Re: [SLE] [Fwd: [SLE] microsecond clock timer]
Message-ID: <3A369A80.DB89B6FA@computer.org>
Date: Tue, 12 Dec 2000 21:37:04 +0000
From: Garry Smith
I have been given a microsecond clock .dll for Windows (which I have yet I am also working with Windows and would very much like to know about this dll that you mentioned. Where did you find it? Can you tell me more about it?
I know very little about it. I got it from a collegue who in turn was given it by someone at Microsoft. I have asked him if he has any documentation for it but it does not appear that he has. You can pick it up from http://www.sis.port.ac.uk/~mab/TOPIC/Java/Clock.dll
interesting to see if Windows can manage a finer granularity.
Haven't had a chance to do the programming in Linux yet but the program I am working with uses a hardware card that just happens to have a microsecond timer on it and I am able to use that but I don't want to depend on this and would rather use something that is part of the computer
What is this hardware card? If it works under Linux that could be a way to solve my problem. Do you have a url pointing to more information for it? Any idea of the cost? In terms of timing under Linux I had the suggestion earlier of using ticks and just summing them. Does anyone have any thoughts on this? Any ideas how I read these ticks? regards Garry
Date: Tue, 12 Dec 2000 17:01:11 -0500
From: Damon Register
documentation for it but it does not appear that he has. I got it from the link that you provided but it doesn't even show any info with Quickview.
What is this hardware card? If it works under Linux that could be a way The card is a MIL-STD-1553 bus interface card. I keep bugging then for Linux drivers but I think it hasn't been done yet.
to solve my problem. Do you have a url pointing to more information for http://www.mil-1553.com
it? Any idea of the cost? $4800. The main purpose of this card is 1553 interface and the timer just happened to be a fringe benefit for me. This would almost certainly not be of any value for what you are doing. Likely there are other hardware options that are more suitable for you. I remember that some flight test people here were using some sort of time generator card in the PCs they were using to
collect flight data
ticks and just summing them. Does anyone have any thoughts on this? Any If it is anything like the ticks that Windows uses, they aren't very
precise so that is why I am using the alternate hardware timer. I remember somewhere around 7 years ago I was working with a DOS program that was able to read a hardware clock chip to get microsecond precision. I never tried that in the 32 bit Windows environment or in Linux but perhaps you could adapt the code? The above mentioned clock chip seems to be a standard part of an Intel class PC. If you would like, I can try to dig up that DOS C code and you could try to adapt it. Damon Register
From: Neal Eldred
I remember somewhere around 7 years ago I was working with a DOS program that was able to read a hardware clock chip to get microsecond precision. I never tried that in the 32 bit Windows environment or in Linux but perhaps you could adapt the code? The above mentioned clock chip seems to be a standard part of an Intel class PC. If you would like, I can try to dig up that DOS C code and you could try to adapt it.
Also from that era: Michael Abrash's _Zen_of_Code_Optimization_
(Coriolis, 1994), which contained asm code for a microsecond timer
for intervals up to 54 milliseconds. The code manipulated one of the
three timers on an Intel 8253 chip. Interrupts had to be turned off
while the timer was running. That's okay in DOS, but wouldn't this
be a problem in Linux? (I haven't had a chance to do much with Linux,
yet -- still walking on eggshells when I run it)
<p>
--
Neal Eldred
Also from that era: Michael Abrash's _Zen_of_Code_Optimization_ (Coriolis, 1994), which contained asm code for a microsecond timer for intervals up to 54 milliseconds. The code manipulated one of the three timers on an Intel 8253 chip. Interrupts had to be turned off That's it, I think. This sounds very familiar. I didn't know of
while the timer was running. That's okay in DOS, but wouldn't this be a problem in Linux? (I haven't had a chance to do much with Linux, If anyone has the answer to that, I would like to know. Will Linux
Date: Thu, 14 Dec 2000 06:58:34 -0500
From: Damon Register
Message-ID: <3A36A199.49B0F90F@compro.net>
Date: Tue, 12 Dec 2000 17:07:21 -0500
From: Mark Hounschell
Hi Damon,
I have been given a microsecond clock .dll for Windows (which I have yet I am also working with Windows and would very much like to know about this dll that you mentioned. Where did you find it? Can you tell me more about it?
I know very little about it. I got it from a collegue who in turn was given it by someone at Microsoft. I have asked him if he has any documentation for it but it does not appear that he has.
You can pick it up from http://www.sis.port.ac.uk/~mab/TOPIC/Java/Clock.dll
interesting to see if Windows can manage a finer granularity.
Haven't had a chance to do the programming in Linux yet but the program I am working with uses a hardware card that just happens to have a microsecond timer on it and I am able to use that but I don't want to depend on this and would rather use something that is part of the computer
What is this hardware card? If it works under Linux that could be a way to solve my problem. Do you have a url pointing to more information for it? Any idea of the cost?
In terms of timing under Linux I had the suggestion earlier of using ticks and just summing them. Does anyone have any thoughts on this? Any ideas how I read these ticks?
You might have a look at this. It's not ready for linux be we are doing the port and will probably be done in next few months. http://www.encore.com/products/software/osenhanc/980058.shtml#hw -- Mark Hounschell markh@compro.net
participants (4)
-
damon.w.register＠lmco.com -
Garry.Smith＠computer.org -
markh＠compro.net -
neldred＠qwest.net