Circuit minimization

On Mon, 17 May 2004 11:03:14 -0700, Jim Thompson
<thegreatone@example.com> wrote:

On Mon, 17 May 2004 10:51:31 -0700, "Richard Henry" <rphenry@home.com
wrote:


"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote in
message news:56sha057knt2cn7a66uratd2fi3ac4o96c@4ax.com...
On Mon, 17 May 2004 09:51:33 -0700, Jim Thompson
thegreatone@example.com> wrote:



Well, duh! ANY combinational logic inherently has glitches UNLESS
either (1) the inputs are sequenced (say with multiple clocks) or (2)
the outputs are strobed during a period that inputs are not changing.

or (3) you hang a big capacitor from output to ground.

I went to a job interview once where the chief engineer (a big, bearded
biker that everyone in the comapny called "Mad Dog") wanted to be sure that
I didn't design digital circuits with capacitive delay elements.
[snip]

I knew a fellow like that, named Ed Greenwood (now deceased), at
GenRad, big (as in >> 300#), bearded, quite tall.

He was noted for *dragging* a car out of his reserved parking space by
simply throwing a chain around the axle and pulling it out into the
aisle-way. Turned out to be a customer's rental car ;-)

He'd kill you if you used a one-shot anywhere!

...Jim Thompson
One of my VME customers (who makes the engines for the planes we all
fly on) had a nasty intermittent problem with one of our modules
recently. They'd work fine alone, but would reset/reboot if certain
other cards were in the rack. Turns out somebody was making glitches
on the \SYSRESET line. I'd tell you how we fixed it, but you might
kill me.

Actually, synchronous logic is just a mental crutch for people who
can't figure out real spaghetti logic. Async logic is threatening to
make a comeback, now that fully-clocked CMOS is starting to melt
chips. Rumor has it that part of the Pentium 4 is done in async logic.

There was a big project at TI once, ASC, where all TTL presets and
clears had to be tied high.

John
 
On Mon, 17 May 2004 10:54:07 -0700, "Richard Henry" <rphenry@home.com>
wrote:

"Jim Thompson" <thegreatone@example.com> wrote in message
news:r3sha0hjknlkppd42sd40monnia7b1lj61@4ax.com...

I try to daily walk down the hill to the community mailboxes and then
walk back up (600' and 30' rise), but I often just make it a stop as
I'm driving somewhere :-(

After I "retired" last October, i started running 3-5 miles several mornings
a week. Recently, my wife has had me working on a variety of
home-improvement projects which more than replace the aerobic intensity of
the running.
Good. Running a lot will eventually pound your joints apart.

John
 
In article <GY6qc.57435$iy5.289@okepread05>,
"Richard Henry" <rphenry@home.com> writes:
Coincidentally, about the same time, a friend had to redesign a digital
filter design that had been "tuned" with pots and caps all over the board.
While the engineering prototype worked flawlessly, the design did not
survive the transfer to production.

I thought that I was the only person to experience such silly design
techniques (luckily, I fixed the design before production.) The
circuit was developed in the 1977 timeframe, and used the old
4116 type DRAMs. Those devices required a fairly well controlled
RAS/CAS delay, and the 6502 processor (1MHz, 2MHz clocked at 1MHz
later on) didn't have well specified clock-in vs effective I/O
clock delays... The external clock generator versions of the 6502s
did have a specified I/O clock delay, but we weren't able to use
that for various reasons (that I don't remember.) Unfortunately,
the original hack design used
a resistor and gate threshold and capacitance to effect the RAS
to CAS delay!!! The original (happily aborted) production design
even had a POT to effect a RAS/CAS delay tweak!!! Well, when I finally
won the argument that the quality of the product would suffer (in
fact, the environment was industrial, so not well
controlled), I 'solved' the problem with a brute force
delay line. If I wasn't so pressured by time, I might have
re-considered a high speed clocked approach, but the delay line
did minimize parts count and guaranteed a 'works first time'
result. (The clocked version also had some precision issues,
due to the timing margins, but I probably could have gotten
it to work reliably given a week or so of design time.)

Anyway, the need for redesign did cause a dust-up at work, but
we really needed to produce a reliable design. The RC and
gate threshold delay was so unstable, that even our lab versions
of the DRAM board needed to be 'readjusted' periodically. I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!

