Chip with simple program for Toy

[Active8]

On 31 Mar 2005 06:58:09 -0800, SklettTheNewb wrote:

I have been messing with CircuiMaker and doing "spice simulations"
I have also been reading from these different sites:
http://www.kpsec.freeuk.com/ohmslaw.htm
http://www.play-hookey.com/digital/ripple_counter.html
http://www.allaboutcircuits.com/vol_1/chpt_2/index.html

Argghh! I just looked at that third link. That current convention
thing (from menu on the left) is backwards to anything I've ever
seen in circuit analysis texts and will f you up if you pusue
electronics seriously - like Kirschoff's laws and node and mesh
(loop) analysis.

It's this way:

+ V -
___
-|___|-

I -------->

Note that this is the same from the perspective of voltage
generators as opposed to drops. An example might clear this up:

+------------------+
| |
| |
| |
+ | ^ I |
| | | .-. +
--- | | | |
V - | | | | V
| | | '-' -
- | | V |
| I |
| |
| |
+------------------+
|
^ call this the reference node or O V

Kirschoff's Voltage Law (KVL) says that the sum of the voltage drops
around a closed loop equals zero.


Sum(V_i) = 0. or

n
___
\
/__ V_i = 0
i=1

Starting at the negative terminal of the batt, and noting that we're
going with the flow, i.e., current (charge flow), from negative to
positive, we have a negative drop or positive voltage rise. Say the
drop is -9V, i.e. 0 - 9 = -9 You take the starting value and
subtract the ending value.

At the resistor, we're going from positive to negative, which is a
positive drop from 9V to 0v, i.e., 9 - 0 = 9

so -9 + 9 = 0

Another way of stating KVL is that the sum of the generator voltages
is equal to the sum of the voltage drops. So in the same manner,
going from the reference node to the positive terminal of the
battery, we have a positive generator and

9 = 9 which is the same as 9 - 9 = 0 or -9 + 9 = 0

I'd recommend a better site if I knew of one for sure. Maybe that's
the only thing wrong, though.
--
Best Regards,
Mike

 

[Active8]

On 31 Mar 2005 06:58:09 -0800, SklettTheNewb wrote:

I have been messing with CircuiMaker and doing "spice simulations"
I have also been reading from these different sites:
http://www.kpsec.freeuk.com/ohmslaw.htm
http://www.play-hookey.com/digital/ripple_counter.html
http://www.allaboutcircuits.com/vol_1/chpt_2/index.html

I'm slowly getting my head around the current and voltage ideas. I
have encountered a strange situation w/ a spice simulation like this:

LED 680
.--|<-----|___|-----.
| |
| |9V
| ---
| -
| |
|-------------------'
(created by AACircuit v1.28.5 beta 02/06/05 www.tech-chat.de)

if I place the probe before the 680 ohm resistor, I get 9v, if I place
it between the resistor and the LED I get 1.79V and 10.60mA

I'm trying to understand how I got that number, I know that;
V
I = -
R

if I use that formula with my values:
9
- = 0.013
680

- that makes no sense.
I'm missing something VERY basic and simple, but I can't figure it out.

Yes. You're missing the fact that the voltage across the resistor is

9 - Vf or 9 - Vd, the drop across the diode, V_d, or its forward
voltage, V_f. Plug that in. Hint: V_f is 1.79 V since you're
measuring it relative to 0 V AKA "common" sometimes AKA ground AKA
GND.

I might as well mention that in this group you'll be seeing
notations like Vf and V_f which just means that "f" is a subscript.
We try to do what it takes to get the point across. Look at some
data sheets and parts catalogs.
--
Best Regards,
Mike

 

[Active8]

On Thu, 31 Mar 2005 12:44:58 -0330, Terry wrote:

<snip>

Jason; having just taken a 'transistor' course at an advanced age and being
no expert it looks to me;

1) Upper case designations such Id are for DC.
2) Lower case, such as id are for AC which are the much slighter or 'Small
signal variations' through the device.
DC is the steady or unvarying quantity at one particular point of the
operating characteristic of the device.
3) Without referring to my text book;
Your Eqn. 1 looks to me like it is the one which determines a DC operating
point because it takes into account the threshold (Vgth)! i.e. (Vgs - Vgth)
......

