🚀 go-pugleaf

[close@cacilj.UUCP (Diane Barlow Close) writes...]

> There are actually 3 clocks in the ST.  They are the keyboard clock, the
> TOS clock, and the BIOS clock.

  Almost (but not quite) right.  There's a Gemdos clock but no "TOS
clock" and no seperate "Bios clock"...

  There are really only 2(!) clocks on the ST.  The Gemdos clock and the
keyboard clock.  The "bios clock" is really just two routines in the bios
for reading/setting the keyboard clock.  (The Gemdos clock determines
what time and date get stamped on files.)


> Some hard drives set only one clock.  My BMS card sets only the TOS clock.

(The following applies to cartridge and under-the-rom style clocks too.)

  It's not normaly the hard drives themselves that "set" the ST clocks,
it's usualy the hard disk boot code (rare) or a read-the-time program in
the auto folder.  What this means is that the hard drive companys can
(and I hope "will") fix this problem with their systems by releasing a
new readtime program or boot-code module.


> If I remember correctly, I think WP uses the BIOS 
> clock (a leftover from PC days, perhaps?).  Since the BMS clock
> only sets the TOS clock, my time and date in WP are screwed up
> (Jan 20 20??, way in the future).

  Correct...  That's the year (I think it's 2054) that the keyboard clock
shows if it has never been set correctly since power on.  (Note, power
on, not reboot.  If you set the keyboard clock once, it survives reboot
very nicely.  Some auto folder programs use this to only prompt you for
the time and date once after power on and you don't have to enter it
after a reset.)


** Programmer information warning ... :^)

  The keyboard clock will freeze under some situations when setting it.
I haven't been able to figure out exactly what causes it, but I do know
that the order of reading and then setting the two clocks does effect it.
Not enough time between reading and then setting the keyboard clock is
the most likely cause.

  As far as I can tell, this only occurs when you read the keyboard clock
and then set it.  If you only do one or the other, don't worry about it...

  I'm only mentioning this to let those who write programs that set the
keyboard clock know that they should, when writing their programs, test
the results very carefully and rearrange the function calls (to seperate
the read keyboard clock and set keyboard clock system calls as far as
possible), if necessary, to remove the problem.

** End of programmer information


	... John STanley

---
John Stanley <dynasoft!john@stag.UUCP>
Software Consultant / Dynasoft Systems