HDTenEightyP/NetNews huggingface dataset:
From: pieterh@sci.kun.nl (Peter Herweijer)
Subject: Re: "1-bit DAC"
Organization: University of Nijmegen, The Netherlands
Date: Fri, 8 Jan 1993 13:28:13 GMT

In <1993Jan7.235144.15771@clsi.COM> kevin@clsi.COM (Kevin Cameron) writes:

>In article <C0F8Hp.84n@ve7frg.ampr.org>, doug@ve7frg.ampr.org (Doug Collinge - VE7GNU) writes:
>> 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?

	[explanation deleted]

>I'm not sure what scheme the "1 bit DAC" actually uses, but the implication is
>that you would need 256 times over-sampling for 8bits. 

Mostly right, but let me put in my $0.02:

in order to produce an average DC signal of 1/256 part of maximum, an
1-bit DAC produces 255 0's to every 1.  For a 'dumb' 1-bit DAC, this
would imply that in order to get 8-bit resolution, 256 times oversampling
is required; for 16-bit resolution, 65536 times oversampling.

However audio signals are never static (except when silent). By making
the place where the 1's and the 0's are put, corresponding to one input
sample, dependent on the shape of the input as a whole, it is possible
to produce a more accurate result using the same oversampling rate
(excuse me for my rather clumsy way of putting this). This is achieved
at the cost of a very chaotic behaviour of small trains of 0's and 1's,
as you can imagine. The net effect is that the quantisation noise 
( = DAC error) is moved from low frequencies (the audio band) to high
frequencies (just below the oversampling frequency where they can be
easily filtered out). Hence the term "noise shaping".

The simplest (first order) noise shaping algorithm goes like this:

    error := 0
    loop begin
        data := sample                          { 0<sample<1 }
        for n:= 1 to oversampling_rate begin
            output := round(data + error)       { round(x) = 0 if x<0.5  }
            error  := error + data - output     {            1 otherwise }
        end
    end

The error made by converting the input to 1 bit is carried over to the
next sample, etc.  For, say, a DC level of 1/256, this noise shaper would
behave just as a 'dumb' 1-bit DAC, and a tone of 1/256 the sampling
frequency would be audible, but for real world signals this performs
much better. For large oversampling rates, by the way, this simple
algorithm breaks down and higher-order algorithms are needed.

This is about all I know about it. If someone out there can tell what
the theoretical S/N ratio for this scheme is, and how higher-order noise
shaping algorithms work: I, for one, would be interested to hear!

Peter Herweijer
pieterh@sci.kun.nl
Xref: sparky sci.electronics:22035 rec.video:15450
From: ilango@cbnewsd.cb.att.com (thirumalaiswamy.ilango)
Newsgroups: sci.electronics,rec.video
Subject: VCR repair - need help to troubleshoot
Keywords: VCR repair
Date: 5 Jan 93 23:33:00 GMT
Followup-To: poster
Distribution: na
Organization: AT&T


Hello,
Any idea why my 5 year old VCR (Panasonic) is not playing
videos recorded in SLP or very old videos. The image is very shaky (like when 
the vertical hold button is not adjusted) and no audio is heard. Also sometimes the VCR display changes in quickly from LP to SLP and back to LP (when a 
video recorded in SLP is played).
The VCR plays a new cassette or a cassete recorded in SP well. I have tried 
the head cleaner already. Please send me email. Thanks. 

Ilango
ilango@cbnewsd.att.com
att!cbnewsd.att.com!ilango
From: kludge@grissom.larc.nasa.gov (Scott Dorsey)
Newsgroups: sci.electronics
Subject: Re: HDTV Question
Date: 8 Jan 1993 16:40:00 GMT
Organization: NASA Langley Research Center and Reptile Farm
NNTP-Posting-Host: grissom.larc.nasa.gov

In article <1993Jan8.055618.24902@mtu.edu> cmwolf@mtu.edu (christopher m. wolf) writes:
>If HDTV will be digital, what will be the number of available colors for
>display?

