Just type SYS 64738.
My machine used RAND USR 0
5 ways to reboot a PC. None of them reliable.
11–20 of 35 posts
Re: 5 ways to reboot a PC. None of them reliable.
#12It amazes me that this sort of behavior still hasn't been standardized and agreed upon by all PC and component manufacturers.
Reality is that in areas of poor standardisation, vendors will test against Windows and ship it if it works. You could argue for a cross-vendor compliance testing suite, but if the behaviour of Windows varied from that then people would still need to match the Windows behaviour because that's where the market is. So for all practical purposes, the behaviour is standardised. It's just embodied in the behaviour of Wind…
The behavior is standardized to a degree that it works for Windows, but according to your article Windows does its own poking around for the reset. It would be nice if there was one established protocol for resets rather than any poking around at all.
I guess this was the point of your article though.
Re: 5 ways to reboot a PC. None of them reliable.
#13[deleted]
Re: 5 ways to reboot a PC. None of them reliable.
#14Was there ever a computer as ugly as the IBM-PC? I imagine even the Commodore 16 could reboot itself reliably.
An actual IBM-PC could reliably be rebooted using the keyboard controller (as mentioned in the article). The issues come with IBM-PC "compatible" machines. I'm sure commodore would have the same problem if anyone had bothered to clone them.
Re: 5 ways to reboot a PC. None of them reliable.
#15Method 6: return to 16-bit mode, call interrupt 0x19 (not if you're on efi). Method 7: return to 16-bit mode, set cs to 0xf000 and jump to 0xfff0. Linux used to use method 6, but it wasn't reliable either. Something tells me returning to 16-bit mode might not be possible for some hardware / driver combinations.
Could you explain in more detail how these trigger a reboot? From writing a 32-bit kernel I understand how the triple fault method is supposed to work, for example, but would love to know a little more about these methods.
Re: 5 ways to reboot a PC. None of them reliable.
#16I don't know if anyone else remembers, but I think it was either Windows 95 or Windows 98 which, after selecting shut down, the eventual result would be a message that said, "It is now safe to turn off your computer." I remember thinking it was magic when the computer would actually turn itself off at this point.
This article provides a good explanation for why that behavior was necessary.
Re: 5 ways to reboot a PC. None of them reliable.
#17It amazes me that this sort of behavior still hasn't been standardized and agreed upon by all PC and component manufacturers.
Reality is that in areas of poor standardisation, vendors will test against Windows and ship it if it works. You could argue for a cross-vendor compliance testing suite, but if the behaviour of Windows varied from that then people would still need to match the Windows behaviour because that's where the market is. So for all practical purposes, the behaviour is standardised. It's just embodied in the behaviour of Wind…
FWIW, the fact that it's standardized against Windows makes Windows kernel developers' lives suck too - any change can break some dumb device that only actually worked purely by coincidence against XP SP1 or some ancient version
Re: 5 ways to reboot a PC. None of them reliable.
#18Was there ever a computer as ugly as the IBM-PC? I imagine even the Commodore 16 could reboot itself reliably.
An actual IBM-PC could reliably be rebooted using the keyboard controller (as mentioned in the article). The issues come with IBM-PC "compatible" machines. I'm sure commodore would have the same problem if anyone had bothered to clone them.
To be more precise, an IBM PC-AT. It is closely related to the A20 line enable.
Re: 5 ways to reboot a PC. None of them reliable.
#19I don't know if anyone else remembers, but I think it was either Windows 95 or Windows 98 which, after selecting shut down, the eventual result would be a message that said, "It is now safe to turn off your computer." I remember thinking it was magic when the computer would actually turn itself off at this point. This article provides a good explanation for why that behavior was necessary.
Power off uses APM or ACPI and is not related.
Re: 5 ways to reboot a PC. None of them reliable.
#20It amazes me that this sort of behavior still hasn't been standardized and agreed upon by all PC and component manufacturers.
Reality is that in areas of poor standardisation, vendors will test against Windows and ship it if it works. You could argue for a cross-vendor compliance testing suite, but if the behaviour of Windows varied from that then people would still need to match the Windows behaviour because that's where the market is. So for all practical purposes, the behaviour is standardised. It's just embodied in the behaviour of Wind…
I think that the other issue is the culture around(and design) *nix and BSD systems, where a reboot is generally only done when very bad things happen to the system, and nothing else can correct it. Often, there are a lot of other things going on that prevent the system from gracefully rebooting.
So hardware vendors might test a "standard" reboot, where nothing is broken, and the OS is in a stable state. Unfortunately, that probably isn't the case where most required reboots occur.