But willing to be corrected!

Close. Lower case variables generally mean "instantaneous" values
i.e., wrt time. Upper case can be DC values (upper case subscript)
or rms and vector values (lower case subs). I the case of Id, the
convention is broken and if you look at a spec sheet, it's I_D. I
think people write Id so that the "d" is understood to be a
subscipt. You just have to take it all in context.

The OP was multi-posted to SED where I wrote a little table of
subsript conventions, so you might look there under the same subject
line.
--
Best Regards,
Mike

 

[John Popelish]

mowhoong wrote:

Thanks John for your explaination. I have another question. A ceramic
disc
capacitor is cheaper than any of the polyester film capacitor, If
both having the same value why can't i use the ceramic disc instead of
polyester
film capacitor if the cicuit is user in a 20w fluorescent light dc to
dc
driver by car battery, is this some thing to do with working frequency
of the capacitor ?

It may be possible to use the cheaper capacitor. No capacitor is
perfect, and you have to decide if the imperfections of a particular
type will be a problem in a given application. Ceramic capacitors
made to be small and cheap have very strange dielectrics that change
capacitance with temperature and also with applied voltage. They also
act as transducers that produce voltage when force is applied to them
and change dimensions when voltage is applied to them. They also tend
to get warmer than film capacitors when charged and discharged rapidly.

Here is a web site that explores many of the details of the various
kinds of capacitors.
http://my.execpc.com/~endlr/index.html
There is a lot to know.

 

[Active8]

On Thu, 31 Mar 2005 09:56:29 -0800, Larry Brasfield wrote:

"Active8" <reply2group@ndbbm.net> wrote in message
news:d2gqd8.2ss.1@active8.fqdn.th-h.de...

[Slack/er stuff zapped.]
What's the Linux equivalent of a disk cluster and what sizes are we
talking about? iNodes come to mind, but I think that's like a FAT
entry.

An inode is more like a FAT filesystem directory entry since
both provide a link or links to the actual file data allocation list.
The Linux equivalent of a disk cluster (in ext2fs, the default lately)
is approximately the 512 byte disk sector, since that is the lowest
level of allocation granularity.

I was just thinking of all the wasted disk space I have from
all the shortcuts - symbolic links, to you. In NTFS a 40 byte or so
URL or 500+ byte shortcut takes up 4 KB - 16 KB on a large FAT32
partition.

You are simply mistaken about how NTFS stores the content
of short files. They go right into the MFT, taking no more
space than the mere existence of another file would. Consider
this screen scrape just now taken from my workstation with
NTFS on device "C:":

=========== screen scrape begins ==============
[C:\Play]
dir *.url

Volume in drive C is unlabeled Serial number is CCCE:6A5D
4NT: (Sys) The system cannot find the file specified.
"C:\Play\*.url"
0 bytes in 0 files and 0 dirs
168,907,882,496 bytes free

[C:\Play]
echo "1234567890123456789012345678901234567890" > x.url

[C:\Play]
dir *.url

Volume in drive C is unlabeled Serial number is CCCE:6A5D
Directory of C:\Play\*.url

3/31/2005 9:37 44 x.url
44 bytes in 1 file and 0 dirs 4,096 bytes allocated
168,907,882,496 bytes free

[C:\Play]
type x.url
"1234567890123456789012345678901234567890"

[C:\Play]

=========== screen scrape ends ==============

Note the similarity of the 12 digit numbers. No space was
taken beyond using an already-allocated MFT entry.

What's MFT?

I hate to bust your bubble, but you're wrong. My NTFS partition
shows (per properties sheet) the actual size of the data and the
"size on disk". For NTFS, it's 4 K - the cluster size. For FAT32,
it's 16 K on my big partition - 8 k on smaller parts.

Notice your list shows 4,096 bytes allocated? You can't go smaller
than a cluster. That's what defrag does. It groups unused clusters
blocks) at the ends of fragged files and makes the data contiguous.
That frees up clusters in cases of severe fragmentation.
--
Best Regards,
Mike

 

[Larry Brasfield]

"Active8" <reply2group@ndbbm.net> wrote in message
news:d2gvtq.3gk.1@active8.fqdn.th-h.de...

