RE: [newbie] clock help
How about this: an external box connected to an AC outlet, inside an optocoupler with schmitt-trigger(sp?) and a connector for a serial cable? Connect to a spare serial port on your PC, you could get a nice TTL signal on one of the readable pins on the port. That's a nice idea. Give it an IEC plug and socket and it would go between the PC and the AC outlet. In fact it is so simple that it might fit into an IEC plug or socket housing, but those things are a tight fit already. If you could get away without a schmitt-trigger you wouldn't need a power supply for it. Having two opto-isolators each sensitive to a different half-phase would mean you could do the debounce in software: On CTS irq: disable CTS irq, enable DSR irq On DSR irq: disable DSR irq, enable CTS irq It also gives you a 100Hz clock. -- Richard Urwin, Private No 9000 series computer has ever made a mitsake or corrubiteddatatato. This email has been scanned for all viruses by the MessageLabs SkyScan service. For more information on a proactive anti-virus service working around the clock, around the globe, visit http://www.messagelabs.com Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
RE: [newbie] clock help
The suggestion is not entirely out-to-lunch. Computers certainly used to use the line frequency for the real-time clock; the PDP-11 comes to mind. In fact the line frequency is a better solution than crystal because, at least here in the UK, the _average_ line frequency is guaranteed to be 50Hz to a very high precision - much better than a crystal. This is achieved by adjusting the short-term line frequency to correct accumulated errors. My old bed-side alarm clock used line frequency and it never needed adjusting except for power-cuts and summer time. You would, of course transform it down to a lower voltage first, but nobody suggested otherwise. It wouldn't blow up a motherboard just because it was AC. In fact it would be dead simple to design a PC board to take a feed from the AC and provide a Linux driver with a 50/60Hz signal. The hardest bit would be getting the AC feed from the self-contained power supply. Does the GMT/LOCALTIME mismatch solve the problem? If so the clock errors would all be of the form Damn! The clock is off by exactly an hour again! (or three hours...) And first in one direction (using Linux) and then the other (using Windows.) Neither of these actually alter the hardware clock unless you tell it to, except for summer time, which is topical right now, but each OS should only ever do it once and only by an hour. If it is ever off by some minutes and seconds GMT/LOCALTIME is not the answer. It can only make errors of whole numbers of hours. -- Richard Urwin, Private No 9000 series computer has ever made a mitsake or corrubiteddatatato. -Original Message- From: [EMAIL PROTECTED] [mailto:newbie-owner;linux-mandrake.com]On Behalf Of Lyvim Xaphir Sent: 03 November 2002 21:02 To: NewbieMandrake-List Subject: Re: [newbie] clock help On Fri, 2002-11-01 at 15:31, Frans Ketelaars wrote: Uhm, I don't think the power line frequency has anything to do with timing in computers like PC's that use crystals for timing :) That is correct. 60 cycle ac is rectified and filtered to 12 and 5 volt DC current in the power supply; that is it's purpose. The motherboards have no exposure whatsoever to AC utility current (and would be destroyed if they did). Mobos source their clock signal from a quartz crystal IC, or in some cases electrical IC's generate clock signals without the help of a crystal; although I've been given to understand that the latter is not as accurate or stable a method. The clock case here in this thread is probably an instance of the hardware clock being set to GMT instead of LOCAL time. As David Rankin suggested. On Fri, 01 Nov 2002 08:59:46 -0500 Bob Read [EMAIL PROTECTED] wrote: Sounds like the system clock is set for 50Hz power line frequency, and you are using 60Hz power line. Bob l8r, LX -- °°° Kernel 2.4.18-6mdk Mandrake Linux 8.2 Enlightenment 0.16.5-11mdkEvolution 1.0.2-5mdk Registered Linux User #268899 http://counter.li.org/ °°° This email has been scanned for all viruses by the MessageLabs SkyScan service. For more information on a proactive anti-virus service working around the clock, around the globe, visit http://www.messagelabs.com Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [newbie] clock help
