Chip with simple program for Toy

[petrus bitbyter]

"Peter Andersen" <peter@invalid.invalid> schreef in bericht
news:dla8rp$qin$1@news.net.uni-c.dk...

Hi,

I am trying to capture an input with a status pin on the standard IBM
parallel port.

I looks like all the status pins are set high default when there's no
external voltage source connected.
If I measure the voltage drop across pin 13 (status 4) and pin 25 (ground)
I get 5,1 V. Shouldn't it be zero?

I am using FreeBSD and if I read the value of the status pins with nothing
connected I get
Status: 0x7f
Nothing happens if I connect a 5 V voltage source to pin 13 and pin 25.

If I short circuit pin 13 and pin 25 I get
Status: 0x6f

Isn't it supposed to be the other way around or am I doing something
wrong?

Best regards.

Guess you'd better enlarge your knowledge about the parallel port interface.
One place - amongst others - is:
http://www.beyondlogic.org/
It lacks hardware details. Some more can be found at:
http://www.epanorama.net/circuits/parallel_output.html

Although pin description and register usage are well defined, hardware
details of the inner port are not very common. One of the reasons may be
that since the times of the first PC manufacturers used a variation of
components to implement its funcion. An average printerports hardware was
build like this:
- The datalines were TTL-outputs like LS273 or LS374. Some had smal
seriesresistors in the outputlines like 22E or 33E (E for Ohm). A capacitor
of about 470pF to GND was common although I often saw its space on the board
left empty.
- The controllines used open collector outputs like LS06 or LS07. The had
pullup resistors of let's say 4k7 and also capacitors to GND.
- The statuslines had LS14 Schmidtriggered inverters for input and low
(150E) pullup resistors. Place for capacitors was often available but left
empty.

It did not take long before special I/O chips took over the role of the
common TTL-components but the function was assumed to remain the same. I did
not always fit. I remember a parallelport chip build in CMOS that was blown
whenever the PC was switched off before the printer was. Nevertheless a
common parallel printerport will still be able to provide (about) the same
performance the old things did.

petrus bitbyter

 

[Winfield Hill]

GregS wrote...

OPA134 for a traditional OP-AMP. Single version.Think of it
as a really beefed up TLO81. Power bypass caps are necessary
for high speed amps.

I don't like getting into bed with an opamp with no schematic.


--
Thanks,
- Win

 

[David Maynard]

Mxsmanic wrote:

David Maynard writes:


Saying they're 'dense' is a bit harsh and you're basing it on the culture
you're used to. I mean, if everything you saw was a picture of what's
inside then you'd probably expect the picture to be a picture of what's
inside too.


But I would still realize that a picture of, say, a mountain on the
label would not mean that a mountain was contained inside the jar.

Maybe mountain dirt. You hear people say "he could sell snowballs to an
eskimo" so I guess someone could sell mountain dirt too

While I can understand that they might be accustomed to having a
picture on the jar that shows what's inside, I also credit them with
enough reasoning ability to realize that an actual baby isn't going to
be crammed into the jar just because a picture of one is on the label.

I don't know why. We got lunatics in this supposedly 'educated' country
claming we rammed planes into our own trade towers, or blew them up.

It reminds me, though, of the famous story of the illiterate woman (in
the U.S.) who bought a gallon can of Crisco because she thought it had
a roast chicken inside (there was a picture of a roast chicken on the
label).

Seems you just disproved your own point

Actually, the point isn't whether everyone thought it had a baby inside but
that any confusion at all isn't conducive to selling the product and
neither is dismissing it as them being dense. Even if you're right it don't
get the jars sold

 

[Peter Andersen]

Thanks for all the replies. They were all very helpful.

 

[Rich Grise]

On Mon, 14 Nov 2005 16:00:15 +0100, Peter Andersen wrote:

I am trying to capture an input with a status pin on the standard IBM
parallel port.

I looks like all the status pins are set high default when there's no
external voltage source connected.
If I measure the voltage drop across pin 13 (status 4) and pin 25 (ground) I
get 5,1 V. Shouldn't it be zero?

I am using FreeBSD and if I read the value of the status pins with nothing
connected I get
Status: 0x7f
Nothing happens if I connect a 5 V voltage source to pin 13 and pin 25.

If I short circuit pin 13 and pin 25 I get
Status: 0x6f

Isn't it supposed to be the other way around or am I doing something wrong?

Actually, that sounds about right - they're pulled up internally, so you
have to pull them low to get a 0:
http://www.epanorama.net/documents/pc/parallelport_schematic.html

Have Fun!
Rich

 

[Jasen Betts]

On 2005-11-14, Peter Andersen <peter@invalid.invalid> wrote:

Hi,

I am trying to capture an input with a status pin on the standard IBM
parallel port.

If I short circuit pin 13 and pin 25 I get
Status: 0x6f

Isn't it supposed to be the other way around or am I doing something wrong?

you're doing it right.the pins are high by default, you need to connect the
pins to ground to change their status.