Depends on the format that is decided on.

>Instead of the "infinite" we have with NTSC now, this will have to be reduced,
>depending on the digitalization, but what are we talking about numbers-wise?

Infinite colors?  With NTSC?  You have to be joking... the linearity of the
chrominance signal is terrible on any NTSC systems.  The number of discrete,
distinguisable colors is far fewer than those that can be seen by the eye,
or even recorded on a good film.
--scott
From: astrachan@austlcm.sps.mot.com (Paul Astrachan)
Newsgroups: sci.electronics
Subject: Yamaha IC in Soundblaster/Adlib
Date: 7 Jan 93 16:30:24 GMT
Reply-To: astrachan@austlcm.sps.mot.com (Paul Astrachan)
Organization: Motorola MOS Telecom

Does anyone know where to buy the Yamaha YM3812 (FM chip) in the soundblaster?

Paul Astrachan
Motorola Telecom 
astrachan@austlcm.sps.mot.com
Xref: sparky sci.electronics:22134 alt.cd-rom:5491
From: dplatt@ntg.com (Dave Platt)
Newsgroups: sci.electronics,alt.cd-rom
Subject: Re: chip vendor databooks/sheets/applic notes
Date: 6 Jan 93 22:06:40 GMT
Organization: New Technologies Group, Inc.  Palo Alto CA

>people like me who cant really justify or squeeze out of sales people
>sets of databooks wouldnt mind paying a 20-50$ for a CD-ROM.
>
>my particular fascination this week is with MAXIM, EXAR and Motorola chips.
>
>but i would be interested in hearing of any vendor/brand making CD-ROMs
>available.

The only one I have any experience with at the moment is the CAPS system
being distributed by Cahners Publications.  It's a big library (two
index CDs and a library of about 45 databook CDs) which covers most of
the ICs in the industry.  Their retrieval software will let you search
the index of parts for any which meet specific criteria (e.g. all
DIP-footprint GALs with at least 13 inputs, 7 outputs, 3.3-volt
operation, and 2 nS propagation time ;-).  You can retrieve the
databook pages (scanned-in from the databooks), view them at several
magnifications, and print them.

Not an inexpensive solution.  The discs are licensed, not purchased - a
one-year license for the library and software costs almost $10,000.  You
can either lease the hardware (a loaded 386 with at least two CD-ROM
drives) or buy your own.  Updates come out monthly - two new index
discs, plus one or more new discs for the library.  New-part listings
seem to run 6 months to a year behind manufacturer announcement-and-
publication.

It seemed to work reasonably well in the demo I saw, although the
retrieval software and information-index could use some additional work.
I have my doubts as to whether it'd be cost-effective for any company
having less than 50 engineers, though.

I urged the Cahners rep I spoke with to consider setting up some sort of
per-hour-charge on-line retrieval service, to make the system's
capabilities available to individuals and smaller companies which can't
afford a $15k investment.

-- 
Dave Platt                                                VOICE: (415) 813-8917
              Domain: dplatt@ntg.com      UUCP: ...netcomsv!ntg!dplatt
 USNAIL: New Technologies Group Inc. 2470 Embarcardero Way, Palo Alto CA 94303
Newsgroups: sci.electronics
From: sdavis@laforge.ksc.nasa.gov (Steve Davis)
Subject: Re: Destroying Xilinx FPGAs by improper configuration?
Organization: NASA
Date: Tue, 12 Jan 1993 19:11:48 GMT


  While we're on the subject, are there any newsgroups or mailing lists devoted  
to FPGA design?  Also, does anyone know if Xilinx has an internet email  
address?