On Mon, 4 Nov 2002 13:42:08 - Richard Urwin [EMAIL PROTECTED] wrote: The suggestion is not entirely out-to-lunch. Computers certainly used to use the line frequency for the real-time clock; the PDP-11 comes to mind. In fact the line frequency is a better solution than crystal because, at least here in the UK, the _average_ line frequency is guaranteed to be 50Hz to a very high precision - much better than a crystal. This is achieved by adjusting the short-term line frequency to correct accumulated errors. My old bed-side alarm clock used line frequency and it never needed adjusting except for power-cuts and summer time. AFAIK the same system is used in the Netherlands. Indeed I had a digital alarm clock once that I'm sure used the line frequency to keep it's time. (It's microprocessor got it's clock signal from a conventional circuit I think; the microprocessor just monitored the powerline signal). It's the only way to keep accurate time if you don't have access to an accurate timing source via the internet or such to sync with now and then (or your own atomic clock :) ) You would, of course transform it down to a lower voltage first, but nobody suggested otherwise. It wouldn't blow up a motherboard just because it was AC. In fact it would be dead simple to design a PC board to take a feed from the AC and provide a Linux driver with a 50/60Hz signal. The hardest bit would be getting the AC feed from the self-contained power supply. And the most dangerous to you and your hardware :) How about this: an external box connected to an AC outlet, inside an optocoupler with schmitt-trigger(sp?) and a connector for a serial cable? Connect to a spare serial port on your PC, you could get a nice TTL signal on one of the readable pins on the port. And you could pick up the 50 / 60 Hz EMR 'out of the air' (well there should be an AC power source nearby, and it may not work inside a well shielded and grounded computer). Open spec (I hope its not patented...) hardware design and a GPL driver: now you can use line power frequency as (yet another) timing source in Linux. Oh well :-))) Does the GMT/LOCALTIME mismatch solve the problem? If so the clock errors would all be of the form Damn! The clock is off by exactly an hour again! (or three hours...) And first in one direction (using Linux) and then the other (using Windows.) Neither of these actually alter the hardware clock unless you tell it to, except for summer time, which is topical right now, but each OS should only ever do it once and only by an hour. If it is ever off by some minutes and seconds GMT/LOCALTIME is not the answer. It can only make errors of whole numbers of hours. -- Richard Urwin, Private snip I guess I got a bit of topic, sorry :) -Frans Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [newbie] clock help
On Fri, 2002-11-01 at 15:31, Frans Ketelaars wrote: Uhm, I don't think the power line frequency has anything to do with timing in computers like PC's that use crystals for timing :) That is correct. 60 cycle ac is rectified and filtered to 12 and 5 volt DC current in the power supply; that is it's purpose. The motherboards have no exposure whatsoever to AC utility current (and would be destroyed if they did). Mobos source their clock signal from a quartz crystal IC, or in some cases electrical IC's generate clock signals without the help of a crystal; although I've been given to understand that the latter is not as accurate or stable a method. The clock case here in this thread is probably an instance of the hardware clock being set to GMT instead of LOCAL time. As David Rankin suggested. On Fri, 01 Nov 2002 08:59:46 -0500 Bob Read [EMAIL PROTECTED] wrote: Sounds like the system clock is set for 50Hz power line frequency, and you are using 60Hz power line. Bob l8r, LX -- °°° Kernel 2.4.18-6mdk Mandrake Linux 8.2 Enlightenment 0.16.5-11mdkEvolution 1.0.2-5mdk Registered Linux User #268899 http://counter.li.org/ °°° Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [newbie] clock help
On Friday 01 November 2002 08:59 am, Bob Read wrote: Sounds like the system clock is set for 50Hz power line frequency, and you are using 60Hz power line. Bob if this were to happen,,, first time I ever saw a system clcok using line voltage, most every one I ever saw used mother board voltage from the power supply (that was dc). and the times i have been stupid enough to try either there was no boot up, or on bootup,,, the smoke was let out of the mother board little black smoke holders. it is a config with some part set to gmt and some part set to est. Richard Urwin wrote: Three hours a day sounds like Linux is mis-understanding some clock rate on your system. Maybe a mismatch between some motherboard part and the corresponding driver. I should check the motherboard manufacturer's web-site and do a web search with Linux and the motherboard model. Have you over-clocked the CPU? Background: The hardware clock is only used while the machine is switched off. It is too slow to use during normal running and OSs do not do so. Linux reads it at start-up and writes it at shutdown. During running OSs set up a regular interrupt and count them to keep track of the current time. -- Richard Urwin, Private No 9000 series computer has ever made a mitsake or corrubiteddatatato. -Original Message- From: [EMAIL PROTECTED] [mailto:newbie-owner;linux-mandrake.com]On Behalf Of windwalker Sent: 31 October 2002 21:06 To: [EMAIL PROTECTED] Subject: [newbie] clock help I Installed mandrake. NOW I have to reset taskbar clock twice daily !! its gaining three hours a day.. It didnt do that when I only had win 98 on box any thoughts on how to correct? Mike Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
