[Oberon] File time stamps in PO2013

Charles Perkins chuck at kuracali.com
Thu Feb 13 20:36:13 CET 2020

I'm writing a linux kernel filesystem driver for Project Oberon disk images
and I'm wondering how best to interpret the Date field in the FileDesc

It looks to me like the Files module just puts the latest Kernel.Clock()
value in there when the file is written.

System.Mod sets the date value like this:
dt := ((((yr*16 + mo)*32 + day)*32 + hr)*64 + min)*64 + sec;

It looks to me like the above formula leaves 6 bits for the year, which
means it ranges from 0 to 63.

Now I know that the FPGA doesn't actually have a real time clock and I
think the time is always actually zero unless you set it to something else.
I don't think it gets updated from the system millisecond timer either.

I'm just wondering if historically that year value that goes in a file
header has a base year  or other meaning. Without something like that the
maximum year is "63" which is a long time ago!

I'd like to put something meaningful in this field when I move files in and
out of Linux.

Anybody have a good idea? Should I just make it based on Jan 1 1970 like
Unix, in which case it rolls over in 2033?

Am I over-thinking this?


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