Regards,

Steve
--
+----------------------------------------------------------------+
| Steve Davis                      | sdavis@laforge.ksc.nasa.gov |
| NASA, DL-DSD-32                  |    (NeXT Mail OK)           |
| Kennedy Space Center, FL  32899  | HSSC Mail:  RDAVIS          |
| (407)867-7582  fax:(407)867-2173 | #include <disclaimer.h>     |
+----------------------------------------------------------------+
Newsgroups: sci.electronics
From: wrb@cbnews.cb.att.com (wallace.r.blackburn)
Subject: Re: Magnetic Sensor?
Organization: AT&T
Distribution: usa
Date: Mon, 4 Jan 1993 14:42:19 GMT

In article <1993Jan2.104609.4196@arizona.edu> dparker@ece.arizona.edu (Douglas R. Parker) writes:
>Greetings.
>
>Quite a while back I attempted to repair the tape deck
>in my Toyota. I found that one of the plastic shafts that
>rotates the casette's tape wheel had cracked, leaving a gap
>in the gear teeth. I assume the reason for malfunction and
>subsequent devouring of many a tape was a perpetual End of
>Tape being recieved. I tried using similar salvage parts to
>replace the gear but this didn't work. The reason for this,
>I think, is that the original gear had a small disk magnet
>fixed to its base, and beneath it was a small surface mount
>component. I assume this is some sort of a tape speed
>regulation. My question? The matter is rather academic at this
>point, as this was a good excuse to buy a CD unit. However,
>I am still very curious as to how the thing worked. Although
>my EMAG is rusty, I would guess that a rotating B field was
>somehow used to induce current in this sensor, which was
>then used as a feedback. Does anyone out there have experience
>with this type of arrangement?
>Just extremely curious,
>
>dparker@helios.ece.arizona.edu
>
> 

Good chance that it is (was) simply a Hall effect sensor.  A micro in the
deck used the square wave from the sensor to control the speed.

I don't pretend to know the physics behind it, but a Hall effect sensor is,
in effect, a magnet-controlled switch.  Hysteresis makes the output kind of
"spongy", though.
From: mike-d@staff.tc.umn.edu (Mike Diack)
Newsgroups: sci.electronics
Subject: Re: CCD analog shift register?
Date: 12 Jan 93 15:11:08 GMT
Article-I.D.: news2.C0qy6n.LoA
Organization: persian cat & carpet co.
X-Xxdate: Wed, 13 Jan 93 04:19:09 GMT
X-Useragent: Nuntius v1.1.1d7

In article <DEVON.93Jan9001145@digex.digex.com> Devon Sean McCullough,
devon@digex.digex.com writes:
>Where can I get an analog shift register?  It's not in any catalog I
>have seen.  I want to hack up a gadget to slurp up part of a video
>scan line and spit it out more slowly a little later.

Reticon make a range of these devices 
345 Potero Av
Sunnyvale, CA 94086
(408)738-4266
I have used their analog CCDs for audio (in the days before DACs
ADCs & RAMs) and they worked OK - recall they had wads of video
optimised devices. Wattcha building - a standards converter ?
cheers,
	Mike.
Newsgroups: sci.electronics
Subject: MC68HC16 ToolKit Filter Coeffs???
From: unitelmc@otago.ac.nz
Date: 11 Jan 93 15:30:21 +1300
Organization: University of Otago, Dunedin, New Zealand

Has anyone done the Tutorial with the Motorola 'HC16 Development kit
(MC68HC16TK). If you have, could you send me the coefficients you used in the
filter routines? My calculations come out all wonky when I run the program.
Email to me direct, please!

