jiffy timer
Jeff Robertson
All these trivia questions about old Commodore stuff makes me wonder -
('Stairway to Heaven' playing in background...)
Was Commodore the only company to use the word 'jiffy' to mean a cycle
of the clock ? The C64 literature said that a 'jiffy' was 1/64 seconds.
The clock was therefore refferred to as the 'jiffy timer'.
Has anybody heard of this usage of 'jiffy' outside of Commdore ?
Jeff Robertson <jrob...@ua1ix.ua.edu>, <jrob...@ua1vm.ua.edu>
GCS/MU/O -d+ -p+ c++ u+ e+ m* s+/-- n--- h-- f@ g@ w+ t++ y-(*)
-----
Either CONFESS now or we go to ``PEOPLE'S COURT''!!
--- Zippy the Pinhead
Sarr J. Blumson
jrob...@ua1ix.ua.edu (Jeff Robertson) writes:
|>
|> Was Commodore the only company to use the word
|> 'jiffy' to mean a cycle
|> of the clock ? The C64 literature said that a
|> 'jiffy' was 1/64 seconds.
|> The clock was therefore refferred to as the
|> 'jiffy timer'.
|>
(1964(, where a "jiffy" was
1/60 second in North America, or 1/50 second in
Europe.
Guess how they generated it?
--
--------
Sarr Blumson sa...@citi.umich.edu
voice: +1 313 764 0253 home: +1 313 665 9591
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Duncan Rowland
Jeff Robertson <jrob...@ua1ix.ua.edu> wrote:
>[ . . . ]
>Has anybody heard of this usage of 'jiffy' outside of Commdore ?
As a side track, there was/is a make of condom named 'jiffy' which was
advirtised with the slogan 'real men come in a jiffy'. Please feel free to
ignore this week attempt at humor.
-Duncan.
Pat St. Jean
: All these trivia questions about old Commodore stuff makes me wonder -
: ('Stairway to Heaven' playing in background...)
: Was Commodore the only company to use the word 'jiffy' to mean a cycle
: of the clock ? The C64 literature said that a 'jiffy' was 1/64 seconds.
: The clock was therefore refferred to as the 'jiffy timer'.
: Has anybody heard of this usage of 'jiffy' outside of Commdore ?
Linux uses jiffies in the kernel as 1/100 of a second.
--Pat
===========================================================================
Pat St. Jean stj...@math.enmu.edu
Eastern New Mexico University Systems Administrator
===========================================================================
Linux developer who is more than willing to pay for programs
if by doing so I can encourage more development.
===========================================================================
Jeff Robertson
: : Was Commodore the only company to use the word 'jiffy' to mean a cycle
: : of the clock ? The C64 literature said that a 'jiffy' was 1/64 seconds.
: : The clock was therefore refferred to as the 'jiffy timer'.
: : Has anybody heard of this usage of 'jiffy' outside of Commdore ?
: Linux uses jiffies in the kernel as 1/100 of a second.
When I said that a Commodore jiffy was 1/64 of a second, that was a typo
or a memory lapse or something. Its 1/60. Not that anybody cares.
Jeff Robertson <jrob...@ua1ix.ua.edu>, <jrob...@ua1vm.ua.edu>
GCS/MU/O -d+ -p+ c++ u+ e+ m* s+/-- n--- h-- f@ g@ w+ t++ y-(*)
-----
On the road, ZIPPY is a pinhead without a purpose, but never
without a POINT.
--- Zippy the Pinhead
Dave Carrigan
>advirtised with the slogan 'real men come in a jiffy'. Please feel free to
>ignore this week attempt at humor.
I'm still ignoring last week's attempt at humor.
--
Dave Carrigan (da...@dave.nofc.forestry.ca)
Yow! Thousands of days of civilians ... have produced a...
feeling for the aesthetic modules --
Lennart Benschop
Jeff Robertson <jrob...@ua1ix.ua.edu> wrote:
>When I said that a Commodore jiffy was 1/64 of a second, that was a typo
>or a memory lapse or something. Its 1/60. Not that anybody cares.
It's 1/60 second in the U.S. (and other countries with a 60fps TV standard)
and 1/50 second in Europe (and other regions with 50fps TV standard). The
Jiffy timer is coupled to the video circuitry and generates interrupts at
the beginning of each frame. In fact the video circuit needs to generate the
signal anyway and it needs only be made accessible and be connected to the
interrupt pin of the CPU. You could revector that interrupt and use it for
all kinds of interesting graphical effects.
Many (or most) home computers (like the ZX Spectrum) have a similar tmer.
Lennart.
Tommy Usher
>All these trivia questions about old Commodore stuff makes me wonder -
>('Stairway to Heaven' playing in background...)
>Was Commodore the only company to use the word 'jiffy' to mean a cycle
>of the clock ? The C64 literature said that a 'jiffy' was 1/64 seconds.
>The clock was therefore refferred to as the 'jiffy timer'.
>Has anybody heard of this usage of 'jiffy' outside of Commdore ?
No, Commodore wasn't the only one, and they were probably not the first.