If you want it to be the other way round you can connect them to ground
using a 1K resistor and then they'd be low by default and applying +5v
would change thier state.


Bye.
Jasen

 

[David Maynard]

clifto wrote:

Mxsmanic wrote:

David Maynard writes:

Except for spammers that routinely post years, even decades, into the past.

What's the advantage of doing so? And why can't servers simply reject
anything that is obviously far in the past?


Most MUAs sort by date ascending. That puts their spam right at the top
of the list.

I suspected it was something like that but I sort by date descending so
they're not only at the bottom but off the screen entirely most of the time.

 

[Mxsmanic]

clifto writes:

Most MUAs sort by date ascending. That puts their spam right at the top
of the list.

Do they? I always have all my messages sorted with the most recent
first. I don't remember what the default is. It seems odd to put
most recent last, since that would require constant scrolling downward
to see the latest messages.

--
Transpose mxsmanic and gmail to reach me by e-mail.

 

[Peter Hucker]

On Sat, 19 Nov 2005 16:03:41 -0000, Fred Abse <excretatauris@cerebrumconfus.it> wrote:

On Sun, 13 Nov 2005 21:44:31 -0600, David Maynard wrote:

Mxsmanic wrote:

Michael A. Terrell writes:


Anthony Fremont wrote:

IBM completely killed off Honeywell and Burroughs with good marketing
skills, not better hardware. The competition lay in salesmanship and
brainwashing, not making better stuff or even trying to be cost
competitive.


IBM killed off Burroughs? What are you talking about? Burroughs
merged with Sperry in 1986 and still operate under their new name,
Unisys.


IBM didn't kill off Honeywell, either. Honeywell bought GE's computer
division, then Bull SA (the French computer company) bought Honewell's
computer division. Today it survives as Bull SA (the unfortunate name
of the company comes from Fredrik Bull, the Norwegian founder of a
company that ultimately evolved to Bull SA today).


Well, that's a lot of Bull

I'm still waiting for Bull and Siemens to set up a joint AI venture

Where is the start of this thread? I typed "Why aren't computer clocks as accurate as cheap quartz watches?" into google groups and it didn't find anything.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

A lot of folks can't understand how we came to have an oil shortage here in America.
Well, there's a very simple answer......Nobody bothered to check the oil. We just didn't know we were getting low.
The reason for that is purely geographical. Our oil is in Alaska, Texas, California, and Oklahoma.
Our dipsticks are in Washington DC.

 

[w_tom]

do_not_spam_me@my-deja.com started this thread on 26 Oct
2005 with this simple question:

Why do the battery powered clocks in personal computers tend
to keep worse time than quartz watches, even the $1 ones?
Staying on topic has been a problem here.

Peter Hucker wrote:

Where is the start of this thread? I typed "Why aren't computer
clocks as accurate as cheap quartz watches?" into google groups
and it didn't find anything.

 

[Peter Hucker]

On Sat, 19 Nov 2005 20:42:11 -0000, w_tom <w_tom1@hotmail.com> wrote:

do_not_spam_me@my-deja.com started this thread on 26 Oct
2005 with this simple question:
Why do the battery powered clocks in personal computers tend
to keep worse time than quartz watches, even the $1 ones?

I see. Found it now. I askjed because I'd asked this very same question years ago and had forgotten the answer.

Staying on topic has been a problem here.

And in every group with more than 2 people. It's human nature.

Peter Hucker wrote:
Where is the start of this thread? I typed "Why aren't computer
clocks as accurate as cheap quartz watches?" into google groups
and it didn't find anything.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

Computer possessed? Try DEVICE=C:\EXOR.SYS

 

[David Maynard]

Fred Abse wrote:

On Sun, 13 Nov 2005 21:44:31 -0600, David Maynard wrote:


Mxsmanic wrote:


Michael A. Terrell writes:



Anthony Fremont wrote:


IBM completely killed off Honeywell and Burroughs with good marketing
skills, not better hardware. The competition lay in salesmanship and
brainwashing, not making better stuff or even trying to be cost
competitive.


IBM killed off Burroughs? What are you talking about? Burroughs
merged with Sperry in 1986 and still operate under their new name,
Unisys.


IBM didn't kill off Honeywell, either. Honeywell bought GE's computer
division, then Bull SA (the French computer company) bought Honewell's
computer division. Today it survives as Bull SA (the unfortunate name
of the company comes from Fredrik Bull, the Norwegian founder of a
company that ultimately evolved to Bull SA today).



Well, that's a lot of Bull


I'm still waiting for Bull and Siemens to set up a joint AI venture

Now there's a combo that, like the breakup of Ma Bell, is sure to spin off
a bunch of 'baby bulls'.

 

[w_tom]

Peter Hucker wrote:

On Sat, 19 Nov 2005 20:42:11 -0000, w_tom <w_tom1@hotmail.com> wrote:
Staying on topic has been a problem here.

