How to Install Guest Additions in a Ubuntu VirtualBox VM

This article will show step by step how to How to Install Guest Additions to Ubuntu in a VirtualBox VM

Go to Devices menu then select Insert Guest Additions Cd image.

The pop up will show as picture below “”VBox_Gas_6.1.32” contains software intended to be automatically started. Would you like to run it?” then you have to click run

Fill the password then click Authenticate

After that wait until command line install until finish

If show the message as below, that mean you already finished install the Guest Additions to Ubuntu in a VirtualBox VM

Incase in case after you follow the steps and it does not show the pop up “”VBox_Gas_6.1.32” contains software intended to be automatically started. Would you like to run it?” you have to click to CD drive, it content files, and it has as below

Right click the file check Properties. Copy the path , example my path is /media/beer/VBox_GAs_6.1.32

Open terminal then paste command line cd to the path,
$cd /media/beer/VBox_GAs_6.1.32

Then run
$ sudo ./

If show the message as below, that mean you already finished install the Guest Additions to Ubuntu in a VirtualBox VM.

How to Search wording that content space on pdf file

Did you know we can search some text that content with space, example space on the separate table as example picture below

as you can see the numbers or ID that we want to searching is separate on the table, so we can search by add space, example search “1 0 0 3 0 255” on the pdf we can found the id that exactly match. you can try it. on this example I use pdf reader, Foxit reader, it also work with other pdf reader as well.

How to Export Chrome Bookmark to each Website file

This article will explain How to Export each bookmark from Chrome to file, each website each file, so you can organize easier as a file system.

We will need to Export the bookmark that we have in Google Chrome then export to 1 file, html 1 file then we will import to Internet Explorer (IE) then generate/ convert bookmark to each website file. Let check step by step follow this article below.

First Export Google Chrome Bookmark, On the right-hand side, select Bookmark manager

On the right-hand side click Export bookmarks

We will get one file .html Google Chrome Bookmark

Open Internet Explorer (IE)

On the right-hand side, Click on Star symbol select Add to favorites then Import and export…

Click Import from a file then click Next

Add Favorites click Next

Browse the Bookmark html file that we already Export from Google Chrome then click Next

Click Favorites then Click Next and Click Finish

Now the Internet Explorer (IE) will convert our bookmark file to each website file so we can get each file in this path C:\Users\xxx\Favorites when xxx is your Username

How to setting Mouse pointer

Many times, we do presentation or have an teleconference by online meeting platform such as Google Meet, Zoom or other application. We have to point something on the screen, and the cursor is very very small, difficult to see. It better to make Mouse become pointer like this,

How to do it let follow these steps below.

1.type mouse at start bar, select Mouse settings Additional mouse options

3.Mouse properties, you can should to change mouse cursor to become large by select scheme, Windows Black (Large), under Pointers section

4.then select checkbox Show location of pointer when I press the CTRL key, under Pointer Options.

Now when you press the CTRL key, the cursor will show circle blink all around at the cursor.

What is THD and How to calculate THD

THD or Total Harmonic Distortion (THD) is a value that indicates how the system has how much harmonic. When THD = 100% or 1.0 mean the system has 100% harmonic and THD = 0 mean No harmonic in the system.

In sound application, less THD means equipment has accurate, less noise and sound quality is very good.

In Power application, less THD means the system has a minimum loss, low heat loss. This is good for the system.

We can define THD of Voltage and Current by the formula. THD has 2 types of standard.

1) THD definition from IEC standard
Total harmonic distortion, THD (abbreviation) :
The ratio of the Root mean square (RMS) value of the harmonic content of an alternating quantity to the RMS value of the fundamental component of the quantity


Vh is Voltage RMS Harmonic order, Order 2 to Order n

V1 is Voltage RMS fundamental or V order 1 (no Harmonics)

h is an order of Harmonics Order 2 to Order n (h≥2)


Ih is Current RMS Harmonic order, Order 2 to Order n

I1 is Current RMS fundamental or I order 1 (no Harmonics)

h is an order of Harmonics Order 2 to Order n (h≥2)

The THD formula above, which is defined from IEC standard, it has the opportunity for value of THD more than 100% (Harmonicas value are combined more than fundamental order).

2) THD calculation


V is Voltage RMS include Harmonics and Fundamental order

I is Current RMS include Harmonics and Fundamental order

The THD formula, it has no opportunity for value of THD more than 100%. Because the num (include harmonics) has more value than den value.

From THD definition THD is ratio but most people are using THD value as percent and use formula follow IEC standard.

Example of THD calculation (IEC standard)

If Power system has Current Harmonic

Fundamental current = 100 A

5th Harmonic component  =  20 A

7th Harmonic component = 12 A

Current THD  = 0.23 or 23%.

What exactly is an ASIC

ASIC or Application-specific integrated circuit is Chip used for specific application things and they cannot use for general purposes like microcontroller or microprocessor. For Design ASIC, at first use design logic gate for application on FPGA (Field Programmable Gate Array) After that then make ASIC chip. Designers of digital ASICs often use coding to describe the functionality of ASIC for hardware description languages (HDL), such as Verilog or VHDL.

Advantage of ASIC

Power consumption and efficiency are very good because of the design for a specific application.

Price of ASIC chip when productions are the same as MCU.

Disadvantage of ASIC

Feature not flexible.

Difficult to develop and cost too high.

Time to Market is very poor because difficult to develop and need to test confirm before releasing to ASIC chip.

As you can see, the ASIC has advanced on efficient performance but in the disadvantage are take time to develop and not flexible.


Example ASIC chip

SHA256 ASIC for Bitcoin mining

Google Cloud TPU (Tensor Processing unit) for Machine learning application

Tesla Full Self-Driving chip (FSD) for automatic Self-Driving Car

How to Enable SMB1

If you found this error message like this,

You can’t connect to the file share because it’s not secure. This share requires the obsolete SMB1 protocol, which is unsafe and could expose your system to attack. You system require SMB2 or higher.  For more info on resolving this issues see:


That means your server file share is requiring SMB1 protocol. But to enable SMB1 is unsafe.  it need to update windows to latest version and then you  can enable SMB1 by follow this, Go to control panel programs and then click “Turn windows features on or off”. Scrolling to SMB1.0/CIFS File Sharing Support, check box SMB1.0/CIFS Client and Server as picture below,


How to use PuTTY for Serial port terminal

This article show how to use PuTTY as a Serial port terminal step by step.

First step at Session category you have to select Connection type to “Serial” and then specify Comport number and speed.

After that at Terminal category Select Local echo Force on and Local line editing Force on

Then Click at Serial is sub category in Connection category, configure detail of Serial port that you use such as Speed, data bits stop bit, Parity and Flow control

Click Open then you ready to use PuTTY as serial port terminal

How to fix SMBus Host Controller not enable in Vmware?

If you install Ubuntu and you found this error massage like this “SMBus Host Controller not enable!” and you want to fix it here is solution,

Edit blacklists.conf by $ sudo nano /etc/modprobe.d/blacklist.conf

And add “blacklist i2c-piix4” on the last line in blacklist.conf

After that reboot your virtual machine by $reboot

Finish, the massage “SMBus Host Controller not enable!” had already fixed.