This term was very common in Atari documentation, and since the Atari
400 and 800 came out before the C=64, it probably originated with Atari.
In fact, the Jargon File gives a broader definition:
:jiffy: n. 1. The duration of one tick of the system clock on the
computer (see {tick}). Often one AC cycle time (1/60 second in
the U.S. and Canada, 1/50 most other places), but more recently
1/100 sec has become common. "The swapper runs every 6 jiffies"
means that the virtual memory management routine is executed once
for every 6 ticks of the clock, or about ten times a second.
2. Confusingly, the term is sometimes also used for a 1-millisecond
{wall time} interval. Even more confusingly, physicists
semi-jokingly use `jiffy' to mean the time required for light to
travel one foot in a vacuum, which turns out to be close to one
*nanosecond*. 3. Indeterminate time from a few seconds to
forever. "I'll do it in a jiffy" means certainly not now and
possibly never. This is a bit contrary to the more widespread use
of the word. Oppose {nano}. See also {Real Soon Now}.
---
. QMPro 1.51 . IBM really means Insidious Byzantine Mentality
Jerome Yuzyk
-> : All these trivia questions about old Commodore stuff makes me wonder -
-> : ('Stairway to Heaven' playing in background...)
-> : Was Commodore the only company to use the word 'jiffy' to mean a cycle
-> : of the clock ? The C64 literature said that a 'jiffy' was 1/64 seconds.
-> : The clock was therefore refferred to as the 'jiffy timer'.
-> : Has anybody heard of this usage of 'jiffy' outside of Commdore ?
-> Linux uses jiffies in the kernel as 1/100 of a second.
If you're not too picky about "anybody," I believe cosmologists use the
term jiffy to indicate the amount of time between T0 (the beginning of
the universe) and the furthest back their models model. Last I read it
was something like 10^^-23 seconds.
.-^-.-^-.-^-.-^-.-^-.-^-.-^-.-^-.-^-.-^-.-^-.-^-.-^-.-^-.-^-.-^-.-^-.
Jerome Yuzyk jerome...@freddy.supernet.ab.ca
BRIDGE Scientific Services Edmonton Alberta Canada
* RM 1.3 00857 * For every problem there's a clear, obvious solution that's t
David Thomas Richard Given
Lennart Benschop <len...@blade.stack.urc.tue.nl> wrote:
>In article <1994Apr16.1...@ua1ix.ua.edu>,
>Jeff Robertson <jrob...@ua1ix.ua.edu> wrote:
>It's 1/60 second in the U.S. (and other countries with a 60fps TV standard)
>and 1/50 second in Europe (and other regions with 50fps TV standard). The
>Jiffy timer is coupled to the video circuitry and generates interrupts at
>the beginning of each frame. In fact the video circuit needs to generate the
Well, I first heard of a jiffy from my old school's CBM Pet (now dead, alas,
due to a ten-year old, a hammer, and the missing screws that didn't hold the
lid down). On that, it was 1/60 sec. Presumably the built-in monitor also
worked at 60 Hz... interesting circuitry for converting. The Commodore 64
was very nearly identical in terms of the OS and low-level hardware (it just
had a few things grafted on like the memory paging and the video controller).
In fact, Commodore Basic was *INFERIOR* to Basic 4 on the CBM Pet. How's that
for moving with the times?
--
__ _ _ _ _ | GCS -d+(?)(++) p(-+)(---) c++++ !l(-)
| \ /_\ || | | \ / | || |_ |\ | | u(+) e*(++) m*(++) s !n h+(++) f+ g+
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dt...@st-andrews.ac.uk | ***In search of better V's***
Mark Anderson
> -> : All these trivia questions about old Commodore stuff makes me wonder -
> -> : ('Stairway to Heaven' playing in background...)
> -> : Was Commodore the only company to use the word 'jiffy' to mean a cycle
> -> : of the clock ? The C64 literature said that a 'jiffy' was 1/64 seconds.
> -> : The clock was therefore refferred to as the 'jiffy timer'.
> -> : Has anybody heard of this usage of 'jiffy' outside of Commdore ?
> -> Linux uses jiffies in the kernel as 1/100 of a second.
> If you're not too picky about "anybody," I believe cosmologists use the
> term jiffy to indicate the amount of time between T0 (the beginning of
> the universe) and the furthest back their models model. Last I read it
> was something like 10^^-23 seconds.
And, of course, there's the traditional saying (in the UK, anyway)
"I'll be back in a jiffy" meaning I will return in a short time. :-)
Mark.
Tommy Hallgren
LB> It's 1/60 second in the U.S. (and other countries with a 60fps TV
LB> standard) and 1/50 second in Europe (and other regions with 50fps TV
LB> standard). The Jiffy timer is coupled to the video circuitry and
LB> generates interrupts at the beginning of each frame.
The C64 jiffy-timer has nothing to do with the VBL. It's 60Hz on my 64 here.
(And don't argue since I'm a C64-vet. ;-)
Glada v.rh.lsningar fr.n Tommy - internet: to...@flower.ct.se
... MS-Windows NyaTestamentet - .ntligen ett Kristet OS!!! :^)
Richard Shuford
first applied to the reckoning of computer time in the pioneering
Multics operating system.