John
 
On Mon, 17 May 2004 21:05:03 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!
---
If you were anything then like the blowhard bullshit artist you are
now, he probably wanted as little to do with you as possible.


--
John Fields
 
In article <uqaia0tf82ueim3q0kli852b1jtgpipnmu@4ax.com>,
crazed John Fields <jfields@austininstruments.com> blathered off topic:
On Mon, 17 May 2004 21:05:03 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!

---
If you were anything then like the blowhard bullshit artist you are
now, he probably wanted as little to do with you as possible.

John, what is your G*d D*mn*d problem? Can't you forget about
your hate? Are you so consumed by hatred (especially about
the proof about John Kerry's lies or war crimes) that you cannot
control yourself? That was obviously your hot button, and it
appears that you have invested too much into the
creepy John Kerry-Heinz...

John
 
"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote in
message news:0r8ia0ds3jkskn0cpj5h6kjcl0e97sll1h@4ax.com...
On Mon, 17 May 2004 10:54:07 -0700, "Richard Henry" <rphenry@home.com
wrote:

After I "retired" last October, i started running 3-5 miles several
mornings
a week. Recently, my wife has had me working on a variety of
home-improvement projects which more than replace the aerobic intensity
of
the running.

Good. Running a lot will eventually pound your joints apart.
Painting eaves and insulating ceilings is doing a job on my shoulders.
 
"John S. Dyson" <toor@iquest.net> wrote in message
news:c8b9dv$19op$1@news.iquest.net...

Anyway, the need for redesign did cause a dust-up at work, but
we really needed to produce a reliable design. The RC and
gate threshold delay was so unstable, that even our lab versions
of the DRAM board needed to be 'readjusted' periodically. I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!
He was probably wondering, "What's this guy wanting to set me
up for?"

Cheers!
Rich
 
On Mon, 17 May 2004 22:13:11 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

In article <uqaia0tf82ueim3q0kli852b1jtgpipnmu@4ax.com>,
crazed John Fields <jfields@austininstruments.com> blathered off topic:
On Mon, 17 May 2004 21:05:03 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!

---
If you were anything then like the blowhard bullshit artist you are
now, he probably wanted as little to do with you as possible.

John, what is your G*d D*mn*d problem? Can't you forget about
your hate? Are you so consumed by hatred (especially about
the proof about John Kerry's lies or war crimes) that you cannot
control yourself? That was obviously your hot button, and it
appears that you have invested too much into the
creepy John Kerry-Heinz...
---
Hey, asshole pussy,

I don't have to abridge what I want to say by hiding behind a bunch of
pretentious abbreviations like cocksuckers like you obviously have to.

I can write "God Damned problem" without having to pussy out and suck
the censors' dicks like you think you have to in order to come up with
and be allowed to post garbage like "G*d D*mn*d problem", so take your

dopey analyses (note the "anal" part of it) and stuff them up your ..s


--
John Fields
 
In article <6qtia09qoq83oh33g3jmbtguosvsl35k41@4ax.com>,
John Fields <jfields@austininstruments.com> writes:
On Mon, 17 May 2004 22:13:11 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

In article <uqaia0tf82ueim3q0kli852b1jtgpipnmu@4ax.com>,
crazed John Fields <jfields@austininstruments.com> blathered off topic:
On Mon, 17 May 2004 21:05:03 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!

---
If you were anything then like the blowhard bullshit artist you are
now, he probably wanted as little to do with you as possible.

John, what is your G*d D*mn*d problem? Can't you forget about
your hate? Are you so consumed by hatred (especially about
the proof about John Kerry's lies or war crimes) that you cannot
control yourself? That was obviously your hot button, and it
appears that you have invested too much into the
creepy John Kerry-Heinz...

---
Hey, asshole pussy,

Thank you for showing more of your intellect... You are so, so
very intellectually limited like other lefties. Your fixation
or confusion with excretory and sexual organs might be helpful
in your diagnosis of your problems...