On Thu, 31 Mar 2005 09:56:29 -0800, Larry Brasfield wrote:
"Active8" <reply2group@ndbbm.net> wrote in message
news:d2gqd8.2ss.1@active8.fqdn.th-h.de...
....
I was just thinking of all the wasted disk space I have from
all the shortcuts - symbolic links, to you. In NTFS a 40 byte or so
URL or 500+ byte shortcut takes up 4 KB - 16 KB on a large FAT32
partition.

You are simply mistaken about how NTFS stores the content
of short files. They go right into the MFT, taking no more
space than the mere existence of another file would. Consider
this screen scrape just now taken from my workstation with
NTFS on device "C:":

=========== screen scrape begins ==============
[C:\Play]
dir *.url

Volume in drive C is unlabeled Serial number is CCCE:6A5D
4NT: (Sys) The system cannot find the file specified.
"C:\Play\*.url"
0 bytes in 0 files and 0 dirs
168,907,882,496 bytes free

[C:\Play]
echo "1234567890123456789012345678901234567890" > x.url

[C:\Play]
dir *.url

Volume in drive C is unlabeled Serial number is CCCE:6A5D
Directory of C:\Play\*.url

3/31/2005 9:37 44 x.url
44 bytes in 1 file and 0 dirs 4,096 bytes allocated
168,907,882,496 bytes free

[C:\Play]
type x.url
"1234567890123456789012345678901234567890"

[C:\Play]

=========== screen scrape ends ==============

Note the similarity of the 12 digit numbers. No space was
taken beyond using an already-allocated MFT entry.

What's MFT?

Sorry, I did not mean to be cryptic. That acronym
refers to the "Master File Table" maintained in NTFS.
http://www.ntfs.com/ntfs_basics.htm

I hate to bust your bubble, but you're wrong.

Even if I was wrong, my "bubble" would either remain
intact or has been bust for a long time. So please do
not worry yourself about its welfare.

My NTFS partition
shows (per properties sheet) the actual size of the data and the
"size on disk". For NTFS, it's 4 K - the cluster size. For FAT32,
it's 16 K on my big partition - 8 k on smaller parts.

Nothing you've said proves me wrong. Do you believe
the reporting mechanism used by explorer.exe over what
the API's for getting available disk space have to say? I
urge you to study the 3rd sentence past the diagram at:
http://www.ntfs.com/ntfs-mft.htm
For those not eager to follow the link, it states:
Small files and directories (typically 1500 bytes or smaller),
such as the file illustrated in next figure, can entirely be
contained within the master file table record.
That is why you can see the result my screen scrape showed.

Notice your list shows 4,096 bytes allocated? You can't go smaller
than a cluster.

That agrees with my definition of the cluster as the smallest
unit of diskspace allocation. It does not contradict what I
stated or what you can see via the above link.

That's what defrag does. It groups unused clusters
blocks) at the ends of fragged files and makes the data contiguous.
That frees up clusters in cases of severe fragmentation.

That is not what defrag does. It makes the data more
contiguous, (not necessarily completely contiguous) and
it merely reassigns the file content to a new set of clusters
having the same size as the previous set.

Best Regards,
Likewise.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[Mike]

On Thu, 31 Mar 2005 01:30:01 +0000, Rich The Newsgropup Wacko wrote:

Me, too.

My turn again. Checking out Pan.

 

[Active8]

On Thu, 31 Mar 2005 11:33:49 -0800, Larry Brasfield wrote:

"Active8" <reply2group@ndbbm.net> wrote in message
news:d2gvtq.3gk.1@active8.fqdn.th-h.de...
On Thu, 31 Mar 2005 09:56:29 -0800, Larry Brasfield wrote:
"Active8" <reply2group@ndbbm.net> wrote in message
news:d2gqd8.2ss.1@active8.fqdn.th-h.de...
...
I was just thinking of all the wasted disk space I have from
all the shortcuts - symbolic links, to you. In NTFS a 40 byte or so
URL or 500+ byte shortcut takes up 4 KB - 16 KB on a large FAT32
partition.

