[Coco] Battery-Backed RTCs for CoCo?

Robert Gault robert.gault at att.net
Fri Nov 30 19:26:01 EST 2018


That must be the clock2_coco3fpga.asm as that is "for the Maxim Integrated DS3231 RTC."

Again that code gets read more often than is necessary. You could use the clock_soft, convert 
clock2_coco3fpga.asm to a stand alone program, and read the RTC every ten or more minutes. As long 
as the RTC is automatically read on a Boot, the system clock will be more than accurate enough for 
any disk file label or other time stamp required.

Dave Philipsen wrote:
> Actually we have a NitrOS9 driver for the newer (and cheaper) DS3231 chip that is so prevalent on
> many RTC boards available on eBay.  It is currently used on the CoCo3FPGA.  I believe that the
> general register architecture of the Dallas Semi chips are all pretty much the same. It's just that
> the older ones were accessed in a slightly different way before the advent of I2C and SPI.
>
> Dave
>


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