The usual references on Multics are as follows:
Organick, E.I. \The Multics System/. Cambridge, MA: MIT Press, 1972.
Corbato, F.J., Saltzer, J.H., and Clingen, C.T. "Multics--the First
Seven Years," \Proceedings of the AFIPS Spring Joint Computer
Conference/, pp. 571-583, 1972.
Corbato, F.J., Vyssotzky, V.A. "Introduction and Overview of the
Multics System," \Proceedings of the AFIPS Fall Joint Computer
Conference/, pp. 185-196, 1965.
(I don't have any of these at hand, or I'd check.)
--
...Richard S. Shuford | "Like one who seizes a dog by the ears is a
...shu...@cs.utk.edu | passer-by who meddles in a quarrel not his own."
...Info-Stratus contact| Proverbs 26:17 NIV
Geoff McCaughan
>If you're not too picky about "anybody," I believe cosmologists use the
>term jiffy to indicate the amount of time between T0 (the beginning of
>the universe) and the furthest back their models model. Last I read it
>was something like 10^^-23 seconds.
If they ever get this to <10^^42, give me a call.
8-)
--
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"The silver thorn, the bloody rose, lying crushed upon the virgin snow"
Vote SPQR Ski Nix Olympica Freedom for Axolotls
Steve Ketcham
jerome...@freddy.supernet.ab.ca (Jerome Yuzyk) wrote:
>
>
> -> : All these trivia questions about old Commodore stuff makes me wonder -
> -> : ('Stairway to Heaven' playing in background...)
>
> -> : Was Commodore the only company to use the word 'jiffy' to mean a cycle
> -> : of the clock ? The C64 literature said that a 'jiffy' was 1/64 seconds.
> -> : The clock was therefore refferred to as the 'jiffy timer'.
>
Steve Ketcham Steve_...@vos.stratus.com
Senior Technical Consultant Phone: (508) 460-2377
Stratus Computer, Inc FAX: (508) 480-0067
55 Fairbanks Blvd
Marlboro, MA 01752 I speak for myself, not Stratus.
Ian Kemmish
>In article <50.25924.7...@freddy.supernet.ab.ca>,
>jerome...@freddy.supernet.ab.ca (Jerome Yuzyk) wrote:
>>
>>
>> -> : All these trivia questions about old Commodore stuff makes me wonder -
>> -> : ('Stairway to Heaven' playing in background...)
>>
>> -> : Was Commodore the only company to use the word 'jiffy' to mean a cycle
>> -> : of the clock ? The C64 literature said that a 'jiffy' was 1/64 seconds.
>> -> : The clock was therefore refferred to as the 'jiffy timer'.
>>
>Stratus uses it in VOS (their proprietary OS) to mean 1/65536 sec.
>
One of my supervisors at university (Maths....) used it to mean
1.0e-43 seconds. (To be honest, I can't remember if 43 was
the *exact* exponent, but it doesn't seems to matter that much,
unles you're into cosmology:->).
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Juan Molinari
>One of my supervisors at university (Maths....) used it to mean
>1.0e-43 seconds. (To be honest, I can't remember if 43 was
>the *exact* exponent, but it doesn't seems to matter that much,
>unles you're into cosmology:->).
What is this, the amount of time it takes for light to traverse
the head of a pin? :-)
--
____ Juan G. Molinari (716) 475-3643
\HI/ ju...@clark.net Rochester, NY
\/ Suicide is our way of saying to God:
"You can't fire me! I QUIT!"
Wilson Roberto Afonso
>ia...@tdc.dircon.co.uk (Ian Kemmish) writes:
>>One of my supervisors at university (Maths....) used it to mean
>>1.0e-43 seconds. (To be honest, I can't remember if 43 was
>>the *exact* exponent, but it doesn't seems to matter that much,
>>unles you're into cosmology:->).
> What is this, the amount of time it takes for light to traverse
> the head of a pin? :-)
The amout of time (counting from the beginning of the universe) after which
science knows something (if I am not too confused).
-Wilson
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Lon Stowell
>ia...@tdc.dircon.co.uk (Ian Kemmish) writes:
>>One of my supervisors at university (Maths....) used it to mean
>>1.0e-43 seconds. (To be honest, I can't remember if 43 was
>>the *exact* exponent, but it doesn't seems to matter that much,
>>unles you're into cosmology:->).
> What is this, the amount of time it takes for light to traverse
> the head of a pin? :-)
>
theory--also the typical attention span of a journalist or
politician.
Geoff McCaughan
>ia...@tdc.dircon.co.uk (Ian Kemmish) writes:
>>One of my supervisors at university (Maths....) used it to mean
>>1.0e-43 seconds. (To be honest, I can't remember if 43 was
>>the *exact* exponent, but it doesn't seems to matter that much,
>>unles you're into cosmology:->).
> What is this, the amount of time it takes for light to traverse
> the head of a pin? :-)
Nope, it's the Planck time. A time quanta.