Are you really so very emotionally screwed up, or are you just being
silly in a wierd way? How do your
customers feel with such an unstable person being involved in
important projects, and how could they possibly trust you? Have
you been hiding your instability from them? Geesh, I have run
into only a few wierdos on the net as unstable as you appear
to be... I mean, the LBJ Library types are probably accepting
of your instability (like many Democrats are weird today), but
more legitimate companies need to be more careful, wouldn't you
think?

John
 
John S. Dyson wrote:
In article <6qtia09qoq83oh33g3jmbtguosvsl35k41@4ax.com>,
John Fields <jfields@austininstruments.com> writes:
On Mon, 17 May 2004 22:13:11 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

In article <uqaia0tf82ueim3q0kli852b1jtgpipnmu@4ax.com>,
crazed John Fields <jfields@austininstruments.com> blathered off topic:
On Mon, 17 May 2004 21:05:03 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!

---
If you were anything then like the blowhard bullshit artist you are
now, he probably wanted as little to do with you as possible.

John, what is your G*d D*mn*d problem? Can't you forget about
your hate? Are you so consumed by hatred (especially about
the proof about John Kerry's lies or war crimes) that you cannot
control yourself? That was obviously your hot button, and it
appears that you have invested too much into the
creepy John Kerry-Heinz...

---
Hey, asshole pussy,

Thank you for showing more of your intellect... You are so, so
very intellectually limited like other lefties. Your fixation
or confusion with excretory and sexual organs might be helpful
in your diagnosis of your problems...

Are you really so very emotionally screwed up, or are you just being
silly in a wierd way?
-------------------
No, he was telling you you're a obviously a cock-sucking little
cowardly pussy, as you surely are!


How do your
customers feel with such an unstable person being involved in
important projects, and how could they possibly trust you? Have
you been hiding your instability from them?
---------------------
He's obviously both competent, and right! so THEY DON'T CARE!!


Geesh, I have run
into only a few wierdos on the net as unstable as you appear
to be...
----------------------
You're the only delusional little shit among the three of us.


I mean, the LBJ Library types are probably accepting
of your instability (like many Democrats are weird today),
-------------------
NOBODY knows what this means, if anything! You're INSANE!


but more legitimate companies need to be more careful, wouldn't
you think?
John
------------------------
Nope, nor does anyone else.

-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
 
"Rich Grise" <null@example.net> wrote in message
news:QIdqc.136686$G_.15569@nwrddc02.gnilink.net...
"John S. Dyson" <toor@iquest.net> wrote in message
news:c8b9dv$19op$1@news.iquest.net...

Anyway, the need for redesign did cause a dust-up at work, but
we really needed to produce a reliable design. The RC and
gate threshold delay was so unstable, that even our lab versions
of the DRAM board needed to be 'readjusted' periodically. I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!

He was probably wondering, "What's this guy wanting to set me
up for?"

The design was so darned incompetent (looking at hindsight) that I
was actually worried
when we were considering it for production. I mean, can you actually
imagine using the delay (needing perhaps 10-20% accuracy) based
upon a CMOS input threshold and
an RC delay (partially constructed from the input capacitance), and
the design has to work from below -10C to approx 45C!!! Spotting
the problem is a no-brainer, and I had very positively cooperated with
making things work correctly (ego-less development.) The problem
is that he had let his ego become involved in an errant design. The
delay had to be accurate within a few nanoseconds (I forget exactly
how much, but perhaps +-20ns.) Doing the delay with a clocked
scheme might have been feasable, but I would have had to do a more
careful analysis due to the async nature of the clock. The analog
delay line made the design a little less fragile because of the effectively
infinite resolution of the delay (instead of being quantized.) If
production volumes would have been at the 10K-100K level, I probably
would have redesigned the board for more cost effective components,
but at the 100-1K quantity level for the first versions, the delay line
was initially satisfactory.

Note that my 'solution' was also suboptimal WRT the production cost,
and parts availability, but I didn't have time to solve the problem
correctly
and guarantee a production worthy design given my time constraints.
It isn't helpful to let egos get involved in engineering decisions. This
seems to be a too-common flaw with engineers (who sometimes develop
an artistic temperment.) Perhaps that isn't really just a flaw of
engineers,
but might just be human nature?!?!?