You are simply mistaken about how NTFS stores the content
of short files. They go right into the MFT, taking no more
space than the mere existence of another file would. Consider
this screen scrape just now taken from my workstation with
NTFS on device "C:":

=========== screen scrape begins ==============
[C:\Play]
dir *.url

Volume in drive C is unlabeled Serial number is CCCE:6A5D
4NT: (Sys) The system cannot find the file specified.
"C:\Play\*.url"
0 bytes in 0 files and 0 dirs
168,907,882,496 bytes free

[C:\Play]
echo "1234567890123456789012345678901234567890" > x.url

[C:\Play]
dir *.url

Volume in drive C is unlabeled Serial number is CCCE:6A5D
Directory of C:\Play\*.url

3/31/2005 9:37 44 x.url
44 bytes in 1 file and 0 dirs 4,096 bytes allocated
168,907,882,496 bytes free

[C:\Play]
type x.url
"1234567890123456789012345678901234567890"

[C:\Play]

=========== screen scrape ends ==============

Note the similarity of the 12 digit numbers. No space was
taken beyond using an already-allocated MFT entry.

What's MFT?

Sorry, I did not mean to be cryptic.

You weren't. I forgot. I studied this a bit. We often have to
clarify thing

That acronym
refers to the "Master File Table" maintained in NTFS.
http://www.ntfs.com/ntfs_basics.htm

I hate to bust your bubble, but you're wrong.

Even if I was wrong, my "bubble" would either remain
intact or has been bust for a long time. So please do
not worry yourself about its welfare.

My NTFS partition
shows (per properties sheet) the actual size of the data and the
"size on disk". For NTFS, it's 4 K - the cluster size. For FAT32,
it's 16 K on my big partition - 8 k on smaller parts.

Nothing you've said proves me wrong.

You own list proves you wrong regarless of what I say.

Do you believe
the reporting mechanism used by explorer.exe over what
the API's for getting available disk space have to say?

I've used those APIs and so does the explorer properties applet.

I
urge you to study the 3rd sentence past the diagram at:

I urge you to learn to read Notice that sentence says *can*, not
*are*.

As you would put it, you are assuming things not in evidence.

http://www.ntfs.com/ntfs-mft.htm
For those not eager to follow the link, it states:
Small files and directories (typically 1500 bytes or smaller),
such as the file illustrated in next figure, can entirely be
contained within the master file table record.

I vaguely remember reading something like that, perhaps in the MSDN.
But I won't assume that the OS is doing the right thing. After all,
both your list and my file properties are correctly showing the
"bytes allocated" and "space on disk", respectively.

That is why you can see the result my screen scrape showed.

Which proves you wrong in no uncertain terms.

Notice your list shows 4,096 bytes allocated? You can't go smaller
than a cluster.

That agrees with my definition of the cluster as the smallest
unit of diskspace allocation. It does not contradict what I
stated or what you can see via the above link.

It's not just *your* definition. I for one, just paraphrased it.

That's what defrag does. It groups unused clusters
blocks) at the ends of fragged files and makes the data contiguous.
That frees up clusters in cases of severe fragmentation.

That is not what defrag does. It makes the data more
contiguous, (not necessarily completely contiguous) and
it merely reassigns the file content to a new set of clusters
having the same size as the previous set.

Think about that. If you have 100 frags of a file and each frag does
not completely fill the last cluster, you'll free up clusters by
defragging. In order to make the file contiguous, it often needs to
move the next file somewhere else so it can put free clusters at the
end of said file.
--
Best Regards,
Mike

 

[Larry Brasfield]

"Active8" <reply2group@ndbbm.net> wrote in message
news:d2h34o.3a4.1@active8.fqdn.th-h.de...

