Re: [cc65] two little bugs

From: Groepaz <>
Date: 2009-08-21 01:13:17
On Donnerstag 20 August 2009, Ullrich von Bassewitz wrote:

> I've a somewhat strange problem however: It seems that the CIA1 TOD clock
> needs a write to the 10th of seconds register to start running. This is
> independent of my program: If I use the IO command to check the registers,
> they're stuck until my program runs - and they won't change when my program
> is done. Is this a problem with my VICE version (I have 1.19 wich is really
> old)?
> I know that when writing the time, the clock gets stopped until the 10th of
> seconds register is written, so not completing such a sequence will stop
> the clock. But I cannot imagine that the C64 kernal does something like
> this?

when reading the time, the current status of hour/min/sec/10th sec will get 
latched when you read the hour, and the registers will no more change until 
you read the 10th sec register. so simply read hour first, 10th sec last :)
(writing to the registers does not affect this behaviour btw)


Hard work has a future payoff. Laziness pays off now.

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Received on Fri Aug 21 01:12:42 2009

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