Audio
Computers
Super Simple JFET Preamp
Last Update: 20080706

Three stages, that are easily customized to a specific input and output by swapping resistors. It's as simple a design as I could make, using a minimum of components. With over a year of use in my audio chain, I find it helps fix phasing issues with common sources such as a CD/DVD player.

I have PCB's available for purchase for both the preamp (two channels per board), and a suitable power supply. With any purchase, I'm happy to include a suggested components list that is customized to your audio chain. The package (one preamp, and one power supply) costs $10: shipping included most anywhere.

Please send me any and all feedback. I would like to continue to develop this preamp to suit many systems. I think it has the ability to be a premium preamp, but I'm not an audio expert so I'm depending on you to help me improve it.

CentOS 4 Kernel with 100 HZ clock for VMWare
Last Update: 20080716

The problem is a clock that runs too fast or too slow. The solution is dependent on your host bios and guest kernel. My hosts are either i686 single core, with one or two processors, or x86_64 with single dual-core processors. I've found this solution to be independant of processor type.

All bios types

On the host, upgrade to the latest VMWare Server release, and make sure tools.syncTime = "TRUE" is in all of your .vmx configurations.

Power saving "Quiet 'n Cool," for example bios

Also add the following command for each core (processor) to /etc/init.d/vmware just after the line "echo 'Starting VMware services:'": /usr/bin/cpufreq-set -c 0 -d 2400000 -u 2400000 -g performance. (yum install cpufreq-utils) This will keep your processor running at maximum speed.

All guests

Use a kernel that has HZ of 100. I saw typical cpu usage per VM drop from 8-12% to 1-2%. Loadavg dropped by about 50%. The below are CentOS kernels (password required). But it's not hard to roll your own using the patch below.

You also need to add the following configuration flags to your guest's bootloader: clock=pit nosmp noapic nolapic

CentOS 4 Kernels
Boot Loader's
Last Update: Unknown

Ever bust your boot process? These may help. Just burn them to CD, and after boot, you'll get a chance to repair grub.

Bootable GRUB ISO's for system repair
Delete Windows Files
Last Update: Unknown

This is a simple minded, like the programmer, utility to delete files in mass based on timestamp: either creation or modification. I give myself a "C-" on this project. Works fine, but not very intuitive.

Windows File Deletion Utility