On Thu, 31 Mar 2005 11:33:49 -0800, Larry Brasfield wrote:
"Active8" <reply2group@ndbbm.net> wrote in message
news:d2gvtq.3gk.1@active8.fqdn.th-h.de...
On Thu, 31 Mar 2005 09:56:29 -0800, Larry Brasfield wrote:
"Active8" <reply2group@ndbbm.net> wrote in message
news:d2gqd8.2ss.1@active8.fqdn.th-h.de...
...
I was just thinking of all the wasted disk space I have from
all the shortcuts - symbolic links, to you. In NTFS a 40 byte or so
URL or 500+ byte shortcut takes up 4 KB - 16 KB on a large FAT32
partition.

You are simply mistaken about how NTFS stores the content
of short files. They go right into the MFT, taking no more
space than the mere existence of another file would. Consider
this screen scrape just now taken from my workstation with
NTFS on device "C:":

=========== screen scrape begins ==============
[C:\Play]
dir *.url

Volume in drive C is unlabeled Serial number is CCCE:6A5D
4NT: (Sys) The system cannot find the file specified.
"C:\Play\*.url"
0 bytes in 0 files and 0 dirs
168,907,882,496 bytes free

[C:\Play]
echo "1234567890123456789012345678901234567890" > x.url

[C:\Play]
dir *.url

Volume in drive C is unlabeled Serial number is CCCE:6A5D
Directory of C:\Play\*.url

3/31/2005 9:37 44 x.url
44 bytes in 1 file and 0 dirs 4,096 bytes allocated
168,907,882,496 bytes free

[C:\Play]
type x.url
"1234567890123456789012345678901234567890"

[C:\Play]

=========== screen scrape ends ==============

Note the similarity of the 12 digit numbers. No space was
taken beyond using an already-allocated MFT entry.

['MFT' meaning, bubble frivolity cut.]

My NTFS partition
shows (per properties sheet) the actual size of the data and the
"size on disk". For NTFS, it's 4 K - the cluster size. For FAT32,
it's 16 K on my big partition - 8 k on smaller parts.

Nothing you've said proves me wrong.

You own list proves you wrong regarless of what I say.

My first post on this thread was responding to your claim,
(and I quote verbatum): " In NTFS a 40 byte or so URL
or 500+ byte shortcut takes up 4 KB".

Do you believe
the reporting mechanism used by explorer.exe over what
the API's for getting available disk space have to say?

I've used those APIs and so does the explorer properties applet.

I
urge you to study the 3rd sentence past the diagram at:

I urge you to learn to read Notice that sentence says *can*, not
*are*.

Your statement, the one I posted to refute, stated "In NTFS a 40 byte
or so URL or 500+ byte shortcut takes up 4 KB". To refute that
unequivocal statement only requires one counterexample.

Now, maybe to cut this short, (and forgive me for providing
your own argument, if it does not work for you), that MFT
entry does occupy some space which, absent the existence
of the file itself, would be available for another file. And,
depending on the parameters used during NTFS formatting,
that space could be 4 KB, (for all I've claimed). However,
before you get too excited about my bubble or some such,
please remember my limited claim regarding short files:
"They go right into the MFT, taking no more space than the
mere existence of another file would."

As you would put it, you are assuming things not in evidence.

I would love to say "touche" on that point. But that pleasure
would be prematurely taken just now.

http://www.ntfs.com/ntfs-mft.htm
For those not eager to follow the link, it states:
Small files and directories (typically 1500 bytes or smaller),
such as the file illustrated in next figure, can entirely be
contained within the master file table record.

I vaguely remember reading something like that, perhaps in the MSDN.
But I won't assume that the OS is doing the right thing.

But you surely would grant that it *may* be doing the right
thing, in the absence of evidence to the contrary, right? And
you surely can count the unchanged disk space consumption
apparent in my screen scrape as some evidence that my little
40+ byte file content went into the MFT, right? (I assure you,
I did not delete any files to artifically create that result.)

After all,
both your list and my file properties are correctly showing the
"bytes allocated" and "space on disk", respectively.

That is why you can see the result my screen scrape showed.

Which proves you wrong in no uncertain terms.

My list (by which I presume you mean the screen scrape) shows
no additional bytes allocated. As far as I can see, it supports
my limited claim and does not contradict it. If you see otherwise,
please be more specific as to what claim of mine it disproves.

