HDTenEightyP/NetNews huggingface dataset:
From: Jason.Goga@mailbox.bison.mb.ca (Jason Goga)
Newsgroups: sci.electronics
Subject: Multiple Floppy Copying
Date: 01 Oct 92  16:23:06 CST

 > From: smlg1015@uxa.cso.uiuc.edu (Stuart M Lichtenthal)
 > Path: inqmind!sys6626!bison!ccu.um
 > anitoba.ca!access.usask.ca!kakwa.ucs.ualberta.ca!alberta!ubc-
 > cs!destroyer!gumby!wupost!uwm.edu!
 > ux1.cso.uiuc.edu!news.cso.uiuc.edu!uxa.cso.uiuc.edu!smlg1015
 > Newsgroups: sci.electronics
 > Subject: Multiple Floppy Copying
 > Organization: University of Illinois at Urbana
 > Message-ID: <BvCBEs.3Cv@news.cso.uiuc.edu>
 > Date: Tue, 29 Sep 1992 12:44:50 GMT

 > Dear sci.electronics:

 > I'm looking for an inexpensive way to simultaneously DISKCOPY from drive
 > A to
 > 5 other floppy drives.  If you send me your responses, I'll be happy to
 > post a summary.

 > Stuart Lichtenthal smlg1015@uxa.cso.uiuc.edu

Lo, Stuart!

I forsee some small problems you'll need to overcome to get your idea to work. I propose a few ideas:

1) have six drives, all with perfectly syncronized spindles. Then just gate one to read the rest to write, apply the appropriate stepping pulses, and a wee bit of glue logic to turn off the write during steps and their corresponding re-syncs. This will no doubt require an amount of piddling with each floppy drive to incorparate an extra PLL to get them to sync properly. This would be ultra-cheap, however the drives would not be re-usable (without un-modification), and it would take a bit of skill to prefor








m such hacks.

2) have six drives, all adjusted within reasonable specs to the proper speed (read stock drives). Then have an amount of rather-fast sram (Xk x 1bit). Wait for the sync on the read drive, read and store the raw values (at considerable oversampling) from that into this ram, then:
a) have individual logic per write drive, and time shared buss arbitration, so that you may begin writing to each drive at a different time, but at the same speed. Then dump back the contents of the ram
b) have a separate ram's per drive and simply dump them back independantly, but read it all in at once.
The cycle would then return to the read drive and so on. This would be relatively inexpensive, depending however if you bought separate ram's per drive or just one global one. This by the way would be my choice, because it'de be cheap, simple, and the drives would be re-usable.

3) Have a WD279x controller and appropriate logic per drive, and at leaast a 68008 or 4Mhx 6502 servicing them all. and then continually read from the source and write to the destinations. This of course would be the most expensive, doubtful under $100. But by far would be the coolest.

Hope you find at least one of use.
-Jason

---
 * Origin: C.A. - FrontDoor (1:348/207)
From: mbevan@ersys.edmonton.ab.ca (Mark Bevan)
Newsgroups: sci.electronics
Subject: Switch for serial port.
Date: Fri, 25 Sep 92 15:56:01 MDT
Organization: Edmonton Remote Systems #1, Edmonton, AB, Canada

What pins are connected to the the switch on a RS232 dataswitch 
(a device used to connect 2+ peripherals to the same port without 
having to disconnect and connect).

Thanks Mark

Mark Bevan              mbevan@ersys.edmonton.ab.ca
From: ulrich@galki.toppoint.de (Ulrich Gall)
Newsgroups: sci.electronics
Subject: Re: Opening other people's Garage doors :)
Date: Sun, 04 Oct 92 18:36:54 GMT
Distribution: world               
Organization: private UUCP site, Kiel, Germany

johnr@mik.uky.edu (john s roberts) writes:
>
> In <kennehra.718059469@craft.camp.clarkson.edu> kennehra@craft.camp.clarkson.edu (Rich"TheMan"Kennehan) writes:
>
>
> >Hi.  I was wondering if its possible to construct a garage door
> >opener that can broadcast on any frequency you want so that you can
> >open other people's garage doors as you drive by :)
>
> >- Rich
>
>
> I have also wondered about this, however there is more to it than just
> locating the frequency, but also figuring out what type of code is sent.

