Subject: Re: Stability Date: 10 Sep 1996 17:27:53 GMT From: Dave Arnett Organization: Hewlett-Packard, MCD Newsgroups: comp.sys.hp48 The timing source for the HP48 (G/GX and S/SX) is a quartz crystal tuned to 32768 Hz. The Yorke IC basically contains a phase- locked loop which multiplies this frequency up to the operating frequency. I am told that this design has some noise intentionally inserted into the PLL to slightly destabilise it. (This is a well known technique for reducing interference with radio trasmissions by increasing the spectral bandwidth of the clock.) Dave. ------ I don't speak for HP when I post here.