On 2010.11.9 8:24 PM, Joshua Juran wrote: > On Nov 9, 2010, at 12:40 PM, Michael G Schwern wrote: > >> On 2010.11.9 9:31 AM, Joshua Juran wrote: >>> Dual-booting OS 9 and OS X demonstrates OS X using local time as well. I >>> don't know what happens on Macs that can't boot classic Mac OS. >> >> I can assure you OS X is using a UTC clock. > > Of course it is. But I suspect it's storing local time in the clock chip.
That would be the opposite of using a UTC clock. I doubt it's doing that on Intel, it doesn't make any sense for it to do so. They never made an Intel version of OS 9, right? I wouldn't be surprised if as part of the prep Apple did for OS 9 to work inside OS X they changed how it stores time in the hardware and left the OS 9 APIs to do the localization. >> I used to see problems dual booting between Windows XP and Linux until they >> somehow figured out how to live together. It's unlikely Apple put in the >> effort to make OS 9 and OS X dual boot well. > > Quite the contrary. Apple went to considerable effort to make OS 9 and OS X > interoperable, to encourage users and developers to switch to the new > platform. The Carbon API was created in response to developer backlash > against being forced to rewrite everything for OS X (using Cocoa). I was referring specifically to dual booting, I recall they did a lot of work on OS 9. Anyhow, my brain has buried most knowledge of OS 9 in layers of rich caramel nougat. > Short answer: I write code targeting classic Mac OS, and the closed-source > developer tools I rely on depend on it. Ouch. >> You're right that OS 9 uses local time, even their *epoch* (1904) is in local >> time. I found an interesting snippet about it on >> http://calendars.wikia.com/wiki/Epoch_%28reference_date%29 (did YOU know >> there's a wiki about calendaring?) >> >> January 1, 1904, was chosen as the base for the Macintosh clock because >> it was the first leap year of the twentieth century. [...] This means >> that by starting with 1904, Macintosh system programmers could save a >> half dozen instructions in their leap-year checking code, which they >> thought was way cool. > > It also spares Mac OS the Year 2038 problem. Instead, it has a Year 2040 > problem. I still have my Mac SE in working condition. I will boot it in 2039 just to cheese off the rest of the world. -- 60. "The Giant Space Ants" are not at the top of my chain of command. -- The 213 Things Skippy Is No Longer Allowed To Do In The U.S. Army http://skippyslist.com/list/