If have the frequency, all you have to do is record what the garage door
opener transmits (just wait till someone opens it) and rebroadcast it when you
want to open the door.

A simpler way (and probably much more effective) is to try to get info from,
say, SEARS and have the 'opener' try out all the codes they have and then
start over - I don't think they have too many different codes.

But here we're getting closer and closer to helping burglars...



Ulrich Gall, Seebrooksberg 2, W-2300 Klausdorf, Germany
Tel.: +49-431-790292, EMail: ulrich@galki.toppoint.de
Newsgroups: sci.electronics
From: swanee@megadata.mega.oz.au (Geoff Swan)
Subject: Re: Audio + Speaker Design References
Organization: Megadata P/L, North Ryde, Sydney, Aust.
Date: Mon, 5 Oct 1992 23:29:18 GMT

In article <ga14RB3w165w@hale.cts.com>, system@hale.cts.com (System Administration) writes:
> 
> I'm looking for some good books or other sources for speaker enclosures,
> especially for car audio, and to a lesser extent, audio amplifiers for
> home and mobile use.
> 
> I have looked around locally, and been to the largest technical bookstore 
> here and havn't found a good reference outlining both proven designs on a 
> how-to level and going into depth into design considerations for
> your rolling your own.

Have a look at all the papers by Richard Small and Neville Thiele in
the Journal of the Audio Engineering Society (try engineering libraries
at your local university). I think the first series of articles in
sealed and vented box enclosures started around 1972. Otherwise look
out for a book (audio engineer's bible) by Berenak (I can't remember
the exact title). It contains information about everything from loudspeaker
and enclosure design all the way to microphone design. It's out of print
and VERY hard to get, but once again the local engineering library should
have one.

> Can a retangular tuned port be replaced with a tubular port of the same
> volume and depth?  It didn't seem to matter to me, but a friend of mine
> doing the same sort of stuff for a while wasn't sure either. 
  
Usually not. The port is very critical in vented enclosure design. Most
people tend to use circular ports rather than rectangular ones because
their performance is much easier to predict. Horn loaded enclosures
tend to use rectangular sections for a different reason (that's a
completely different kettle of fish).

    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: wayne@r-node.gts.org (Wayne)
Subject: 6845 CRT controller
Organization: R-node Public Access UNIX Information System (416-249-5366)
Date: Wed, 30 Sep 1992 19:25:52 GMT

I am workng on a project that uses the 6845 CRT controller and I am
having problems with tearing at the top of the screen when viewing the
image on a standard colour TV (through the appropriate RF modulator).
I am maintaining the horizontal sync pulses during the vertical retrace.
I know a standard NTSC signal uses equalizing pulses half as wide that
are half as wide but twice as frequent during the vertical retrace period.
Is this the problem? If it is what can I do to resolve it?

Please reply by email, I do read this group regularly but the expire
time on the system can be shorter than the interval between my logins at
times.
-- 
Wayne Dawe
wayne@r-node.UUCP
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Newsgroups: sci.electronics
Subject: Re: 25 ohm coax cable
Keywords: coax cable
Date: 5 Oct 92 15:15:12 GMT
Organization: AI Program, University of Georgia, Athens

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?

-- 
:- 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
From: gridlock@cats.ucsc.edu (Will Gridweed)
Newsgroups: sci.electronics
Subject: Re: Opening other people's Garage doors :)
Date: 5 Oct 92 01:38:29 GMT
Organization: University of California, Santa Cruz
NNTP-Posting-Host: am.ucsc.edu


ulrich@galki.toppoint.de (Ulrich Gall) writes:


>A simpler way (and probably much more effective) is to try to get info from,
>say, SEARS and have the 'opener' try out all the codes they have and then
>start over - I don't think they have too many different codes.