John
 
"R. Steve Walz" <rstevew@armory.com> wrote in message
news:40A99122.5F19@armory.com...
John S. Dyson wrote:

In article <6qtia09qoq83oh33g3jmbtguosvsl35k41@4ax.com>,
John Fields <jfields@austininstruments.com> writes:
On Mon, 17 May 2004 22:13:11 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

In article <uqaia0tf82ueim3q0kli852b1jtgpipnmu@4ax.com>,
crazed John Fields <jfields@austininstruments.com> blathered off
topic:
On Mon, 17 May 2004 21:05:03 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!

---
If you were anything then like the blowhard bullshit artist you are
now, he probably wanted as little to do with you as possible.

John, what is your G*d D*mn*d problem? Can't you forget about
your hate? Are you so consumed by hatred (especially about
the proof about John Kerry's lies or war crimes) that you cannot
control yourself? That was obviously your hot button, and it
appears that you have invested too much into the
creepy John Kerry-Heinz...

---
Hey, asshole pussy,

Thank you for showing more of your intellect... You are so, so
very intellectually limited like other lefties. Your fixation
or confusion with excretory and sexual organs might be helpful
in your diagnosis of your problems...

Are you really so very emotionally screwed up, or are you just being
silly in a wierd way?
-------------------
No, he was telling you you're a obviously a cock-sucking little
cowardly pussy, as you surely are!

Again, your off topic sex/excretory fixations are really odd, and
really do show some problems in your early development (not just
sexual, but emotional maturity.) For off topic attacks,
refer to yourself and John Fields subverting this thread. If you aren't
too far gone, there are probably therapies and drugs that can help
you. It would be good if you could adhere to reasonable etiquette
by keeping political discussions on apparently political subjects and
threads.

John
 
"John Dyson" <dyson@iquest.net> schreef in bericht
news:c8c57q$1hvj$1@news.iquest.net...

[snip]

you. It would be good if you could adhere to reasonable etiquette
by keeping political discussions on apparently political subjects and
threads.
The master of 'Etiquette' speaks, and changes the folluw-up to
alt.flame, well, I am not impressed.

--
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)
 
John Dyson wrote:
"R. Steve Walz" <rstevew@armory.com> wrote in message
news:40A99122.5F19@armory.com...
John S. Dyson wrote:

In article <6qtia09qoq83oh33g3jmbtguosvsl35k41@4ax.com>,
John Fields <jfields@austininstruments.com> writes:
On Mon, 17 May 2004 22:13:11 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

In article <uqaia0tf82ueim3q0kli852b1jtgpipnmu@4ax.com>,
crazed John Fields <jfields@austininstruments.com> blathered off
topic:
On Mon, 17 May 2004 21:05:03 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!

---
If you were anything then like the blowhard bullshit artist you are
now, he probably wanted as little to do with you as possible.

John, what is your G*d D*mn*d problem? Can't you forget about
your hate? Are you so consumed by hatred (especially about
the proof about John Kerry's lies or war crimes) that you cannot
control yourself? That was obviously your hot button, and it
appears that you have invested too much into the
creepy John Kerry-Heinz...

---
Hey, asshole pussy,

Thank you for showing more of your intellect... You are so, so
very intellectually limited like other lefties. Your fixation
or confusion with excretory and sexual organs might be helpful
in your diagnosis of your problems...

Are you really so very emotionally screwed up, or are you just being
silly in a wierd way?
-------------------
No, he was telling you you're a obviously a cock-sucking little
cowardly pussy, as you surely are!

Again, your off topic sex/excretory fixations are really
----------------
It's entirely appropriate to use the term shit to describe you,
you shit-fucking lying piece of vicious fundy crap.


odd, and
really do show some problems in your early development (not just
sexual,
------------------
Absolute nonsense.


but emotional maturity.)
----------------
I'm mature enough to know you're nothing but a filthy piece of shit,
and that's all anyone needs to know about you.


For off topic attacks,
refer to yourself and John Fields subverting this thread.
-----------------
Nothing of the kind, you steaming turd.


If you aren't
too far gone, there are probably therapies and drugs that can help
you.
-----------------
You're a lying little posturing filthy asshole, nothing more.


It would be good if you could adhere to reasonable etiquette
by keeping political discussions on apparently political subjects and
threads.

John
--------------------
Eat shit and die, you human-shaped piece of lying pig-shit.

