using some D Flip-Flops.  The chips say they are
rated up to 16V (from a low of like 5 volts) so I figured I'd use a 9 volt
battery.  Well I tried that, and hooked up a partial circuit.  Evidently
I didn't have enough current since setting the SET to 1 did not produce
the correct output...

Any help would be appreciated...

Thanks

	Mike Kamlet
	mike@vpnet.chi.il.us

Newsgroups: sci.electronics
From: philip@mentorg.com (Philip Peake)
Subject: Re: Where to find X10 stuff?
Date: Fri, 18 Dec 1992 21:28:39 GMT
Distribution: or
Organization: Mentor Graphics
Keywords: 
Followup-To: 

In article <1992Dec16.194820.9279@sequent.com>, dog@sequent.com (Paul Parenteau) writes:
|> I'm looking for a local or fairly local source of X10/Powerhouse modules
|> and controllers.
|> 
|> Sears used to carry the stuff.  Heath/Zenith used to, but they went out of
|> business.
|> 
|> Radio Shack sometimes has their stuff, but I gave up on them years ago.
|> 
|> I know I can mail order from X10 directly, but there must be someone in the
|> greater Portland area who stocks this stuff.  
|> 
|> Does anyone know?

The Incredible Universe has some - unfortunately,
Incredible Universe = Tandy = Radio Shack, but at least its
an "up market" Radio Shack ...

Philip
Newsgroups: sci.electronics
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Band pass filters
Date: Sun, 20 Dec 1992 03:22:33 GMT
Organization: U of Toronto Zoology

In article <1992Dec18.133346.7262@sol.ctr.columbia.edu> brown@ccit08.duq.edu (Jason Brown) writes:
>Anyway, it occurs to me that using some combination of resistors and  
>capacitors in an RC circuit one should be able to filter out all but a  
>given frequency from an analog audio source.  The ultimate goal here would  
>be to set up a number of filters at different freqs. and send the output  
>of these filters to log. dot/bar display drivers yielding a spectrum  
>analyzer.

It's hard to make RC circuits that do well at this.  They tend to have
wide passbands with gradually-sloping edges, and to lose a lot of the
desired signal in the course of attenuating the rest.

Fortunately, there are prepackaged filter ICs that do an excellent job
of this kind of thing.  The buzzword to look for is "switched-capacitor
filter".  National's MF01 was the pioneer, but I'm sure there are better
ones now.
-- 
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry
From: cyberman@toz.buffalo.ny.us (Cyberman)
Newsgroups: sci.electronics
Subject: Re: Color Computer 3 inte
Date: 16 Dec 92 00:51:13 GMT
X-Maildoor: WaflineMail 1.00r


  Sir Richardson spoke forth saying:
"Re: Color Computer 3 inte" toward 
 on 12-14-92  17:12
 MR> On a similar vein, about 3 months ago I tried to get a digitized
 MR> sound driver working under level II, using the FIRQ.  The idea was to
 MR> use the empty space in $FExx and vector the FIRQ there, bypassing the
 MR> OS9 stuff (which was sloooow, and would crash if used!).  I got to the
 MR> point where I had a simple square wave generator running in ~$10
 MR> bytes, and which worked.... for a bit.  It would always crash after a
 MR> while, tho, as it seemed the IRQ was interfereing somehow.  So I
 MR> finally dropped it.  Too bad, a background sound driver would have
 MR> come in real handy.

    Where does MicroWare hide the kernal?  If I remember there is
    a task switch map.  (T0/T1).  this allows the computer to
    rapidly switch to the kernal and then return to the program.
    The question is how do they implement it?

SYSTEM MEMORY MAP:
 RAM      00000 - 7FFFF (512K bytes)
 ROM      78000 - 7FEFF when enabled
 I/O      XFF00 - XFFFF I/O space and GIME regs
 
64K PROCESS MAP:
 RAM       0000 -  FEFF (possible vector page FEXX)
 I/O       FF00 -  FFFF (appears in all pages)

    now acording to this FExx is NOT empty.

Note: the Vector Page RAM at 7FE00 - 7FEFF (when enabled), will appear instead
 of the RAM or ROM at XFE00 - XFEFF. (see FF90 Bit 3)

And this states the Vector page RAM is there when enabled.
That may have more to do with your problem.  I was considering
constructing a MOD player for the COCO (that would be cool).
of course the big limitation is memory (as ussual).  Another is
adjusting the interupt rate (60hz on the CC][ the CC]I[ has a
variable one).

To solve the memory problem I figure I can chop the lower 4
bits on each sample byte.  Then one can have 2x the sample space.
This wouldn't make a difference since the D/A has only 6 bits of
resolution anyway! (add 4 4 bit samples the result is 1 6 bit
value).  It may not sound great but it might be a first for the
Coco (who cares?).  It might be able to only work on the CC3
because it may be the only coco FAST enough to do the digital
mixing.

