HDTenEightyP/NetNews huggingface dataset:
From: agodwin@acorn.co.uk (Adrian Godwin)
Newsgroups: sci.electronics
Subject: Re: TEC-200 film
Date: 12 Nov 92 13:15:45 GMT
Organization: Acorn Computers Ltd, Cambridge, UK

In article <BxK0B5.Hs2@wang.com> pvr@wang.com writes:
>
>	If the film could be pressed onto the board with
>a very tightly controlled pressure at the correct temperature
>then this process would probably work well.   An iron is
>just too crude an instrument.
>

How about a trouser press, or one of those hot ironing boards used for shirts ?
Or a contact heater (used, I think, to put a glaze on photographic prints). 


I'm still trying to get the plotter to work before trying the direct-plot method, 
but I see that several people have made double-sided boards using one or other 
of these methods : how did you manage to get good registration between the two sides ?

-adrian

-- 
Adrian Godwin : agodwin@acorn.co.uk : adrian@fangorn.demon.co.uk : g7hwn@gb7khw
ObDisclaimer  : I believe this rubbish .. don't imagine that anyone else does.
Newsgroups: sci.electronics
From: more_da@pts.mot.com (DAN MORERA)
Subject: Re: 12 V -> 3V, 0.6 A
Followup-To: Re: 12 V -> 3V, 0.6 A
Reply-To: more_da@pts.mot.com
Organization: Paging and Wireless Data Group
Date: Tue, 10 Nov 1992 19:01:55 GMT

Concerning the 12V to 0.6 V issue, I thought I would throw my two cents in.

I would go with the LM317 approach as someone previously suggested.
However, since the car battery does swing over a couple of Volts, I think
that regulating the battery voltage to 5 Volts with a 7805 (Bt suffix should
suffice) would probably give you a little better performance.  I use such circuits
at work when I need several precise voltages for cicuits when using one common
AC - DC power jack instead of several power supplies.
---
**********************************************************************
* "Could be worse -- could be raining."  *  Daniel Morera            *
**********************************************************************
*                                        *  more_da@pts4.pts.mot.com *
**********************************************************************
From: mycal@netronix.com (Mycal Johnson)
Newsgroups: sci.electronics
Subject: IR anamal locator
Distribution: world
Date: Fri, 13 Nov 92 00:28:30 GMT
Organization: Netronix, Inc.


Has anyone seen a product called the "Heat Seeker"?   I don't know if
it is IR or what, but it claims that it can detect human sized targets
up to 1000 feet.  It is supposto sense less than one degree temperature
change, though woods and busy terrain.

Anyone got an Idea on what this is and how it works?

They sell them in a para-military catalog called U.S. Cavalry.

thanx
mycal


Mycal Johnson                          _
mycal@netronix.com                    | |_ _ _         There is only one
(707)769-3309                         | | | | |__          nor-cal
-----------------                     |        ___\         so-cal
   -  -  -  -                          \      /              mycal
     Ban all Bans                       |    |
Newsgroups: sci.electronics
From: hcb@netcom.com (H. C. Bowman)
Subject: 26LS31 / 26LS32 Differential Pair Help
Keywords: Differential line drivers, data communications
Organization: Box of Rain Productions
Date: Mon, 9 Nov 1992 21:10:23 GMT

Hullo--
If you have experience with data communications across electrically-noisy
lines, I could use your help!  I'm about to use the above devices in a
new project, and I'd like to get a quick hints-and-kinks briefing about
what to watch out for.  Please send me a note at hcb@netcom.com and I'll
reply with suitably clueless questions.  Many thanks!

--Cliff

-- 
| Cliff Bowman     |(501) 968-2232 Voice | As of 1 November, 1992, I was |
| Electronics Dude |(501) 964-6118 Pager | approximately $1,018,555 shy  |
| Innovation Ind.  |(501) 968-7986 Fax   | of being a millionare.        |
Newsgroups: sci.electronics
From: dag@col.hp.com (David Geiser)
Subject: Re: Radar Detectors
Date: Thu, 12 Nov 1992 21:23:58 GMT
Distribution: usa
Organization: HP Colorado Springs Division

> 
>   I am in the market for a radar detector. Any reccomendations ?