	My opener has a 10 dip switches for the code... 2^10 = 1024, not too
bad. I suppose it just depends on how long it takes to transmit each combination.

>Ulrich Gall, Seebrooksberg 2, W-2300 Klausdorf, Germany
>Tel.: +49-431-790292, EMail: ulrich@galki.toppoint.de

-Will

-- 
gridlock@cats.ucsc.edu
"He who lies, evil pays..."
From: miked@syscon.rn.com (Mike DeMetz)
Newsgroups: sci.electronics
Subject: Re: Mystery Part!
Date: 6 Oct 92 13:52:14 GMT
Organization: Syscon Corporate Headquarters - South Bend, IN USA
X-Newsreader: TIN [version 1.1 PL6]

The BUZ prefix sounds like a power MOSFET.
Newsgroups: sci.electronics
From: jhp@sactoh0.sac.ca.us (Jim H. Puga)
Subject: Finding info about chaser lights.
Reply-To: jhp@sactoh0.SAC.CA.US (Jim H. Puga)
Organization: Sacramento Public Access Unix, Sacramento, Ca.
Distribution: usa
Date: Thu, 1 Oct 92 03:39:00 GMT

I posted this once before but I think the board was having
a having when I posted, so I'll ask it again.

Does anyone know where I can find out how to make/learn
how chaser lights work?  I have some idea but it seems that
I would use too much wire to do it my way.  

Any and all help is appreciated.

Thanks in advance.
-- 
-------------------------------------------------------------
- jhp@sactoh0.SAC.CA.US    What else can I say?             -
-------------------------------------------------------------
Newsgroups: sci.electronics
From: ark1@cec2.wustl.edu (Alson Remington Kemp)
Subject: SPICE ftp sites....
Organization: Washington University, St. Louis MO
Distribution: usa
Date: Mon, 5 Oct 1992 18:40:04 GMT

	I need to do some SPICE modeling (who doesn't....) and I need
to find an FTP that has a lot of models on it.  I really don't want to
type in all the SPICE models myself and was hoping someone would know
of somewhere that SPICE models tend to congregate?  Help?
	thanx,
	 Al Kemp
	 ark1@cec1.wustl.edu
From: jmarin@messi.uku.fi (Jukka Marin)
Newsgroups: sci.electronics
Subject: Atari Portfolio
Date: 5 Oct 92 19:57:30 GMT
Organization: University of Kuopio, Finland
Originator: jmarin@messi.uku.fi

Dear All,

The end of the world is coming!  An Amiga fanatic bought an _Atari_ running
_MS-DOS_ !!

Ahem.

I bought a dead Atari Portfolio (a small palmtop) for $10.  After examining
it a few minutes I noticed that the display part was not getting any power
from the main machine.  The ultra-flexible cable that connects the two halves
of the machine is partially broken. :-I  I fixed it temporarily with an extra
wire but I'm pretty certain that more foils of the cable will break soon.

Does anyone know where I could get a new cable for this machine?  FAX-numbers?
I would like to fix this thing - it's too close to working to be thrown away
;-)

Another question: Does anybody have memory cards or an RS232 interface for
this machine that they would like to sell?  Schematics?  I guess it wouldn't
be very difficult to add one or two 128K*8 static RAM chips inside the machine
to increase the size of the RAM disk..  But the most important thing is to get
an RS323 interface to be able to transfer data between Atari and the real
world!

Any help appreciated.  Please e-mail.