Michael Croot                   UNITELMC@OTAGO.AC.NZ
University of Otago
Dunedin, New Zealand

Newsgroups: sci.electronics
From: masterov@chiller.ecn.purdue.edu (Michael Masterov)
Subject: Re: to the guy looking for 33K uF caps
Keywords: amp
Organization: Purdue University Engineering Computer Network
Date: Sat, 9 Jan 1993 01:23:00 GMT

In article <1339@blue.cis.pitt.edu> karol+@pitt.edu (Filip M. Gieszczykiewicz (fmgst+@pitt.edu)) writes:
>
>	Greetings. If you're not looking for large caps, hit "n" now.
>
>	Give MECI a call at 1-800-344-4465 and ask about part # 191-1894F
>	It's a 30,000 uF electrolytic with 60V rating. These are "Computer
>	Grade" whatever that means. The price is $17.02 each or $8.51
>	for 5+
>
>	If you want to OVERKILL, ask about part # 192-0218F which is rated
>	for 75VDC and has a comfortable 230,000 uF capacitance! You pay
>	for it, though, $37.56 or $18.78 for 5+
>
>	Hope this helps. In case you need more than 75V you can always
>	put 2 of the above in (let me see) parallel (me thinks).
>
>	Take care.
Caps go in series to increase voltage rating, in parallel to increase 
capacitance rating!
Hope you did not have an explosion....

M
From: etxansk@garbo.ericsson.se
Newsgroups: sci.electronics
Subject: ASICs - what can you do with'em?
Date: 5 Jan 93 15:20:08 GMT
Organization: Ericsson
Originator: etxansk@garbod26


 I've read a little in magazines about ASICs. Since I'm only involved in
software engineering at work, it's sometimes hard for me to tell the 
limitations of a certain technique by reading summaries etc.

 So, what can be done with ASICs?

 Is it possible to create more than just plain Y=f(X) logic with
ASICs? Plain logic would probably be enough for doing a simple
MMU or anything similar, but can something that involves (for instance) 
counters be implemented? Would it be possible to design a circuit that 
creates (video) hsync and vsync from a clock input with one single ASIC?

 Are there other techniques that provide affordable single-chip custom 
design for the man on the street?

 Thanks in advance,
 Anders Skelander
From: thomas@bit.UUCP (Thomas Walter)
Newsgroups: sci.electronics
Subject: source of 80515 or 80517 uC in small quanities?
Date: 11 Jan 93 20:11:54 GMT
Article-I.D.: bit.549
Organization: BIT, Portland, OR



Does anyone know of any (small quanity) sources for either:

	80515   Siemans microcontroller
	80517	Signectics microcontroller

	These are based on the 8031 type controllers,
        with additional ports/timers/built in ADC etc.

	Just looking for a source of SMALL quanities of
	(2 to 20) these chips.

	[Yes, I've heard lead times have gone from 12 to
	46 weeks on some of these devices!]

Thanks,

Tom Walter				bit!thomas@cse.ogi.edu
From: root@fangorn.hacktic.nl (Root Account)
Newsgroups: sci.electronics
Subject: Re: Replacement IR Remote Controls
Date: Tue, 12 Jan 93 00:07:48 GMT
Organization: Fangorn System

etxansk@garbo writes:

>  Does anyone know if different Philips IR remote controls from the
> 80's with "text" functions use similar IR signals and message
> encoding techniques?

Yep. All those philips things use the RC5 remote control system, which was 
developped by philips. have used it for about forever... So philips remotes 
that are for the same machine (i.e. TV remotes, VCR remotes, CD player 
remotes) are interchangeble. I tested this myself with a <1980 remote and a 
1987 VCR. Works just fine. Also, if there's anything wrong, my local Philips 
Service Centre just sells some universal remote control... No known problems.

>  Also, I've seen that there are IR controls available that can record
> other IR controls' signals and keep the function set of many different
> controls in them. Is it likely that such an all-round control with the
> ability to "learn" new signals will be able to record our old device's
> signal?

Yeah, sure. Those things just sample the IR and record it. So if it says 
that it can record all other remote signals, it most probably will.... And 
the philips system is a very widely used one, so almost everything 
"universal" will be compatible.... 

hope this helps,

bram smits
From: wouter@blade.stack.urc.tue.nl (Wouter Slegers)
Newsgroups: sci.electronics
Subject: Info on Voice stress analysers wanted
Date: 5 Jan 93 11:40:41 GMT
Organization: MCGV Stack, Eindhoven University of Technology, the Netherlands.
X-Newsreader: TIN [version 1.1 PL6]


I heard of these voice-stress-analysers that are suppost to be able to
detect the amount of stress by the sound... How is this done?? Does Anyone
have a pointer to some info?? 