Pay cash.
-- 

 Boycott Colorado.
Newsgroups: sci.electronics
From: ajackson@ernie.Princeton.EDU (Andrew William Jackson)
Subject: Re: TEC-200 film
Originator: news@nimaster
Organization: Princeton University
Date: Tue, 10 Nov 1992 01:47:07 GMT

TEC-200 film

Has anyone tried this stuff?  Supposedly you photocopy your
PCB pattern onto it with a normal photocopier and then iron
it onto a blank copper board, peel off the plastic substrate
leaving the pattern behind - then you etch it.  Sounds like
a great way to make boards without the hassle of using photo
resist.

Andrew Jackson  ajackson@ernie.princeton.edu
From: ccjensen@fnal.fnal.gov (Chris Jensen)
Newsgroups: sci.electronics
Subject: AC Motor PWM Controller
Date: 6 Nov 92 23:14:19 GMT
Article-I.D.: linac.24UFE_BER
Distribution: usa
Organization: fermilab
X-Xxmessage-Id: <A720595030011099@jenson.fnal.gov>
X-Xxdate: Fri, 6 Nov 92 17:18:08 GMT
X-Useragent: Nuntius v1.1.1d9

There was an add a couple of months ago in Electronic Design or similar 
magazine about a single phase and three phase controller for AC induction
motors. I called the company, in California I believe, and then threw away
the ad. Does anyone know the company or the part number?
Thanks, Chris Jensen
email to ccjensen@fnal.fnal.gov
From: stanb@hpnmdla.sr.hp.com (Stan Bischof)
Date: Wed, 11 Nov 1992 16:07:45 GMT
Subject: Re: beryllium copper
Organization: Hewlett-Packard, Santa Rosa, CA
Newsgroups: sci.electronics

In sci.electronics, cyberman@toz.buffalo.ny.us (Cyberman) writes:


>    Though your first statement is correct the second is not.
>    BeO is generally WHITE in appearance.  Now they made either
>    add impurities or use a different process to get black BUT
>    reading the Handbook of Chemistry and Physics states it
>    WHITE as mr Wallace stated.

                               
Thanks for the info. My statement was based only on personal experience 
with BeO- and I clearly stand corrected!

Stan Bischof
HPSR
From: neal@cmptrc.lonestar.org (Neal Howard)
Newsgroups: sci.electronics
Subject: Re: looking for non-conducting, low viscosity, teflon compatible fluid...
Date: 10 Nov 92 21:46:48 GMT
Organization: CompuTrac Inc., Richardson TX

In article <1992Nov10.143513.14412@athena.mit.edu> jory@athena.mit.edu (Jory Bell) writes:
>as usual, i have a slightly weird interdisciplinary
>question...
> 
>in a nut shell, i am looking for a non-conductive, low
>viscosity, teflon-compatible fluid which i can put in an
>oceanographic instrument with some electronics (IC's,
>motor, and batteries) as a pressure compensating fluid!
> 
>some net folk may be familiar with fluorinert (FC-77), a 3M
>chemical used for electronics testing (heat cycles,
>etc?)... well i have been using this as a pressure
>compensating fluid, but it is "incompatible" with teflon
>(it makes it expan from 3%-7%), and it is keeping me from
>using a certain teflon shaft seal that i have me heart set
>on...
> 
How about DOT-5 automotive brake fluid??? It's pretty low viscosity over a
wide range of temperatures and doesn't harm teflon parts inside brake systems.
Since it's silicone based, I doubt that it has any substantial amount of
electrical conductance either. It's also non-hydroscopic and reportedly will
not dissolve paint like the glycol based brake fluids. It's probably also got
some semi-decent lubricating properties for your electric motor too.

-- 
=============================================================================
Neal Howard   '91 XLH-1200      DoD #686      CompuTrac, Inc (Richardson, TX)
     "To do is to be." - Socrates      "To be is to do." - Aristotle
                       "Doo bee doo bee doo." - Sinatra
=============================================================================
From: paula@nlbbs.UUCP (Paula Stockholm)
Newsgroups: sci.electronics
Subject: Very annoying Humm on home stereo
Date: Wed, 11 Nov 92 12:26:09 GMT
Reply-To: paula@nlbbs.UUCP
Distribution: world
Organization: The Electronics Workbench



        In article <1992Nov10.054130.50347@ns1.cc.lehigh.edu>
        ebd0@ns1.cc.lehigh.edu writes:

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

        Off-the-cuff: Change every big capacitor in sight. Slightly more
        technical: The power supply capacitors may be drying out and
        need replacement.