				Stephen Cyberman@Toz.Buffalo.NY.US
			 Mangled on Tue  12-15-1992  at 17:51:19

... Click ... click ... click ... damn, out of taglines!
---
 * Blue Wave/QWK v2.11 *
                                                                                                           
Newsgroups: sci.electronics
From: pvr@wang.com ()
Subject: Re: Need help with PADS shareware
Organization: Wang Labs, Lowell MA, USA
Date: Tue, 15 Dec 1992 14:23:12 GMT

washer@sequent.com (Jim Washer) writes:

>I've been playing with PADS logic and pcb, and have managed to 'capture'
>my schematic, create the netlist, and read it in using pcbshare.

>I have not managed to route it (auto route I hope), nor print a postscript
>image of the etch (single sided board).

   Did you place the parts?   You can use auto-place, but that is
more complicated.   When you read in the net list all parts are
piled on top of each other at the origin (0,0).   This is at
the lower left of the screen by default.   It can be off the
screen if you have scrolled the drawing area.   To see them
easily zoom in on the origin to blow the parts and use the move
command to pull them where you want.   Then you can use auto-route.

Hope that this helps.

--
>>>>>>>>>>>> Peter Reilley ..... pvr@wiis.wang.com ..... KA1LAT <<<<<<<<<<<<<
                     Well, that about says it.
Newsgroups: sci.electronics
From: walvdrk_r@research.ptt.nl (Kees van der Wal)
Subject: Re: 486DX2 Crystals
Organization: PTT Research, The Netherlands
Date: Fri, 11 Dec 1992 22:35:07 GMT

In article <1g4ul8INN2em@violet.csv.warwick.ac.uk>, esrej@csv.warwick.ac.uk (Mr
L A J Davis) writes: 

> I purchased a 486 motherboard fitted with a 486DX2 50MHz cpu. Unfortunately
> with no extra cooling the system fails to complete its bootup proceedure.
> The board is fitted with 33.3MHz crystal that can be replaced presumably
> for the different 486 cpu's the board is able to support.
> By cooling the cpu with a cold can out the fridge(very scientific) and
> I have managed to briefly run norton si which claims my processor is
> a 67MHz 486. My guess is that the crystal should be 25MHZ for the cpu
> to operate however on contacting the supplier he claimed that the crystal
> frequency didnt matter so long as it is high enough and reckons i need a
> 50 or 80 Mhz xtal which he is posting to me. Is this assumption correct?

My Taiwan motherboard with 486DX2-66 has a crystal of 33.33MHz. The
documentation prescribes a 25MHz crystal for a 50Mhz DX2 and a 50Mhz version
for a 50MHz DX. Also some jumpers have to be set.

> Logically I would say that the cpu frequency is directly related to the
> xtal frequency and therefore, as I have a dx2 50 the xtal should be 25MHz
> (or possibly some multiple of that)

This makes sense to me. Though I still wonder where my DX2 get's its 66MHz
clock from if the crystal runs at 33MHz only. Does it contain some internal
clock doubler circuitry? 

Regards, <kees>

PS. There is a fan right on top of the CPU's cooling fan.
Newsgroups: sci.electronics
From: bkr@drdhh.hanse.de (Bjoern Kriews)
Subject: Please help: clock doubling
Summary: how to double some digital frequency ?
Keywords: freq, digital, doubling
Organization: Digital Island
Date: Thu, 10 Dec 1992 10:34:24 GMT

Hello netland !

I have the following problem in speeding up the 68901 UART:

I want to double the frequency that is fed into the MFP as
rx/tx clock. This signal is derived from a 2.4576 MHz clock
that is accessible. The frequency range is 3000 Hz to 700 kHz
and the output pulse must remain synchronous to the 2.4576
Clock.

Any hints on how to digitally double some clock will be
greatly appreciated.

Solutions using gate-runtime are not applicable because the
spectrum is too wide.

Many thanks in advance for your efforts, 
  Bjoern

-- 
bkr@drdhh.hanse.de - Bjoern Kriews - Stormsweg 6 - D-2000 Hamburg 76 - FRG
--------------------------------------------------------------------------
Dec 27.-29.: 9. Chaos Communication Congress 1992 Eidelstedter Buergerhaus
Elbgaustr. 12, 2000 Hamburg 54, FRG + Mail me if you have questions.
Newsgroups: sci.electronics
From: danr@ais.org (Daniel Romanchik)
Subject: Re: Telephone Headsets
Organization: UMCC
Date: Mon, 21 Dec 1992 00:31:29 GMT

In article <1992Dec18.230348.18944@opus.hunt.inmet.com> lenny@hobbs.hunt.inmet.com (Lenny Goodman) writes:
>I've been looking into telephone headsets (the things that telephone
>operators usually wear) and the prices are much higher than I expected:
>$160 - $200 and UP.  Basically, the thing consists of half a headphone,
>a microphone, and a small amplifier.  I would have thought that the price
>would be $60 to $80.  Does anyone know why they are so expensive; or,
>does anyone know a source where the price is more reasonable??  Thanks.
>
>  -- Len
   I have and use a Plantronics headset.  I paid around $90 for it,
but I just noticed that a nearby Office Max is selling a similar model
for $75.  I like using it, except the received audio quality could be
better.  Sometimes it is hard to hear the other party.  No complaints
with the microphone, though.  Everyone I talk to says I sound fine.