  Jukka Marin


P.S. I _still_ love my Amigas! :-)



-- 
| Mail:  Jukka Marin         |     E-Mail:           jmarin@messi.uku.fi  |
|        Metsurintie 17 B 8  |     FAX/voice:        +358 71 232 793      |
|        70150 Kuopio        | There's God above computers -              |
|        FINLAND             |                       Love beyond the hate |
Newsgroups: sci.electronics
From: iqbal@pawnee.eel.ufl.edu (M.Iqbal)
Subject: Re: FAQ request
Organization: University of Florida
Date: Tue, 29 Sep 92 03:10:32 GMT

check archie data base: telnet  archie.ans.net
			login: archie
-- 

------------------------------------------------------------------
                                            
      						 >><<<     >>><<<<
Iqbal@sioux.eel.ufl.edu		 		 (o o)     (o) (o)
University of Florida				 [ | ]        | 
                                  		   -         ---

Newsgroups: sci.electronics
From: millsm@nextnet.csus.edu (Matthew Mills)
Subject: Looking for AC Analysis Program
Organization: California State University Sacramento
Date: Mon, 28 Sep 1992 22:46:01 GMT


Hello world,
   I am doing some AC timing analysis for digital circuits, mostly by
   hand and a little bit with Excel.  Is there any nifty programs out
   there that could make my life a little easier or faster? 
   Please EMail me any suggestions, if I get a good responce I will
   summarize in another posting.  Thanks!

   Matthew

-- 
| Matthew Mills                       | To do is to be - Socrates 
| Technical Lab Assistant (CSUS)      | To be is to do - Plato
| mail-> millsm@csus.edu              | Do Be Do Be Do - Sinatra
Newsgroups: sci.electronics
From: wilker@hopf.math.purdue.edu (Clarence Wilkerson)
Subject: Re: Electronics magazines & Mail order brides
Organization: Purdue University
Date: Mon, 5 Oct 1992 21:31:53 GMT

This could be a scam at the other end. That is, collecting money from
women to
place such ads. I imagine the ads in COMPUTER SHOPPER and such are
cheap compared to BYTE.
-- 
Clarence Wilkerson      \ Bitnet:       wilker%math.purdue.edu@purccvm
Prof. of Math. (topology)\ Internet:    wilker@math.purdue.edu
Dept. of Mathematics      \ messages:   (317) 494-1903, FAX 494-0548
Purdue University,         \ office:    (317) 494-1955 (voice/modem)
W. Lafayette, Indiana 47907 \ 
Newsgroups: sci.electronics,comp.robotics
From: mark@wdcwdc.sps.mot.com (Mark Shaw)
Subject: Re: 128K MAC, What to do, what to do?
Keywords: 128k mac
Organization: Motorola Western MCU Design Center, Chandler Arizona
Date: Tue, 6 Oct 1992 00:02:40 GMT

In article <pevzner.718301416@ceg.uiuc.edu>, pevzner@ceg.uiuc.edu (Vadim Pevzner) writes:
|> I've got 128k MAC, one of the chips burnout.
|> To fix it may cost upto $100. I also own
|> a dotmatr. printer and a modem. What should
|> I do with the MAC? Fix it? Upgrade it? Trash it?

There was an interesting article in last months (or was it June) MacUser
about a kit to turn it into an aquarium.

Mark
From: bell@plains.NoDak.edu (Robert Bell)
Newsgroups: sci.electronics
Subject: Tone (sound) chip info?
Date: 29 Sep 92 15:48:12 GMT
Article-I.D.: plains.20787
Distribution: na
Organization: North Dakota Higher Education Computing Network


Does anyone know of a chip that could take 4 bits as input and output the
information neccessary for a tone to be generated.  The 4 bits are there so
16 different sound combinations can be generated.  This chip would then be
hooked up to a speaker (with amplifier, etc. in between).  

Any info on a chip like this or similar (say takes 3 bits and generates 8
tones, or whatever) would be greatly appreciated.  This is for a project
for visually impaired school children.

Mail info to bell@plains.nodak.edu, or post if desired.

