[Coco] Battery-Backed RTCs for CoCo?

Robert Gault robert.gault at att.net
Fri Nov 30 10:34:25 EST 2018


Jim,

Can't say much about relative cost of the RTCs but there is no reason to worry about IRQ problems. 
There is no need to update the OS-9 time frequently. Just always use the clock_soft module and run a 
separate program to read the RTC say every 10 minutes.

I have my NitrOS-9 set this way and even though a 9 byte initialize code must be sent to my RTC for 
each read, no significant time is lost.

Robert

RETRO Innovations wrote:
> So, what was the consensus for a replacement RTC?
>
> Re-reading the thread:
>
>   * DS1216 and DS1315 are compatible, but really expensive.
>   * They also use the "Phantom Clock" protocol, which Gene says can't be
>     used with code that uses IRQs.
>   * Most newer RTCs are I2C or SPI, both < $1.00, but they are not
>     compatible.
>
> Is compatibility more important than cost, or did something else get decided?
>
> Jim
>
>


More information about the Coco mailing list