(Comp.sys.hp48)
Item: 894 by prestonb@hpcvra.cv.hp.com [Preston Brown]
Date: 01 Jun 1993

[Note: somebody asked if the HP48 could be sped up by hardware
 modification.  Here's Preston's response.  -jkh-]

In the SX and GX the CPU clock is generated from a Phase locked loop
referenced to the 32KHz clock used by the timer.  Changing this
crystal would mess up the clock as well as the serial ports.

The CPU used in the GX is a new version with a pin to adjust the CPU
timing while leaving everything else at the old speed.  The memory
controller portion of the IC runs at the old speed; so this is like a
"DX2" (a clock doubled CPU running at the old bus speed).

Preston