Thanks,
Rob
From: tmkk@uiuc.edu (Khan)
Newsgroups: sci.electronics
Subject: Re: The Communicator
Date: 2 Oct 92 16:18:17 GMT
Article-I.D.: news.BvI5AH.Mqn
Organization: University of Illinois at Urbana


In article <67001@cup.portal.com> Sam_-_Malone@cup.portal.com writes:
>
>My friend is an avid snowmobiler and was just asking me about a 
>product called "The Communicator". He says this device is popular
>amoungst snowmobilers, motorcyclists and the like. I sounds like it's
>a helmet mounted communications device voice activated for
>hands free operation. It operates (according to the
>manufacturer- Collett Electronics of Winnepeg Canada) 
>on the frequencey 49.8XXX Mhz. They will not give out any more
>information about their frequency since it's their mealticket.
>What Tim would like to do is... find out if a Radio Shack
>FM wireless communicator with proper frequency
>(the default frequency of the device from RS is 49.830 Mhz)
>would work in conjunction with "The Communicator" as is,
>or if it can be slightly modified to work with it.
>
>The reason for this is (natch) that the RS one is much much
>cheaper than "The Communicator".
>
>So, we have a couple questions:
>1. What is the exact frequency used in "The Communicator"?

Why not take a "Communicator" over to your closest Radio Shaft store and
broadcast some things from it while simultaneously using one of their
programmable scanners to search for your transmissions? You already know
the general area to search (49.8 MHz), so it should only take you a
couple seconds to find.

Once you know the frequency, ask the RS clerk if their unit will operate
at the same frequency, or if it can be modified to do so.
From: zoltar@glasgow.amigans.gen.nz (Grant Thoms)
Newsgroups: sci.electronics
Subject: Re: Telephone hacks!!
Date: 26 Sep 92 11:23:39 GMT
Organization: The .SIG research Department, General Enquiries Office

In article <1992Sep24.092436.24820@wam.umd.edu> mary@wam.umd.edu (Mary Louise Cassidy) writes:

` My primary reason is so I could stick the thing in the
kitchen nd it would let my roommates know when the phone is in use
and to NOT pick it up (as in interrupting modem calls!!).  Please
*EMAIL* all replies as I don't read this group much.  And if someone
has any other 'phone hacks' please mail them as well.'

And to think, I use a piece of paper with
`Grant on modem, don't touch' what planet have I been on all these
years?

Cheers,
Grant

-- 
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
        Grant Thoms (Zoltar) Co-Sysop of `Silent Imperium' BBS
  //                Zoltar@Glasgow.Amigans.Gen.NZ
\X/                             ----
         Standard Quote: `Insert $10 for the next 0.5 seconds'
                *** Opinions expressed are my own ***
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
From: cyberman@toz.buffalo.ny.us (Cyberman)
Newsgroups: sci.electronics
Subject: Re: '705c8 programming pr
Date: 26 Sep 92 18:17:39 GMT
X-Maildoor: WaflineMail 1.00r


   Wallace.r.blackburn was espousing about ''705c8 programming proble',
   on [09-24-92  20:31] to All!
 Wa> Do I have the serial port set right?  Is there an easy way to tell if
 Wa> the device is getting data from the PC?  Any suggestions?

    Try calling the circuit cellar BBS.  I'm sure Mr Carcia and
    those thier would be very willing to help I call thier once a
    well myself.  If you don't want to WELL I will put this
    message up on that BBS and see what happens.

        Stephen Cyberman@Toz.Buffalo.NY.US
        Scripted at Sat  09-26-1992  11:23:07

... End of Transmission........
--- Blue Wave/QWK v2.10
From: -Unknown-@mailbox.bison.mb.ca (-Unknown-)
Newsgroups: sci.electronics
Subject: cascade multiplier question
Date: 24 Sep 92 19:24:27 CST

Organization: Malaspina College


	How does a Cascade voltage multiplier work.  I fail to see how
a voltage increases going through a mess of diodes and capacitors.  Can 
anyone provide some theory.  Thanks
					chris.

 * Origin: The Electronic Mailbox (1:348/7.0)

Newsgroups: sci.electronics
From: dcheenne@unlinfo.unl.edu (Dominique J. Cheenne)
Subject: Test equipment for sale
Keywords: test,sale
Organization: University of Nebraska - Lincoln
Date: Tue, 29 Sep 1992 14:40:14 GMT

Test Equipment for sale
-----------------------

1) Leader LSW500/LBO500 Frequency analyzer: 2 channels, 20Hz to 300KHz, large
monitor, precision generator with markers. Channel 2 storage, harcopy
capabilities, etc... Still manufactured by Leader. A new unit costs $7,500.00.
 This one is 6 years old, in excellent condition, has manuals (owner +
service) and sells for $1,900.00.