-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
 
John Fields wrote...
John S. Dyson wrote:

John, what is your G*d D*mn*d problem? Can't you forget about
your hate? Are you so consumed by hatred (especially about
the proof about John Kerry's lies or war crimes) that you cannot
control yourself? That was obviously your hot button, and it
appears that you have invested too much into the
creepy John Kerry-Heinz...

---
Hey, asshole pussy,

I don't have to abridge what I want to say by hiding behind a bunch of
pretentious abbreviations like cocksuckers like you obviously have to.

I can write "God Damned problem" without having to pussy out and suck
the censors' dicks like you think you have to in order to come up with
and be allowed to post garbage like "G*d D*mn*d problem", so take your
dopey analyses (note the "anal" part of it) and stuff them up your ..s
Hey, John, now that you've been labeled by the resident <ahem>
centrist <cough> sicko, as a Kerry supporter <snicker>, and a
leftie <snort>, how about making a campaign contribution? <ha
hah hahahakhbs^@$^!> [ok, hahah, breath deeply, haha, calm down,
snork] Here, get some good sense. http://www.johnkerry.com/
With nuts and weirdo's like John S. Dyson arrayed against him,
John Kerry is looking better and better all the time.

Thanks,
- Win

(email: use hill_at_rowland-dot-org for now)
 
On Mon, 17 May 2004 17:20:12 -0700, "Richard Henry" <rphenry@home.com> posted
this:

"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote in
message news:0r8ia0ds3jkskn0cpj5h6kjcl0e97sll1h@4ax.com...
On Mon, 17 May 2004 10:54:07 -0700, "Richard Henry" <rphenry@home.com
wrote:

After I "retired" last October, i started running 3-5 miles several
mornings
a week. Recently, my wife has had me working on a variety of
home-improvement projects which more than replace the aerobic intensity
of
the running.

Good. Running a lot will eventually pound your joints apart.

Painting eaves and insulating ceilings is doing a job on my shoulders.
My grandmother is 87 years old. Two years ago she started running three
miles a day. Now we don't know where the hell she is.

Jim "straight line" Meyer
 
On Tue, 18 May 2004 04:25:48 GMT, "R. Steve Walz" <rstevew@armory.com>
wrote:

John S. Dyson wrote:


I mean, the LBJ Library types are probably accepting
of your instability (like many Democrats are weird today),
-------------------
NOBODY knows what this means, if anything! You're INSANE!
---
He _is_ insane, and what the chickenshit little coward did was to go
to my web site and look around for stuff that he thought he could use
for his pathetic little smear tactics.

The Lyndon Baines Johnson library here in Austin is one of my clients,
and Dyson is so obsessed with his hatred for the left that even the
word 'library' smacks, to him, of something other than the totally
repressive world he'd like to force into being and lord over.

--
John Fields
 
Jim Thompson wrote:

On Mon, 17 May 2004 16:19:29 +0000 (UTC), Soeren
Look@iNO-SPAMt.dk.invalid> wrote:


Hi Michael,



Naw, not really. Here we always interpose a latch between
combinatorial and down-stream stuff. :)

So much for optimisation to minimal circuitry ;-P

What you do is a bit more waistful than securing the outputs in the first
place, but each to his own ways :)


Well, duh! ANY combinational logic inherently has glitches UNLESS
either (1) the inputs are sequenced (say with multiple clocks) or (2)
the outputs are strobed during a period that inputs are not changing.

Looks like you've never designed a disaster and gained what we old
farts call "experience" ;-)

...Jim Thompson
Or you just get lucky! :cool:

About 10 years ago, designed a little interface board to take a bunch of
sensors (IR Laser presence detectors) and combine them. Boss wanted to
be able to only give a valid 'present' output if a car went through
forward, plus we needed to classify what lane the car was in. Since I
didn't have any PLDs, or the tools to program them, but did have an
EPROM programmer, built a bunch of state machines out of an 16x8 EPROM,
just feeding back the outputs to half the inputs. Wrote a basic program
to create the Intel hex file, and within a week, had a working state
machine! (Boss thought it would take me at least a month...:cool:

Had to be careful designing the state machine to prevent race or other
glitches, and there was no such thing as a don't care! But it worked!