Notice your list shows 4,096 bytes allocated? You can't go smaller
than a cluster.

That agrees with my definition of the cluster as the smallest
unit of diskspace allocation. It does not contradict what I
stated or what you can see via the above link.

It's not just *your* definition. I for one, just paraphrased it.

Granted. Same here.

That's what defrag does. It groups unused clusters
blocks) at the ends of fragged files and makes the data contiguous.
That frees up clusters in cases of severe fragmentation.

That is not what defrag does. It makes the data more
contiguous, (not necessarily completely contiguous) and
it merely reassigns the file content to a new set of clusters
having the same size as the previous set.

Think about that. If you have 100 frags of a file and each frag does
not completely fill the last cluster, you'll free up clusters by
defragging.

Your antecedent does not occur. File content completely
fills all but the last cluster. There is no mechanism for
tracking partial cluster usage other than the recorded
file size, and that predicts the integer number of clusters
used and the fraction of the last cluster used. If you do
not believe this, please provide some evidence regarding
partial cluster usage except at the end of a file.

In order to make the file contiguous, it often needs to
move the next file somewhere else so it can put free clusters at the
end of said file.

I've studied the on-disk format for FAT file systems,
(including CPM), and never seen anything that would
facilitate the operation you just described. And as you
can see from the reference I provided, NTFS does
not work that way either.

Best Regards,
Returned,

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[John Popelish]

eeh wrote:

What is the difference between T-filter LP filter and RC LP filter?

I know T-filter is

---R---R---
|
C
|

and RC LP filter is

---R-------
|
C
|

The differrence is just a resistor more.

What is their performance difference?

That depends very much on the impedance of whatever receives the
output signal. If that impedance is very high compared to either
resistor, then the second resistor has almost no effect.

If the receiving impedance is very much less than either R, then the
second resistor effectively isolates the receiving impedance from the
filter.

 

[Robert Monsen]

holmsy wrote:

what i need is sort of a muting circuit

i need a cicuit that has two audio inputs(we'll call them 1 and 2) and
the circuit alows input2 to play continuously untill there is a signal
from input1 then input2 will be muted while there is a signal coming
from input1 and then once there is no more signal from input1 it will
wait for around a minute before it alows sound from input2 again.

sort of so that you can listen to input2 but as soon as something
comes from input1 it has priority so that you cant miss it.

has anyone seen anything like this? does anyone know where i can get a
circuit diagram for something like that? does anyone have a circuit
diagram like that?

There are cd players and such for aircraft that do this. When the
controller talks, it mutes the stereo output. I don't know how they do
it, but it might be a place to start looking.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Active8]

On Thu, 31 Mar 2005 12:33:22 -0800, Larry Brasfield wrote:

"Active8" <reply2group@ndbbm.net> wrote in message
news:d2h34o.3a4.1@active8.fqdn.th-h.de...
On Thu, 31 Mar 2005 11:33:49 -0800, Larry Brasfield wrote:
"Active8" <reply2group@ndbbm.net> wrote in message
snip

=========== screen scrape begins ==============
[C:\Play]
dir *.url

Volume in drive C is unlabeled Serial number is CCCE:6A5D
4NT: (Sys) The system cannot find the file specified.
"C:\Play\*.url"
0 bytes in 0 files and 0 dirs
168,907,882,496 bytes free
^^^^^^^^^ important thing I missed

[C:\Play]
echo "1234567890123456789012345678901234567890" > x.url

[C:\Play]
dir *.url

Volume in drive C is unlabeled Serial number is CCCE:6A5D
Directory of C:\Play\*.url

3/31/2005 9:37 44 x.url
44 bytes in 1 file and 0 dirs 4,096 bytes allocated
^^^^^^^^^^ WTF?
168,907,882,496 bytes free
^^^^^^^^^ important thing I missed

[C:\Play]
type x.url
"1234567890123456789012345678901234567890"

[C:\Play]

=========== screen scrape ends ==============

Note the similarity of the 12 digit numbers. No space was
taken beyond using an already-allocated MFT entry.

You might have said, "check the 'bytes free' line" and avoided
confusion. Yet you snipped info and instead of just saying "<snip>",
you had to call it "frivolity".
<snip>

So...

