Dual Systems - CLK24C Clock Board
There were a few different versions/revisions of this
board. The picture below is the first Rev A version. Later versions used a
circular battery holder.
The heart of the CLK-24 was the OKI MSM5832, which can be read by the
computer to give the current time or date. The CMOS integrated circuit uses
so little power that with one small battery it could keep time for over
three years with the computer power off.
The CLK-24C was easy to use. The time and date may be set or read from
either BASIC, assembly language, or any other language that allows access to
the I/O ports. Programming examples were included in the manual.
For critical timing applications or operating system requirements the CLK-2M
could generate vectored interrupts on intervals of minutes, seconds, 1/64
second and 1/1024 second. This was useful if, for example, you wish to
display the current time every second or minute, concurrent with normal
The board was very similar to the the
CompuTime clock board
the same chip.
It looks like there are at least two versions of this
board. I actually have an earlier version, shown below. As far as I
can tell both boards are the same from a software point of view.
The manual for this board may be
Other Dual Systems
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