Archived posting to the Leica Users Group, 1999/12/04

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Subject: Re: [Leica] more OT computer nonsense
From: Godfrey DiGiorgi <ramarren@bayarea.net>
Date: Sat, 4 Dec 1999 08:46:47 -0800

I hate seeing inaccurate information disseminated as fact. 

>A small case in point: Unix machines have adjusted the time automatically
>for Daylight Savings for a long time now. I'm not sure what version of
>Unix would have had this, but let's say it was introduced around 1980.
>That would not be far off, plus or minus 3 years.
>
>My "modern" Macintosh still needs to be manually updated. ...

This is incorrect.

Mac OS 8.0 and above allows options in automating daylight savings time 
and network time server updating. Open the "Date and Time" control panel, 
you'll see the user interface to these services. It's been a long time 
since I ran Mac OS 7.x, but I believe that at least the daylight savings 
time automation has been in the system since Mac OS 7. That's back to 
1991 or so. All Macintosh computers, since introduction in 1984, have 
built-in, battery-powered quartz clocks and system time management 
functions available to the applications, even in the earliest versions of 
the operating system, so such automation could have been provided on the 
earliest machines but wasn't for the usual reasons of resource 
constraints and business priorities. Many small utility applications were 
available that did the job for you, however.

BTW: UNIX predates the Macintosh, but it was originally designed as an 
operating system for timeshared and networked computing devices. Time and 
date management is a critical part of such a design. Yet the Y2K bug 
(ambiguous date handling at the operating system level) managed to slip 
through and affects a huge number of UNIX system and application 
programs. Macintosh operating systems don't have a Y2K bug problem as 
accurate date management was considered a priority from the very 
beginning. Application developers still managed to do some silly things, 
regardless.

>If there is something that could compare to an M6, it is a Unix machine
>which stays up for months or even years on end, and which performs its
>tasks without fuss.

A Leica M6 has no automation systems at all, so your analogy of an M6 
with a UNIX system is somewhat less than valid. A computer is a device 
many orders of magnitude more complex than a Leica rangefinder camera. A 
Leica M is much more akin to a wind up kitchen timer than to any 
computer. Both Leica M and UNIX operating systems require maintenance. 
The UNIX operating system requires it on an ongoing basis, continuously 
while it is operating and at periodic intervals when it malfunctions. The 
Leica M's actual operating time is a very brief percentage of real time 
so its maintenance needs are spaced much further apart, but compared with 
actual time in operation it probably needs far more maintenance than a 
UNIX operating system.

When an M6 is not in use, its state is static. When put into use, you the 
user must make all settings relevant to your use of the M6: wind the 
shutter, set the shutter speed and lens opening, set the focus. A Leica M 
is never "up" in the sense of a computer OS: its "up" time (time in 
operation) is measured as the barest fractions of seconds against the 
continuous operation of an operating system. 

When a UNIX system is not in use (the machine is off), its state is 
static too, but when it powers up it must read the time from some 
originating source in order to reset itself properly, configure all the 
devices for use, etc. A UNIX system which is powered up is never idle the 
way an M6 is idle: the UNIX system is constantly doing something, running 
its devices and responding to changes in the clock, regardless of your 
interaction with it. You the user do not need to think about most of the 
configuration settings made and maintained by the OS and applications 
since automated processes have been implemented to do the job for you. 
The same is true of Windows and Mac OS. 

Godfrey