Have fun, Dan

Newsgroups: sci.electronics
From: bg@ccwf.cc.utexas.edu (Brent Goodrick)
Newsgroups: sci.electronics
Subject: HP 48S Calculator to IBM-PC serial cable pin assignments?
Date: 13 Dec 92 04:04:01 GMT
Distribution: sci.electronics
Organization: The University of Texas at Austin, Austin TX

I am looking for the pin assignments for the serial cable that connects
an HP 48S calculator to the serial, RS-232 PC port (the cable can be
purchased from HP, but I don't wanna).  I would need to know the type
of connector that snaps into the back of the calculator.  If someone
could provide me with this information, I would appreciate it.

Thanks
Brent Goodrick
Internet --> bg@ccwf.cc.utexas.edu
Newsgroups: sci.electronics
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Subject: Re: Ranking the Electronic magazines.
Organization: AI Programs, University of Georgia, Athens
Date: Mon, 14 Dec 1992 05:52:43 GMT

Concerning QST, in the last few issues they are showing a welcome trend
toward having _more_ electronics (theory and practice) and less radio-
telegraphico-nostalgia.

-- 
:-  Michael A. Covington     internet mcovingt@uga.cc.uga.edu :   Verbum caro
:-  Artificial Intelligence Programs       phone 706 542-0358 :    factum est
:-  The University of Georgia                fax 706 542-0349 :  et habitavit
:-  Athens, Georgia 30602-7415 U.S.A.     amateur radio N4TMI :   in nobis...
Newsgroups: sci.electronics
From: simont@meiko.com (Simon Turner)
Subject: Re: Rechargeable lithium batteries?
Organization: Meiko Scientific Corp.
Date: Tue, 15 Dec 1992 12:27:11 GMT



As many people seem to be interested here are the details:

	Dowty Batteries
	18 Nuffield Way
	Abingdon
	Oxfordshire	OX14 1TG
	ENGLAND

	UK Tel +44 235 520502
	UK Fax +44 235 535766

I don't know if there is a US office but there may well be.

Simon

Newsgroups: sci.electronics
From: snydert@dmapub.dma.org (Tony Snyder)
Subject: The Electric Car
Organization: Dayton Microcomputer Association: Dayton, Ohio
X-Newsreader: TIN [version 1.1 PL8]
Distribution: usa
Date: Sat, 12 Dec 1992 04:07:14 GMT

Something you might look at is the November '92 issue of the IEEE
Spectrum magazine.  It has a big spread on electric vehicles.  It 
is their cover story.  Let me know what you think.  I was surprised to 
find the  Spectrum on a news-stand.
 
s
Newsgroups: sci.electronics
From: whit@carson.u.washington.edu (John Whitmore)
Subject: Re: Switching speakers on during loud volumes
Summary: Soft turn-on with photoresistor
Organization: University of Washington, Seattle
Date: Wed, 16 Dec 1992 05:56:18 GMT

In article <Bz6nyz.LF4@acsu.buffalo.edu> v064mb9k@ubvmsd.cc.buffalo.edu (NEIL GANDLER) writes:
>
> I am designing a device that disconnects a pair of speakers from a
>stereo recevier when the phone rings. But when the phone is eventually
>hung up m afraid that suddenly switching back a pair of speakers with a
>relay during high volumes can sort of "overwhelm" a pair of
>sepakers

	If you just want to mute the receiver, DON'T use a relay
in the (high-current) speaker wiring.  Instead, put a two-resistor
attenuator in your tape monitor loop, with the grounded resistor
being a photoresistor (most convenient way to do this is with
a lamp/photoresistor style optical isolator).

	When you light the light, the photoresistor turns ON
and mutes the stereo; when you remove the light, the photoresistor
slowly (takes a few milliseconds) turns off (and you can make
it slower by powering the light through an RC circuit).
Noise is negligible, because no current passes in the
photoresistor while the stereo is ON.

	If you have the schematics for the preamplifier, it would
be easy to build this gizmo into the box (it only takes a few cc
of volume).  And, it DOESN'T induce sharp switching transients.

	John Whitmore



Newsgroups: sci.electronics