2) Keithley 175A digital multimeter: 4 1/2 digits with autoranging, data
logging, references, conversion, etc... A precision instrument (bench type) in
excellent condition with all manuals. $200.00

4) GC5001 Frequency/period meter: 2 channels, 10 MHz range, with count,
interval, period, frequency, ratio, etc... with manual. $150.00

5) NLS MS215 oscilloscope: Miniature unit with 2 channels, 15 MHz.  Very small
(8" x 6.4" x 2.9"). Rechargeable batteries. With probes and manuals. $280.00

6) RCA WP707 power supply: 2x25V/2A. A wonderful unit, very reliable and
excellent noise performance. With manual. $200.00

7) Leader LM181 millivoltmeter: Precision unit for low level measurements. In
excellent condition with manual. $120.00

8) IQS FFT Analyser. Apple II based. Model 401 LX, 50 KHz with pulse generator
and built-in preamplifier. Complete with computer (2 floppies, monitor, etc..)
and all software. An excellent unit for loudspeaker investigation and basic
acoustical measurements. $900.00


Dominique J. Cheenne

dcheenne@unlinfo.unl.edu
(402) 474-2215
From: system@hale.cts.com (System Administration)
Newsgroups: sci.electronics
Subject: Audio + Speaker Design References
Date: 4 Oct 92 07:35:51 GMT
Organization: Hale Telecommunications San Diego CA

Hello--

A little background, I'm a student working on my BE degree and work
for the largest retailer of consumer electronics here in
San Diego.

I'm looking for some good books or other sources for speaker enclosures,
especially for car audio, and to a lesser extent, audio amplifiers for
home and mobile use.

I have looked around locally, and been to the largest technical bookstore 
here and havn't found a good reference outlining both proven designs on a 
how-to level and going into depth into design considerations for
your rolling your own.

I consider myself to be very knowledgible about such things, but having
a good reference starts me brainstorming my own designs, or
tweek in exsiting designs to make them work for me.

Is there a mailing list for this stuff?

Here's a question I havn't found an answer for yet--

Can a retangular tuned port be replaced with a tubular port of the same
volume and depth?  It didn't seem to matter to me, but a friend of mine
doing the same sort of stuff for a while wasn't sure either. 

Oh, anyone have a design for 4CX250b in audio?  ;-)


             -=-  System Administrator  system@hale.cts.com  -=-
                      Hale Telecommunications, San Diego
Newsgroups: sci.electronics
From: pngai@adobe.com (Phil Ngai)
Subject: Re: F-F-F-FAST ROMS 
Organization: Adobe Systems Incorporated
Date: Mon, 5 Oct 1992 16:48:28 GMT

Fast EPROMs and PROMs are nice, but what I could really use are
fast MASK ROMs. Big ones. There is no limit to the size of ROM
I can use....

But as a minimum, 4 megabit is probably the smallest one that
would do me any good.

-- 
My opinions are my own.
Happy owner of a new Mitsubishi Expo.
From: mcovingt@athena.cs.uga.edu (Michael A. Covington)
Newsgroups: sci.electronics
Subject: Re: HV transformer sources?
Date: 29 Sep 92 01:56:35 GMT
Distribution: usa
Organization: University of Georgia, Athens

In article <66792@cup.portal.com> CPS@cup.portal.com (CHRIS PATRIC SMOLINSKI) writes:
>Anyone know of any mail order sources for reasonably priced HV transformers
>suitable for Tesla coils? From what I've heard, neon sign transformers work
>pretty well.

There are neon sign shops in every town in the world...



-- 
+ Michael Covington - Artificial Intelligence Programs - U of Georgia - USA 
+ Unless otherwise noted, these are private opinions, not official statements.