1. Why does your shell print 4,096 bytes allocated? Mine doesn't.
But the properties applet does, except it's worded as "size on
disk".

*********
Volume in drive C has no label.
Volume Serial Number is 7862-9D07

Directory of C:\0

04/01/2005 02:08 AM 29 x.url
1 File(s) 29 bytes
0 Dir(s) 1,196,507,136 bytes free
**********

2. What version of winders are you using? I tested this out here and
the NTFS is working as advertised, but FAT32 is doing that which I
expected - wasting space. Your shell is outputting the dir command
differently. Just curious.

As far as I can see, it supports
my limited claim and does not contradict it. If you see otherwise,
please be more specific as to what claim of mine it disproves.

The line I highlighted diverted my focus from the one that mattered.
<snip>

That's what defrag does. It groups unused clusters
blocks) at the ends of fragged files and makes the data contiguous.
That frees up clusters in cases of severe fragmentation.

That is not what defrag does. It makes the data more
contiguous, (not necessarily completely contiguous) and
it merely reassigns the file content to a new set of clusters
having the same size as the previous set.

Think about that. If you have 100 frags of a file and each frag does
not completely fill the last cluster, you'll free up clusters by
defragging.

Your antecedent does not occur. File content completely
fills all but the last cluster. There is no mechanism for
tracking partial cluster usage other than the recorded
file size, and that predicts the integer number of clusters
used and the fraction of the last cluster used. If you do
not believe this, please provide some evidence regarding
partial cluster usage except at the end of a file.

X = one full cluster of data
x = exactly 1/2 cluster of data

frag1: XXXX x frag2: XXXX x
^ ^ takes a whole cluster

so that's 2 frags occupying 10 clusters

defrag: XXXX XXXX X

count 9 clusters. Thus, defragging freed one cluster.

In order to make the file contiguous, it often needs to
move the next file somewhere else so it can put free clusters at the
end of said file.

I've studied the on-disk format for FAT file systems,
(including CPM), and never seen anything that would
facilitate the operation you just described. And as you
can see from the reference I provided, NTFS does
not work that way either.

Like I said, I vaguely remember the "file in the MFT" feature of
NTFS. It just looked like it wasn't living up to the claim.

Best Regards,
Returned,

Justs put "BRs", "cheers", or whatever in your signature block. And
prepend the damn thing with "--" so our *real* news readers can omit
it on reply.
--
Best Regards,
Mike

 

[Lord Garth]

"smokie" <stillbreezy@gmail.com> wrote in message
news:1112337309.835937.306160@z14g2000cwz.googlegroups.com...

what happens if you short the output on an inverting amplifier to its
inverting input?

Here's a place that will explain it to you:

http://www.williamson-labs.com/480_opam.htm

Your text indicates the feedback is zero ohms, drop that into the equation
for an inverting amp and get back to us.

 

[Andrew Holme]

Thomas wrote:

I am trying to activate a relay when the vehicle is in anything other
than Park. The transmission module sends out 5V @ 120hz with varying
pulse widths. In Park, I read 0.71V with the meter and looks to be
apprx 1/7th of the pulse on the scope (square wave). In Reverse, the
pulse is measured at 1.6V of 1/3 of the pulse with higher voltages and
pulse widths in N,D,2. I've tried using this to enable a small dc
relay, but only get chatter (even in Park). I've been told I could do
the following...

RC Integrator - Unity-Gain OpAmp Buffer - Comparator

How would this work? Any help is greatly appreciated.

The RC integrator will smooth-out the pulses, giving you a DC voltage
proportional to the pulse width.

Your meter is doing the same thing i.e. reading the average level.

The comparator gives you a digital output indicating whether the voltage is
above or below some threshold. You'll need positive feedback (hysteresis)
around the comparator to cope with residual ripple.

There are two tweak-factors to play with:
1. RC time constant
2. Amount of hysteresis

Long time constant = more smoothing = slower response to change
Short time constant = fast response, but more residual ripple on DC voltage
= more hysteresis required

Given the application, a time constant of up to 1 second should be OK, and
would provide effective smoothing at 120Hz.

