Reading from the CMOS clock

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2 total messages Started by Nick Smith Tue, 01 Sep 1992 10:41

#205

Author: Nick Smith
Date: Tue, 01 Sep 1992 10:41

18 lines
1362 bytes

I'm having a little trouble with some code I'm writing at the moment:

For various essential reasons, I have to turn off interrupts for upto
several minutes at a time. What I *want* to do, is preserve the real time
clock (I know how long I will have interrupts disabled exactly)

I know that the soft copy of the realtime clock will halt during this period,
but I felt sure that the CMOS (hardware) clock, which after all works when
the machine is switched off, would continue happily with no interrupts ...

I am using OS_Word,14,1 which claims to read the real time from CMOS clock in
BCD (ug) format. Thing is, it contains the same value before & after the
code with no ints. has been called.

So what am I doing wrong ???!
--
Nick Smith, Churchill College, Cambridge, UK.  %$%  Email: nas20@uk.ac.cam.phx
sig quote wanted - must be under guarantee.   $%$  --- Usual disclaimer. ---

Re: Reading from the CMOS clock

#206

Author: Nick Smith
Date: Tue, 01 Sep 1992 16:45

18 lines
1518 bytes

In article <1992Sep1.104148.12279@infodev.cam.ac.uk> nas20@cl.cam.ac.uk (Nick Smith) writes:
>I'm having a little trouble with some code I'm writing at the moment:
>
>For various essential reasons, I have to turn off interrupts for upto
>several minutes at a time. What I *want* to do, is preserve the real time
>clock (I know how long I will have interrupts disabled exactly)
>
Oh yeah, I have tried adding the time delay to the old clock value, then 
writing it, but the time-based SWIs are rather limiting - you can only read
the CMOS clock as BCD (precision 1 sec), and you can only write the CMOS
clock as a string, and while there is a SWI to convet BCD->string a) it has
insufficient precision, and b) it requires that you know how many days are there in each month, and worry about leap years, etc, etc - too much hassle !



--
Nick Smith, Churchill College, Cambridge, UK.  %$%  Email: nas20@uk.ac.cam.phx
sig quote wanted - must be under guarantee.   $%$  --- Usual disclaimer. ---

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