This is the speed upgrade driver for HP100LX/200LX. It has been written for the 32.000MHz crystal of the FMODEM group. My set-up (HP200LX ROM Ver 1.02A 2MB JKIT) has problems with the timing using the standard upgrade drivers when connecting to the connectivity pack, in that it hangs when trying to receive, but we have also received reports that others do not have this specific problem. So the cause of this problem is not wholly clear. 

When the original FMODEM double-speed driver crystal is used, there is hardly any problem, but the screen clock is speeded up so that there are often stripes in the display under fluorescent light, making the display harder to read.

Usage: There are 2 types of driver: clkup31.sys and clkup32.sys. Clkup31.sys is for the FMODEM crystal - the exact double speed version. Clkup32.sys is the driver for the 32.000MHz version.
As the 32Mhz crystal is almost 1% fast, the driver is specially written to correct the speed-up of the system clock and serial port.
However, the frequency of beep and tempo of the music software and the playback rate etc. of PCM sound will remain 1% too high.

The program Dotclk.com allows tuning of the screen clock. With this program you can tune the speed of the screen clock, to give the cpu more processing cycles for programs. If you raise the value, screen flicker increases, but the system computes faster. Lowering the value especially improves presentation of the 4 possible gray-shades. You can also tune the value in such a way that is is in sync with fluorescent light, and you see no darker and lighter bands or flicker on the screen.

Initial value is 68. ( This value is chosen such that screenflicker in 4-shade cgamode is low, since it matches best with 60Hz fluorescent light.)
Usage:	> dotclk n

This program is Freeware. You can redistribute it for free, but may not sell it.


PXW03430@niftyserve.or.jp

HARUYA