Please post or (preferebly) email me...
Wouter Slegers
(wouter@stack.urc.tue.nl)

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 (   ).(   )     (Neue Regel, Queensryche)         |
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      |     Ash nazg durbatuluk, ash naszg gimbatul, ash nazg thrakatuluk,
      |      agh burzum-ishi krimpatul (Lord of the Rings, J.R.R. Tolkien)
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Newsgroups: sci.electronics
From: fossey@progress.COM (Paul Fossey)
Subject: X10 Control Interface
Summary: Interface specifications ?
Keywords: X10
Organization: Progress Software Corp.
Date: Thu, 7 Jan 1993 14:44:00 GMT

I recently purchased an 'X10' home control interface for my PC. This box is
connected to an RS-232 port, and is able to control light and appliances
throughout the house. The control modules are sold by 'X10', Stanley, and
Radio Shack. 

I want to build some custom control modules. Has anyone ever seen specs on the
signals sent over the house wiring for these modules ?


Newsgroups: sci.electronics
From: gvm@nemesys.demon.co.uk (Granville Moore)
ReplyTo: gvm@nemesys.demon.co.uk
Subject: Re: VCR Recording Problems
Distribution: world
X-Mailer: cppnews $Revision: 1.19 $
Organization: Dis-organisation
Date: Mon, 4 Jan 1993 19:40:31 +0000


In article <78979@hydra.gatech.EDU> np4@prism.gatech.EDU (Nick Pomponio) writes:

> I have a Panasonic 4-head VCR that is about 8 years old.  It is a "portable"
> (read "luggable") unit that can record from a separate camera. Lately, any
> time I record from the camera, the image is "noisy" when played back - it
> looks like the tracking needs to be adjusted, but doing so doesn't help.
> Prerecorded videos work just fine. Any help in diagnosing the cause of this
> problem would be greatly appreciated.
> 

Do you notice any odd effects if you use a "slow motion replay" mode?  Any
differences in SP/LP modes?

From the description, I guess that this could be one of many problems, but
since it's a Panasonic 4-head, it *could* be related to the problems that
I've been having with my (rather more recent, but probably closely-related)
Panasonic NV-FS90B.

I bought it 6 months ago, and after 3 months it started to give noisy playback,
similar to your description, but only on SP.  When I put it into SP "slow
motion replay", alternate frames are good, and bad (heavy noise, much worse
than that seen in normal play).  This looked to me like a single head failure,
and the shop's repairer (on the 2nd attempt), replaced (under guarantee)
the drum assembly.  4 weeks later (a few days ago) it failed again.  I feel
rather pessimistic about another head assembly (this seems unlikely to
work and, even if it does, how long after the guarantee period is it likely
to last?).

I would be really tempted to take this thing apart and take a look myself,
but, of course, that would invalidate the guarantee (for what it's worth!).

I bought Panasonic because of their reputation for reliability, and it was
an "upgrade" for an 5-year-old Panasonic NV-G12 that has given good service.
On the whole, I'm not really impressed with the FS90B - it cost twice as
much (700 UK Pounds - discounted from 850), its ergonomics are poorly
thought out, performance about the same as the G12 (when new) and it is
(to say the least) rather unreliable.  Panasonic - here goes your reputation...

I'll let you know if I get any more information that might be useful to you.
Meanwhile, if anyone has any suggestions about my machine, to quote the
immortal words of Spock: "I am all ears"...