        If it _is_ a tube amp, and if you can still find a tube tester,
        check for shorts in the tubes.

        A servicing note: Emerson bought the Scott name a few years
        back. I doubt they can be of much help.

        
           Paula Stockholm              paula@nlbbs.UUCP        
          Cumberland, Maine          !nlbbs!paula@uunet.uu.net
From: smckinty@sunicnc.France.Sun.COM (Steve McKinty - Sun ICNC)
Newsgroups: sci.electronics
Subject: Re: British sound with German TV
Date: 9 Nov 1992 13:26:24 GMT
Organization: SunConnect
Distribution: world
NNTP-Posting-Host: hardy.france.sun.com
Keywords: TV, Philips

In article <1992Nov9.110756.15219@EE.Surrey.Ac.UK>, M.Griesser@ee.surrey.ac.uk (Michael Griesser) writes:
> Hello !
> 
> I've got a Philips TV-Tuner connected to my computer monitor.
> It's a German type, and when I brought it to England I noticed,
> that it wasn't able to receive sound here. I think, there's
> another distance between picture and sound signals here than
> elsewhere.

Yes, German TV (like most of W. Europe) has the sound subcarrier at
5.5MHz from the video, whereas the UK & Ireland use 6MHz.

> Is it possible to get the sound by minor changes ? The tuner
> component is a UV417, the sound decoder is a TBA120SQ.

If its a reasonably modern TV it should be a fairly simple matter
of replacing two ceramic filters in the IF stage. Any Philips
dealer should be able to do it for you. If you want to do it
yourself you'll need to find the filters, which look like 3-legged
ceramic capacitors. There are usually two, each is slightly different
from the other. Both should have an assortment of numbers and letters
containing the sequence "5.5"

One will be connected to the TBA120, filtering the sound signal going
in, and the other will be on the Video processing chip, preventing the
sound signal getting in.

Finding the proper replacements might be tricky, although TV shops
which repair Philips equipment should stock them.

Steve

-- 
Steve McKinty
SUN Microsystems ICNC
38240 Meylan, France
email: smckinty@france.sun.com	   BIX: smckinty
From: aslt@acad2.alaska.edu
Newsgroups: sci.electronics
Subject: RS-232 ASCII -> NTSC ?
Date: 10 Nov 92 01:24:03 GMT
Article-I.D.: acad2.1992Nov9.212403.1
Organization: University of Alaska

Hi,

Is there such an animal as an RS-232 (or RS-442) ASCII to an NTSC 
composite video converter?  Kind of like a dumb terminal except 
to an NTSC monitor? (keyboard not needed)

Thanks in advance.  E-mail replies welcome.

Lee
From: cyberman@toz.buffalo.ny.us (Cyberman)
Newsgroups: sci.electronics
Subject: Re: Motor controller help
Date: 11 Nov 92 02:15:26 GMT
Article-I.D.: toz.gate.Fsy2TB1w165w
X-Maildoor: WaflineMail 1.00r


    Jonas R Klein entitled a message as 'Motor controller help wan',
   on the 11-07-92  20:27 to All.
 JRK> The motors are small, and I'm using 2n2222 style transistors form
 JRK> Radio Shack, since they're cheap and easy to get, but I still need 72
 JRK> of them and a lot of wire.  Can I do this more easilly from a bipolar
 JRK> supply? How does everyone alse do it? I haven't beena able to find many
 JRK> circuits that do this.

    It is MUCH easier to control them with a split voltage
    supply.  This requires only 2 transistors (bjt or Mosfet)
    per motor, 1 NPN and 1 PNP.  The ttl can be channeled to a
    level convertor.  This will allow +-5v for control instead
    of 3.2 and .31 (ussual ttl output).

    You might be able to use the 1488 (ttl -> Rs232 level
    convertor) or a voltage comparitor.  Depends on what you are
    doing.

    The connection is like this
           EN       ~EN
           ____     ____
    +5v ___/  \_____/  \___ -5v
           npn   |  pnp
                ( )
                 |
                Gnd

    Please note that the NPN is active high input and the PNP is
    active low.  This is a complementary semetry amplifier.  If
    you don't want to use PNP you can use an npn instead.
    However this allows you to use a matched pair.  ALSO it
    means you have 3 states a nuetral and 2 oposing flow states.