--
Charlie
--
Edmondson Engineering
Unique Solutions to Unusual Problems
 
John S. Dyson wrote:

In article <GY6qc.57435$iy5.289@okepread05>,
"Richard Henry" <rphenry@home.com> writes:

Coincidentally, about the same time, a friend had to redesign a digital
filter design that had been "tuned" with pots and caps all over the board.
While the engineering prototype worked flawlessly, the design did not
survive the transfer to production.


I thought that I was the only person to experience such silly design
techniques (luckily, I fixed the design before production.) The
circuit was developed in the 1977 timeframe, and used the old
4116 type DRAMs. Those devices required a fairly well controlled
RAS/CAS delay, and the 6502 processor (1MHz, 2MHz clocked at 1MHz
later on) didn't have well specified clock-in vs effective I/O
clock delays... The external clock generator versions of the 6502s
did have a specified I/O clock delay, but we weren't able to use
that for various reasons (that I don't remember.) Unfortunately,
the original hack design used
a resistor and gate threshold and capacitance to effect the RAS
to CAS delay!!! The original (happily aborted) production design
even had a POT to effect a RAS/CAS delay tweak!!! Well, when I finally
won the argument that the quality of the product would suffer (in
fact, the environment was industrial, so not well
controlled), I 'solved' the problem with a brute force
delay line. If I wasn't so pressured by time, I might have
re-considered a high speed clocked approach, but the delay line
did minimize parts count and guaranteed a 'works first time'
result. (The clocked version also had some precision issues,
due to the timing margins, but I probably could have gotten
it to work reliably given a week or so of design time.)

Anyway, the need for redesign did cause a dust-up at work, but
we really needed to produce a reliable design. The RC and
gate threshold delay was so unstable, that even our lab versions
of the DRAM board needed to be 'readjusted' periodically. I
couldn't convince the original engineer that such 'readjustments'
would be even worse in the field. I even tried to offer him
the opportunity for owning the fix, but somehow his ego got
involved OR he wanted to see some kind of failure?!??!

John

Back in my old toll road days, we had a problem with long signal lines
getting noise! There would be lots of little 1ms spikes on the inputs
causing false triggers on our digital I/O boards, which drove us nuts!
We tried RC filters, one-shots, you name it, but some of these things
just kept getting through.

Our solution involved using MC 14990 (I think that is right) debounce
chips in our data path. These filtered out the noise very nicely, and
gave us nice, clean outputs, even if they were now delayed a few ms. My
boss even designed and produced special buffer boards using these and
some optos mounted in 2U rack mount we used them so much!

--
Charlie
--
Edmondson Engineering
Unique Solutions to Unusual Problems
 
John Larkin wrote:

On Mon, 17 May 2004 13:41:25 GMT, Fred Bloggs <nospam@nospam.com
wrote:


I am on the verge of hbp and sometimes get non-stop arrhythmia if I miss
doing exercise- but if I exercise there is no problem and no afternoon
slump. You have to make the exercise burn- and run the heart rate up-
the best resistance movements are the large muscle group strainers: full
squats, presses, and dead lifts- would not waste time on the designer
junk like curls and raises- the best abdominal exercise is the
knee-tuck-crunch while suspended from parallel bars- I almost never do
situps or regular crunches- and those parallel bar things- maybe a dozen
daily- keep my abs strong enough to easily do a regular crunch with 150
lbs barbell plates stacked on my chest. If you go to it and keep moving-
you can get an excellent workout in about 30 minutes and be done with
it- but cardio must be done daily.


I just park about 9 blocks, roughly 500 vertical feet, from work. The
hike uphill at the end of the day is mandatory... there's no way to
skip it short of sleeping over at work. The scenery is distracting
from the essential boredom of getting exercize.

High bp is a killer, and I see no reason not to do whatever it takes -
exercize, diet, drugs - to see as much of the future as possible.

John


I just take a 1 hour pilates class twice a week. And of course, right
now, I am pouring a patio, 6 60lb bags of concrete at a time...

Atkins, of course, help me loose 25 pounds, and get my triglycerides
down. Quit doing drugs a couple of years ago when my doc and the
pharmacy couldn't get the dosages straight.

--
Charlie
--
Edmondson Engineering
Unique Solutions to Unusual Problems
 

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