You won't need a unity gain op-amp buffer if the RC filter output is the
only thing connected to the inverting input of the comparator; and the
threshold preset, and postive feedback resistor, are connected to the
non-inverting input.

 

[Active8]

On Fri, 01 Apr 2005 05:19:55 -0500, Mike wrote:

On Thu, 31 Mar 2005 14:32:41 -0500, Mike wrote:

On Thu, 31 Mar 2005 01:30:01 +0000, Rich The Newsgropup Wacko wrote:
Me, too.

My turn again. Checking out Pan.

grrrrrr...
this should do it

 

[Mike]

On Thu, 31 Mar 2005 14:32:41 -0500, Mike wrote:

On Thu, 31 Mar 2005 01:30:01 +0000, Rich The Newsgropup Wacko wrote:
Me, too.

My turn again. Checking out Pan.

grrrrrr...

 

[Active8]

On Fri, 1 Apr 2005 03:12:12 -0800, Larry Brasfield wrote:

"Active8" <reply2group@ndbbm.net> wrote in message
snip

Volume in drive C is unlabeled Serial number is CCCE:6A5D
Directory of C:\Play\*.url

3/31/2005 9:37 44 x.url
44 bytes in 1 file and 0 dirs 4,096 bytes allocated
^^^^^^^^^^ WTF?

That means the directory listing specified did not include
any subdirectories. (Nothing that strange, really.)

That's what "0 dirs" means.

"^^^^^^^^^^^ WTF?" means that I'd like to know what's up with the
"4,096 bytes allocated" part. That's why I highlighted those
particular characters.
--
Best Regards,
Mike

 

[John Popelish]

smokie wrote:

what happens if you short the output on an inverting amplifier to its
inverting input?

It is programmed to have zero voltage gain.

 

[Bob Masta]

On 31 Mar 2005 17:37:38 -0800, holmsy2000@hotmail.com (holmsy) wrote:

what i need is sort of a muting circuit

i need a cicuit that has two audio inputs(we'll call them 1 and 2) and
the circuit alows input2 to play continuously untill there is a signal
from input1 then input2 will be muted while there is a signal coming
from input1 and then once there is no more signal from input1 it will
wait for around a minute before it alows sound from input2 again.

sort of so that you can listen to input2 but as soon as something
comes from input1 it has priority so that you cant miss it.

has anyone seen anything like this? does anyone know where i can get a
circuit diagram for something like that? does anyone have a circuit
diagram like that?

I think what you want is what is sold commerically as a
"ducking" amp, or typically a ducking circuit on a mixer, or
compressor. (For annoying DJs to talk over your favorite songs, etc.)
Basically, you extract the envelope of Input1 (full-wave
active rectifier with low-pass filter) and feed that to a threshold
comparator that runs the mute, including adjustable ramps (fast
fade-down and slow fade-up.)

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com

 

[Jamie]

Thomas wrote:

I am trying to activate a relay when the vehicle is in anything other
than Park. The transmission module sends out 5V @ 120hz with varying
pulse widths. In Park, I read 0.71V with the meter and looks to be
apprx 1/7th of the pulse on the scope (square wave). In Reverse, the
pulse is measured at 1.6V of 1/3 of the pulse with higher voltages and
pulse widths in N,D,2. I've tried using this to enable a small dc
relay, but only get chatter (even in Park). I've been told I could do
the following...

RC Integrator - Unity-Gain OpAmp Buffer - Comparator

How would this work? Any help is greatly appreciated.

you need a Window Comparator. the output of the comparator

can operate a Time Off Delay circuit. each time it triggers
it will recharge the Time off or initially start it.

the whole thing could be built around a simple thing like a
LM324 which has 4 op-amps in one package.
2 of them used as the window comparator.
#3 a slight Time on delay buffer, #4, A time off Delay comparator.

the time off delay is tailured to hold the output steady between
your 120Hz Rates.

look on the net for "Window Comparator"
and also look for using a OP-Amp as a time delay and time off
delay.
http://home.cogeco.ca/~rpaisley4/Comparators.html