And in every group with more than 2 people. It's human nature.

And this has been an extremely human discussion.

 

[Peter Hucker]

On Sun, 20 Nov 2005 08:59:50 -0000, w_tom <w_tom1@hotmail.com> wrote:

Peter Hucker wrote:
On Sat, 19 Nov 2005 20:42:11 -0000, w_tom <w_tom1@hotmail.com> wrote:
Staying on topic has been a problem here.

And in every group with more than 2 people. It's human nature.

And this has been an extremely human discussion.

Whaddaya mean? [not having read much of the diussion after it went off topic]


--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

What happens if you install windows 98 on a system with 2 processors?
It crashes twice.

 

[David Maynard]

Fred Abse wrote:

On Sat, 19 Nov 2005 19:16:18 -0600, David Maynard wrote:

snip

the GUI *was* the (second
half) of the 'big idea' that made Microsoft what it is


Invented at Xerox PARC

Introduced to the market by Apple

You came to the discussion late. The 'big idea' we speak of is context
specific and refers to Microsoft making Windows for the purpose of running
their Apple developed office applications (which is why I refer to it as
the "second half"), not that the GUI concept was their idea.

 

[PeteS]

An 'analog' RAM is sometimes known as a sample and hold, but it doesn't
hold for very long.
Such circuits are usually used in front of an A-D, so the analog value
may be stored as a digital value.

It is possible to make an analog storage cell, but it's far easier to
use an A-D (in general, at least).

Cheers

Petes

 

[Lord Garth]

"Davy" <zhushenli@gmail.com> wrote in message
news:1132561905.494052.44210@z14g2000cwz.googlegroups.com...

Hi all,

We know that digital circuit use RAM and D-FF to store digital signal
values. Is there any "Analog" RAM and D-FF which can store analog
signal values?

I am curious to know if not, how to store analog signal values in
analog way?

Any suggestions will be appreciated!
Best regards,
Davy

That is the heart of the ISD recorder chips....
http://www.winbond-usa.com/mambo/content/view/36/14

 

I use the Ono Sokki. I think it's a 1700 series. I am away from the
clean area right now. But I don't think you can even buy a case for it
at $2000

 

[John Larkin]

On Wed, 23 Nov 2005 20:19:58 +0000, Chris Jones
<lugnut808@nospam.yahoo.com> wrote:

John Larkin wrote:

On Tue, 22 Nov 2005 07:38:30 -0800, "Richard Henry" <rphenry@home.com
wrote:



Or ionizing radiation.



Sure. Xrays were used to erase the original eproms (three or four
times, then the silicon was destroyed.)

A rough calculation suggests the floating gate on the Intersil
reference leaks less than an electron per hour.

John

I wonder if you could use them as dosemeters. I don't have a source of
x-rays to test this possibility, but one of you guys might have an x-ray
machine for inspecting the soldering of BGAs. You could measure the
reference voltage with a good voltmeter before and after exposing the chip.

Chris

Yup, that should work. The classic old pen-type dosimiter was a
charged, bent fiber that straightened out as radiation removed the
charge. It had similar low leakage.

Another good project: use an EPROM as a super-high-resolution deep-UV
or xray imager.

John

 

[Cliff]

"Bill Roberto" <upnrunning@earthlink.net> wrote in message
news:Ba7hf.1357$A23.374@newsread2.news.pas.earthlink.net...
I had to make a communication cable for a customer today. I went to
Orvac's and asked for 100' feet of 4 wire shielded cable. The salesman
said he went to a 3 day wire seminar from Beldon Cable. They claim that
twisted wire will work as good or better than shielded cable. I asked
why and he said that any noise picked up by one wire gets cancelled out
by being wrapped around the other wires. I figured that would probably
be true for any electromagnetic noise but what about RF noise? He didn't
know, so I bought the shielded because I don't want to experiment on a
customer. Has anyone used twisted wire cable for communications?

On Wed, 23 Nov 2005 18:43:47 -0600, "shu" <washu@hiwaay.net> wrote:

Absolutely not

Oh, Goodie <G>.

Unshielded Twisted Pairs cancel noise out, only because each line recieves
equal amount of noise, and Hence at the *Balanced* line RECEIVERS there is
noise cancellation

Delta V = ~0 at about any place on the twisted pairs as a result
of EM noise from the environment, assuming that it's wavelength
is at right angles to the lines and it's wavelengths far larger than
the pair conductor to conductor distance (excluding speed of
light changes<G>.)

the actual noise cancellation occurs AT the receivers,

How did it get there?

and ONLY if they are
balanced on each end... like computer network cables.

??

If your communication cable setup is not balanced at each end, then the
magical noise cancellation disappears, and in fact you'll get quite a bit of
noise.

You could add a rectifier and get free energy, right? Just from
the thermal background noise ...
--
Cliff