    Cyberman

... DISK CRASH BBS - 360K ONLINE
--- Blue Wave/QWK v2.10
From: stock@acsu.buffalo.edu (Matthew D. Stock)
Newsgroups: sci.electronics
Subject: 68HC11 assembler/C compiler
Date: 12 Nov 92 03:28:19 GMT
Article-I.D.: acsu.BxL2z8.2Fu
Organization: State University of New York at Buffalo/Comp Sci

Hello all,
  I have been thinking of writing a cross-assembler and/or C cross-compiler
for the 68HC11 over winter break.  It would be written for unix systems.  I
was wondering if there was any interest in something like this on the net.
Also, has this been done already, and how good of an implementation was it?
Any suggestions/comment would help.  If I actually DO get the project off
the ground, I would also need beta testers, so let me know if you are
interested.

Please email responses, and I'll post info on what I find.

Thanks,
  -Matt


-- 
Matthew D. Stock         | think(X):- am(X).
stock@cs.buffalo.edu     | think(i).
			 | :? am(i).
CS @ Buffalo             | yes.
From: mcs@wet.UUCP (Gil Nardo)
Newsgroups: sci.electronics
Subject: Re: 486 CPU KOOLERS FOR SALE
Date: 9 Nov 92 19:57:39 GMT
Distribution: usa
Organization: Wetware Diversions, San Francisco

u9147063@cs.uow.edu.au (Richard Barry Ling) writes:
[#@$! discussion deleted]
> I generally find my girlfriend's heat goes up exponentially if I insert my
> purple-helmeted warrior (tm) into her gaping pussy and pump hard.  Is this a
> very specific system?
> 

Inserting your number 2 pencil warrior (tm) into a toaster
is not at issue here.
-- 
Gil Nardo                  | mcs@wet.com
Migrant Computing Services | (415)664-1032
1032 Irving Street, #435   |-----------------
San Francisco, 94122       | Supernova = *!
From: f92anha@fy.chalmers.se (Anders Hammarqvist)
Newsgroups: sci.electronics
Subject: Re: Help: What is an Independent Current Source!?
Date: 10 Nov 92 15:27:55 GMT
Organization: Chalmers Univ. of Technology, G|teborg, Sweden

In article <Nov.9.00.11.39.1992.9368@clam.rutgers.edu>, steuer@clam.rutgers.edu (robert Steuer) writes:
|> I understand an Independent Voltage source is like a battery and I
|> understand that an Independent Current source can supply a current,
|> but what is a REAL-LIFE example of an Independent Current Source?
|> I have asked fellow students, my teachers, even a teacher with a
|> Doctorate Degree and still I get hmmm, thats a good question!
|> 
|> -------------------------------------------------------------------------------
|> | Robert Steuer               Internet: steuer@clam.rutgers.edu               |
|> | Rutgers University          Amateur Radio: KF2EK@N3FOA.#EPA.PA.USA.NA       |
|> -------------------------------------------------------------------------------

Well, my father told me about a real-world application for an independent
(constant) current source, which is not exactly what you asked for, but
might be of help anyway... In the old days (before high-power halogen
lamps?) they used an arch-light in the movie projectors used in theaters.
This device consisted of a constant current source and two electrodes. To
start the thing, the electrodes were shorted and the supply switched on. The
electrodes were then moved apart and an arch formed between them. 

I also believe that and electric welder is a constant current source.

Anders Hammarquist, f92anha@fy.chalmers.se
Newsgroups: sci.electronics
From: miked@syscon.rn.com (Mike DeMetz)
Subject: Re: Wanted: Info on Altair 8800b
Organization: Syscon Corporate Headquarters - South Bend, IN USA
Date: Thu, 12 Nov 1992 21:25:30 GMT
X-Newsreader: TIN [version 1.1 PL6]

Check your library for old (75-80) issues of Popular Electronics
Kilobaud Microcomputing,BYTE,Dr. Dobbs. It uses the orginal S100
bus. You can probably find cards at give away prices at some hamfests
or swapmeets. If it is in orginal shape it is a good collectors item.

