affect of HZ on XENIX

Mwa ha ha ericg at sco.COM
Sat Apr 9 01:54:03 AEST 1988


det at hawkmoon.MN.ORG (Derek E. Terveer) wrote in article <132 at hawkmoon.MN.ORG>:
>include one about the line frequency: "HZ=50".  Now, we are in the US so we
>should be at 60Hz, right?  Why is this set to 50?  Does it affect the system

The interrupt timer frequency and the frequency of common alternating
current in the US have as much in common as a liverwurst sandwich and
a girraffe.. i.e. none.

The HZ=50 is the rate in which the interrupt controller chip is 
sending interrupts.

>much?  Would the system be faster if its reset to 60?  Should i ignore this
>message?
>

If you set it to 60, strange things would occur, most notably your software
clock will run fast.

>I looked through all the include files i could find and these slices are all
>the references i could find to "HZ":
>
>	 */
>	#ifdef M_I86
>	#define	HZ	20		/* Ticks/second of the clock */
>	#define	SSIZE	1024		/* initial stack size (bytes) */
>	#endif

In other words, XT machines have interrupt timers that run at 20 Hz

>	
>	#ifdef M_I286
>	#define	HZ	50		/* Ticks/second of the clock */
>	#define	SSIZE	4096		/* initial stack size (bytes) */
>	#endif
>	

But AT machine's interrupt timers run at 50 Hz

>Derek Terveer	det at hawkmoon.MN.ORG	uunet!rosevax!elric!hawkmoon!det


-- 
I do not speak for SCO, I barely have enough room for my own opinions.
"When there is no more room in the river, the trout shall walk the earth."
                             
Eric Griswold |<help! i'm caught in the middle of a .signature>| ericg at sco.com



More information about the Comp.unix.xenix mailing list