Regards,

Granville

------------------------------------------------------------------------
Warning: signature file under construction - read carefully
Granville Moore                                  gvm@nemesys.demon.co.uk
------------------------------------------------------------------------
Newsgroups: sci.electronics
From: s3176997@techst02.technion.ac.il (Daphne Rosenhouse)
Subject: PIXAR
Organization: Technion, Israel Institute of Technology
Date: Tue, 5 Jan 1993 22:57:11 GMT

hi all
i heard alot about PIXAR
i have no idea what it is !
can anyone explain please ?
thx

Newsgroups: sci.electronics
From: jecome01@vulcan.spd.louisville.edu (Eric Comer)
Subject: telephone ringer voltage
Date: Wed, 6 Jan 1993 17:30:29 GMT
Organization: University of Louisville

I was wondering if anyone knew the voltage that is sent on the ringer
line of a telephone cable when a call is incoming.  any help would be
greatly appreciated.

-- 

--------------------------------------------------------------------------------

Eric Comer                               PHONE: (502)588-5090 or (502)588-7620
University of Louisville                 FAX:   (502)588-8890
Speed Scientific School                  E-Mail Internet:     
Electrical Engineering                    jecome01@starbase.spd.louisville.edu
                                         E-Mail Bitnet:
			                  jecome01@ulkyvx.bitnet

--------------------------------------------------------------------------------
From: paula@nlbbs.UUCP (Paula Stockholm)
Newsgroups: sci.electronics
Subject: How to calculate crystal freq for scanner?
Date: Wed, 06 Jan 93 18:43:19 GMT
Reply-To: paula@nlbbs.uucp
Distribution: world
Organization: The Electronics Workbench - Cumberland Maine

        Just one quick note to follow the excellent response about
        scanner crystals - Bearcats are different! They use an IF of
        10.8 MHz.

        * * * * * * * * * * * * * *  * * * * * * * * * * * * * * *
        *    Paula Stockholm             paula@nlbbs.UUCP        *
        * The Electronics Workbench       (207) 829-3152         *
        *   Cumberland, Maine         !nlbbs!paula@uunet.uu.net  *
        * * *  * * * * * * * * * * * * * * * * * * * * * * * * * *
From: sl@nessie.mcc.ac.uk (Stuart Lea)
Newsgroups: sci.electronics
Subject: PLease help - video playing up !
Date: 7 Jan 93 17:02:00 GMT
Organization: Manchester Computing Centre


Video will not review (ie rewind whilst seeing what's on the screen) it just
freeze frames then stops after about 4 seconds. I guess that the end of tape 
detector cuts in as the tape is not working.

It also gets very wobbly towards the end of a tape. The sound has a wonderful
vibrato effect :<, and noise bars appear on the screen.

Is this simple to fix ? Is the motor trying to tell me that it's soon going
on an extended holiday to motor heaven ?

Thanks in advance,

Stuart

-- 
+Stuart Lea---Tel:061 200 4809--Fax:061 200 4019---UMIST University-----------+
| JANET   :   sl@uk.ac.mcc.nessie                  B22, Main Bldg., PO Box 88 |
| INTERNET:   sl@nessie.mcc.ac.uk                  Manchester, UK M60 1QD     |
|                 "Weather is here, wish you were beautiful"                  |
Newsgroups: sci.electronics
From: cseb@frodo.lfi.uni-hannover.de (Christian Sebeke)
Subject:   Speaker Simulators  (Electric Guitar)
Reply-To: cseb@frodo.lfi.uni-hannover.de
Organization: Univ. Hannover, LFI, Abt. Design&Test
Date: Tue, 12 Jan 1993 08:36:46 GMT

Hello.

   I wonder if there is someone who has the scematics for the
"speaker simulation" circuits used in guitar effect boxes (e.g. Zoom),
preamps (Marshall JMP-1), DI Boxes (H&K Red Box) or Power soaks
(Marshall SE100). Any hint would be appreciated.

---

Christian Sebeke, Univ. Hannover/LFI, Schneiderberg 32, D-3000 Hannover 1                             Tel: +49 511 762 5035                    sebeke@frodo.lfi.uni-hannover.de