RE: [newbie] clock help
Three hours a day sounds like Linux is mis-understanding some clock rate on your system. Maybe a mismatch between some motherboard part and the corresponding driver. I should check the motherboard manufacturer's web-site and do a web search with Linux and the motherboard model. Have you over-clocked the CPU? Background: The hardware clock is only used while the machine is switched off. It is too slow to use during normal running and OSs do not do so. Linux reads it at start-up and writes it at shutdown. During running OSs set up a regular interrupt and count them to keep track of the current time. -- Richard Urwin, Private No 9000 series computer has ever made a mitsake or corrubiteddatatato. -Original Message- From: [EMAIL PROTECTED] [mailto:newbie-owner;linux-mandrake.com]On Behalf Of windwalker Sent: 31 October 2002 21:06 To: [EMAIL PROTECTED] Subject: [newbie] clock help I Installed mandrake. NOW I have to reset taskbar clock twice daily !! its gaining three hours a day.. It didnt do that when I only had win 98 on box any thoughts on how to correct? Mike This email has been scanned for all viruses by the MessageLabs SkyScan service. For more information on a proactive anti-virus service working around the clock, around the globe, visit http://www.messagelabs.com Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [newbie] clock help
Sounds like the system clock is set for 50Hz power line frequency, and you are using 60Hz power line. Bob Richard Urwin wrote: Three hours a day sounds like Linux is mis-understanding some clock rate on your system. Maybe a mismatch between some motherboard part and the corresponding driver. I should check the motherboard manufacturer's web-site and do a web search with Linux and the motherboard model. Have you over-clocked the CPU? Background: The hardware clock is only used while the machine is switched off. It is too slow to use during normal running and OSs do not do so. Linux reads it at start-up and writes it at shutdown. During running OSs set up a regular interrupt and count them to keep track of the current time. -- Richard Urwin, Private No 9000 series computer has ever made a mitsake or corrubiteddatatato. -Original Message- From: [EMAIL PROTECTED] [mailto:newbie-owner;linux-mandrake.com]On Behalf Of windwalker Sent: 31 October 2002 21:06 To: [EMAIL PROTECTED] Subject: [newbie] clock help I Installed mandrake. NOW I have to reset taskbar clock twice daily !! its gaining three hours a day.. It didnt do that when I only had win 98 on box any thoughts on how to correct? Mike -- Bob Read // Registered Linux user #287118 http://www.cyberhymnal.org/htm/b/e/bestill.htm Soli Deo Gloria-Solus Christus-Sola Gratia-Sola Fide-Sola Scriptura The Church of The Master [Baptist] Providence, Rhode Island http://users.ids.net/~bobread/cotm.htm Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [newbie] clock help
Uhm, I don't think the power line frequency has anything to do with timing in computers like PC's that use crystals for timing :) On Fri, 01 Nov 2002 08:59:46 -0500 Bob Read [EMAIL PROTECTED] wrote: Sounds like the system clock is set for 50Hz power line frequency, and you are using 60Hz power line. Bob Richard Urwin wrote: Three hours a day sounds like Linux is mis-understanding some clock rate on your system. Maybe a mismatch between some motherboard part and the corresponding driver. I should check the motherboard manufacturer's web-site and do a web search with Linux and the motherboard model. Have you over-clocked the CPU? Background: The hardware clock is only used while the machine is switched off. It is too slow to use during normal running and OSs do not do so. Linux reads it at start-up and writes it at shutdown. During running OSs set up a regular interrupt and count them to keep track of the current time. -- Richard Urwin, Private No 9000 series computer has ever made a mitsake or corrubiteddatatato. -Original Message- From: [EMAIL PROTECTED] [mailto:newbie-owner;linux-mandrake.com]On Behalf Of windwalker Sent: 31 October 2002 21:06 To: [EMAIL PROTECTED] Subject: [newbie] clock help I Installed mandrake. NOW I have to reset taskbar clock twice daily !! its gaining three hours a day.. It didnt do that when I only had win 98 on box any thoughts on how to correct? Mike -- Bob Read // Registered Linux user #287118 HTH, -Frans Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