Newsgroups: sci.electronics,misc.forsale.computers.pc-clone,misc.forsale.computers.d
From: legrady@ug.cs.dal.ca (Tom Legrady)
Subject: Re: 486 CPU KOOLERS FOR SALE
Organization: Math, Stats & CS, Dalhousie University, Halifax, NS, Canada
Date: Thu, 5 Nov 1992 22:48:19 GMT

In article <Bx93z4.n2B@cs.dal.ca> legrady@ug.cs.dal.ca (Tom Legrady) writes:
>
>I would suspect ( but without any evidence ) that similar effects hold
>with electronics, that a relatively minor reduction in heat would have
>a great effect on life and operation.

What I should have added is that if a component is operating under its
rated operating temperature, it should live long and prosper. However,
when you get to the operating temperature boundary and hotter (or even
a little before you reach that boundary ), every extra calorie of heat
cuts in the the expected life of the component in a big way. In this
circumstance a cooler whould make a big difference. If the component
is oeprating under its rated temperature, cooling it will have little
effect. It's usually 'bargain' designs and designs which try to get
every ounce of compute power out of a chip, that are most like likely
to be running hot. 

Tom Legrady
From: jimc@tau-ceti.isc-br.com (Jim Cathey)
Newsgroups: sci.electronics
Subject: Re: Phone line monitor
Date: 12 Nov 92 18:45:54 GMT
Organization: ISC - Bunker Ramo, Spokane, WA

In article <1992Nov11.130157.21099@email.tuwien.ac.at> ch@eiaut2.tuwien.ac.at (Christian Kral) writes:
>There is a simple possibillity of getting rid of this kind of problems,
>using a two channel scope which can add both inputs and invert one. 

_Provided_ that the two signals lie within the common-mode rating of the
vertical amplifiers.  (For phone lines, this is probably OK.  For
something evil like an RS-485 line driven by a 'hot-chassis' power
supply, you might have some trouble!)

-- 
+----------------+
! II      CCCCCC !  Jim Cathey
! II  SSSSCC     !  ISC-Bunker Ramo
! II      CC     !  TAF-C8;  Spokane, WA  99220
! IISSSS  CC     !  UUCP: uunet!isc-br!jimc (jimc@isc-br.isc-br.com)
! II      CCCCCC !  (509) 927-5757
+----------------+
			"PC's --- the junk bonds of the computer industry"
From: billw@regal.cisco.com (William )
Newsgroups: sci.electronics
Subject: Re: Idea for LED sequencer
Date: 4 Nov 92 22:31:43
Organization: cisco Systems, Inc.
NNTP-Posting-Host: regal.cisco.com
In-reply-to: jimc@tau-ceti.isc-br.com's message of 3 Nov 92 22:25:31 GMT

Just for kicks, here are some PAL equations to implement a very flexible
chaser light thing using a 16r8 PAL (be sure and use the really fast 7.5nS
version of the PAL for fastest blinking :-)  (Note, nearly all the other
solutions describe are probably cheaper, easier to get parts for, and easier
to implement.  This one does do more different patterns though...)

ed ecTITLE		LED BLINKER SHIFTER THINGY
PATTERN		SHIFTER.PDS
REVISION	1
AUTHOR		Bill Westfield
COMPANY		Nuts and Bolts Software
DATE		1/19/89

CHIP		U1 PAL16R8
; Pins:
	CK    /ROT  /CMP8 /CMP6 /CMP4 /CMP2 /I6   /I7    INIT GND
	/OE   /Q1   /Q2   /Q3   /Q4   /Q5   /Q6   /Q7   /Q8   VCC

EQUATIONS

Q1 := Q8 * ROT		; maybe shift in MSB for rotate
    + /Q8 * CMP8	; Shift in complement of msb (alternating 1s and 0s)
    + /Q6 * CMP6	; other patterns based on complementing some bit
    + /Q4 * CMP4
    + /Q2 * CMP2
    + INIT
    + /Q1 * /Q2 * /Q3 * /Q4 * /Q5 * /Q6 * /Q7 * /Q8	; always supply 1 bit

