Uninstall OS X extensions, additional audio devices (drivers)

A lot of third-party audio/video app (Screen recording apps) will install the additional audio device in the system preference panel.

To list all third party kernel extensions in Mac OS X:

In terminal:

kextstat | grep -v com.apple

To uninstall the extension:

sudo kextunload -b NAME_OF_THE_EXTENSION
e.g. sudo kextunload -b com.globaldelight.driver.Boom2Device

Continue reading Uninstall OS X extensions, additional audio devices (drivers)

Youtube Live Streaming Mac screen & system audio with OBS

My Settings:


2015 Macbook pro 13 with 2.7Ghz Intel Core i5 & 8Gb Ram

OS X El Capitan 10.11.6 + OBS 0.15.1 (Mac Version)

Internet: 100Mbps download; 7Mbps upload

First, schedule a Youtube Live Event:

Youtube-> Creator Studio-> Live Streaming -> Events -> New Live Event: Continue reading Youtube Live Streaming Mac screen & system audio with OBS

OS X fonts look different on external Monitor

When the Macbook Pro connects to an external LCD monitor, fonts look very strange in some program  (Like Terminal) on the external monitor. It happened on 2015 Macbook Pro w/ OS X El Capitan 10.11.6.  Monitor AOC E2429SWHE.

It appears the fonts on an external monitor are not smoothing because system mistakenly recognizes the monitor as CRT.

To solve: In Terminal

defaults -currentHost write -globalDomain AppleFontSmoothing -int 2

The number 2 here corresponds to Medium – Best for Flat Panel. You may also use 1 for light smoothing, and 3 for strong smoothing, as per the original OS X font smoothing options.

Relaunch the program to take effect.




for hour in range(0, 11, 1):
       for minute in range(0, 59, 1):
              m_angle = minute * 360/60
              h_angle = hour * 360/12 + 360/12/60 * minute    # in this case, '/' is integer divider
              if m_angle == h_angle:  # integer approx. comparing
              print hour, round(30/5.5 * hour, 1) # 30hour + 0.5minute = 6minute, solve minute=30/5.5hour

2. 上述代码里算角度的除法实际上得到的是integer,因此if判断语句得到的(hour,miute)结果并不是真正重合的时间,只是过了这个时间后很快就有一次重合

3. 通过代码也理清了思路,实际上每小时都会有一次重合,至于是什么时间重合,实际上是解下面这个方程:

Continue reading 12小时内时针分针重合几次?

Speed Up Window Resizing Animation Speed in Mac OS X 10.10 El Capitan

OS X 10.10 Full screen resizing animation is annoying.

No way to turn the animation off, only to speed up.

In terminal:

defaults write -g NSWindowResizeTime -float 0.001

To turn off:

defaults delete -g NSWindowResizeTime


Extract Windows 10 beautiful spotlight (lock screen) wallpaper

  1. Enable ‘Show hidden files’
  2. Go to This PC > C: > Users > [Your User Name] > AppData > Local > Packages > Microsoft.Windows.ContentDeliveryManager_cw5n1h2txyewy > LocalState > Assets
  3. Copy out all the files to a new Folder e.g. ‘Foo’
  4. Within foler ‘Foo’, enter into Windows Command line prompt (CMD), bulk rename all files with .jpg extension using this command:  >  ren * *.jpg
  5. View all the jpg files, select the one you want. Done.

OS X 10.10 Yosemite Transfer Old Apps Settings to New Hard drive

Copy files from old hard drive to new. If user name changed, need to change owner for old files.

1. Show hidden files in the Finder
In terminal:
defaults write com.apple.finder AppleShowAllFiles Yes
killall Finder

2. Message App:
1) Open Messages on both Macs and go Preferences > Accounts > iMessage > Sign Out
2) Copy these folders and override from old Mac to new Mac


3) Restart new Mac
4) Open Messages and sign in to iMessages again

3. Dictionary App

4. Mail App