Q2 := Q1 			; Shift Left
    + INIT

Q3 := Q2 			; Shift Left
    + INIT

Q4 := Q3 			; Shift Left
    + INIT

Q5 := Q4 			; Shift Left
    + INIT

Q6 := Q5 			; Shift Left
    + INIT

Q7 := Q6 			; Shift Left
    + INIT

Q8 := Q7			; shift Left
    + INIT

SIMULATION

PRLDF /Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8
SETF ROT /CMP8 /CMP6 /CMP4 /CMP2 /INIT
TRACE_ON INIT /Q1 /Q2 /Q3 /Q4 /Q5 /Q6 /Q7 /Q8 
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK

SETF ROT /CMP8 /CMP6 /CMP4 /CMP2 INIT
CLOCKF CK
SETF /ROT CMP8 /CMP6 /CMP4 /CMP2 /INIT
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK

SETF ROT /CMP8 /CMP6 /CMP4 /CMP2 INIT
CLOCKF CK
SETF /ROT /CMP8 CMP6 /CMP4 /CMP2 /INIT
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK

SETF ROT /CMP8 /CMP6 /CMP4 /CMP2 INIT
CLOCKF CK
SETF /ROT /CMP8 /CMP6 CMP4 /CMP2 /INIT
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK

SETF ROT /CMP8 /CMP6 /CMP4 /CMP2 INIT
CLOCKF CK
SETF /ROT /CMP8 /CMP6 /CMP4 CMP2 /INIT
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK
CLOCKF CK

TRACE_OFF
From: Martin_G_Rowland@cup.portal.com
Newsgroups: sci.electronics
Subject: Part needed
Date: Fri,  6 Nov 92 00:31:26 PDT
Organization: The Portal System (TM)
Distribution: ca

I am posting this for a friend of mine.  Please send replys to 

Martin g. rowland@portal.cup.com

[20] From: Eric Michelsen 11/4/92 4:00PM (384 bytes: 4 ln)
To: Martin Rowland
Subject: Voltage Comparator
------------------------------- Message Contents ------------------------------
-
I'm looking for a voltage comparator that runs on +5V, and Gnd power supply,
has TTL compatible output, and allows input voltage ranges of +/- 10V.  Most
Voltage regulators limit the input voltage range to (V-)+1.5V and (V+)-1.5V.
-eric
 
Newsgroups: sci.electronics
From: ch@eiaut2.tuwien.ac.at (Christian Kral)
Subject: Re: 27512-->27128
Organization: Technical University Vienna, AUSTRIA
Date: Tue, 10 Nov 1992 10:49:26 GMT


In article <1992Nov6.200357.20735@ryn.mro4.dec.com>,
klimasewski@fccvde.enet.dec.com (My name is...) writes:
|> 
|> Can I convert a 27512 to a 27128 by lifting a pin from the circuit
|> and
|> bring it to ground? I did this with a 27256 by lifting pin 27 and
|> then
|> grounding it via pin 14.
|> 
|> 
|>                                Ken 

Hi Ken,
the differences between 'em are:

pin  27512        27128
 1     A15         Vpp
 20    !CE/!PGM    !CE
 22    !OE/Vpp     !OE
 27    A14         !PGM

The "!" stands for the low active function of the pin.

What you have to do is to leave out pin 1 and 27 of the 27512 and tie
them to GND (if you want to address the lowest page of the 27512, which
is normally done). Then it will work as the smaller one did.

Good luck,

Christian.
From: prob@btmp24.be (Pascal Roobrouck SH53)
Newsgroups: sci.electronics
Subject: Toxic Copper
Date: 10 Nov 92 14:14:57 GMT
Reply-To: prob@btmp24.be (Pascal Roobrouck SH53)
Organization: Alcatel Bell Telephone, Antwerpen, Belgium


Many articles discuss the possible dangers of using Berillium. However
much more likely to me is the risk of getting poisoned with CuO, the
most frequently used conductor in electronics. If you have Cu, and there
is oxigen in the air or in the water, isn't there a good chance to get
CuO ??

I am particularly interested because I use an 'electronic` sterilizer
for my swimming pool. A current through a pair of underwater copper
electrodes, dissolves Cu-ions into the water. There they form Cu(OH)2
that sterilizes the water (no chlore needed anymore). Is there no danger
with this method. Couldn't get an answer from a chemist yet !


Greetings from Belgium

Pascal Roobrouck

E-Mail prob@sh.alcbel.be
Newsgroups: sci.electronics,sci.physics,news.admin.misc