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Archive for the ‘Computer and Internet’ Category

Windows 10 Insider Preview on VirtualBox

Posted by binglongx on June 29, 2015

I downloaded Windows 10 Preview through Windows Insider Program. With Oracle VirtualBox at my disposal, I can install Windows 10 Preview as a guest OS in the virtual machine and have a quick impression on Windows 10 without risking my current working system.

Install Windows 10 in VirtualBox

This is what I did to setup a virtual machine.

  • Download Windows 10 Preview ISO file. I use the 64-bit version Windows10_InsiderPreview_x64_EN-US_10130.iso.
  • Make sure you installed latest VirtualBox. I have VirtualBox 4.2.16 (x64) on my Windows 8.1 x64.
  • In VirtualBox, click New button (or Machine | New… menu item). This brings the Create Virtual Machine dialog box.
  • I choose the machine Name Windows10Preview, Type Microsoft Windows, and Version Windows 8.1 (64-bit). My VirtualBox does not directly support Windows 10 yet, so pretend to be Windows 8.1 for now. I tried Other Windows and the virtual machine would not boot.


  • Go through other regular settings, including Enable 3D Acceleration and Enable 2D Video Acceleration, and create the virtual machine. Then select the virtual machine, choose Settings | Storage, for Controller: IDE, mount the downloaded ISO as the CD drive. This is to let installer in the ISO run and install Windows 10 to the virtual machine when it boots.


  • Now start the virtual machine in VirtualBox. Go through the Windows installation routine. Eventually, you arrive at Windows 10:


That’s quite smooth.

You can unmount the ISO file from the IDE CD drive of the virtual machine now.

Change Screen Resolution for Windows 10 Virtual Machine

Due to the fact that Windows 10 is not natively supported by my VirtualBox, there is an immediate annoyance. The guest Windows 10 box has very limited choices for its screen resolution. My physical display is 1920×1080, but the Windows 10’s Microsoft Basic Display Adaptor only support video modes like, 640×480, 800×600, 1024×768, 1152×864, 1280×1024, and 1600×1200. None of them is suitable for my display.

Following the guide here, this is how I changed the screen resolution to match my display.

  • Shut down Windows 10 virtual machine if it was not.
  • Make sure that virtual machine is selected in VirtualBox, but not started:


  • In the host Windows system, run cmd.exe to open up a command line console window. Change directory to the VirtualBox installation directory (C:\Program Files\Oracle\VirtualBox on my Windows 8.1 x64), then run command VBoxManage.exe setextradata to add a custom video mode to the guest virtual machine you created. You can use VBoxManage.exe getextradata to verify the virtual machine has the data you set. This is what I run for my virtual machine “Windows10Preview”:
cd "C:\Program Files\Oracle\VirtualBox"
VBoxManage.exe setextradata "Windows10Preview" CustomVideoMode1 1920x1080x32
VBoxManage.exe getextradata "Windows10Preview" CustomVideoMode1
VBoxManage.exe getextradata "Windows10Preview" enumerate
  • This is a screenshot of my command line window:


  • Now start the virtual machine in VirtualBox. Go to Display Settings, you will find that the new resolution is available:


  • If you dig deeper, you can list all modes in the Microsoft Basic Display Adapter, and find the new resolution there:


  • Use that resolution, and the screen looks much better:



It’s quite easy to install Windows 10 Preview in VirtualBox, and following a few steps the virtual Windows 10 can use the full physical display resolution. I think a later version of VirtualBox will make this much easier.

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Aukey Turbo Charger PA-U28 Impression

Posted by binglongx on June 7, 2015

As mentioned in an earlier post, Aukey Turbo Charger PA-U28 is a USB charger that supports Qualcomm Quick Charge 2.0 (QC2.0). This means it can charge QC2.0 compatible devices much faster, such as Moto X 2nd generation (Moto X2) phone.

The original wall charger coming with Moto X2 (rated 5.0V/1150mA) charges Moto X2 rather slowly. This is one measured example:

Charging Time (minutes) Battery Level
+  0 4%
+ 20 23%
+ 30 32%
+ 87 83%
+128 99%

On contrast, the Aukey Turbo Charger charges much faster. This is one measured example:

Charging Time (minutes) Battery Level
+  0 5%
+ 20 42%
+ 45 72%

In both examples, the Moto X2 phone was idle with Wi-Fi on while charging.

Aukey QC charger charges the phone much faster. When the battery level is low, it charges almost twice as fast as the factory non-QC charger (20 minutes to up the battery level by 37% vs. 19%). The phone was also hot when charged with Aukey charger; while it was not even warm when charged with the Moto X2 charger. When the battery level is higher, Aukey QC charger starts to slow down.

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USB Chargers

Posted by binglongx on May 13, 2015

A Myriad of USB Chargers

With the popularity of microUSB based charging on latest smart phones, tablets, and even some 2-in-1 laptops/tablets, I have basically quite some chargers around in home. These chargers normally have a USB A female socket and use a USB to microUSB cable, to charge the devices that has a microUSB female port. I just simply call them USB chargers.

Most of these USB chargers can be characterized with the rated output voltage and current. Below are some that I have:


Charger Voltage (V)

Charger Current (A)

LG Optimus V 5.1 0.70
Motorola DEFY XT 5.1 0.85
Samsung Galaxy Rush 5.0 1.00
Moto X 2nd Generation 5.0 1.15
Hisense SERO 7 Pro 5.0 2.00
Asus Transformer Book T100 5.0 2.00
HP Touchpad 5.3 2.00

As you can see, they have similar output voltages. Most of them have 5.0V rating. HP Touchpad has the highest output voltage, 5.3V. Their output currents can vary a lot though.

All the manufacturers warn that only their approved chargers can be used to charge the devices, to avoid damaging the device or charger. Of course this should be followed if possible. But I think we all have the chances that we want to just charge it with any convenient charger that we can grab close by. Can we do that?

USB Charging Basics

The USB interface has 4 wires/pins, Vcc(i.e., Vbus, +5V), D-, D+, Ground. Although USB was mainly designed for data communication, the presence of Vcc and Ground allows supplying power from one device to another device. The USB standard only allows the A-type socket to provide power. That’s why all these charges have a USB-A socket.

Any A-type socket may be ready to provide power, so it is dangerous to connect two A-type sockets using a USB A to A cable. That’s why most USB cables have only one A-type end; the other end is either B-type or micro-B type.

The device that receives power from USB normally have either USB-B type or microUSB-B type connector. In fact, ITU and other standard bodies endorse micro-B USB as data exchange and charging interface for the phones (and tablets). There are exceptions, such as Apple products that use the proprietary Lightning port, but they also provide microUSB to Lightning adaptors.

Connectivity aside, the actual charging involves drawing power in a way such that both the charger and the device agree. Unfortunately, this is very messy in the USB world. You can check The Basics of USB Battery Charging: A Survival Guide for details, but this is a short summary.

  • The dumbest charger/device just provides/draws power without any negotiation. The charger just leaves D+/D- float (not connected). The device may use D+/D- for data communication, but when in charging it does not check or makes no use of the two wires. Basically, it just uses USB as two wires and that’s it. This is not compliant to any USB standard. I suspect most cheap USB chargers are still like this.
  • USB 1.0/2.0 Power Specs. The initial USB 1.0/2.0 specs define two power supplying modes: 5V 100mA (Low Power) and 5V 500mA (High Power). A device can draw 100mA once connected to a USB power source; then it establishes USB digital data communication with the source through D+/D-, and use a digital protocol to negotiate with the source. It may be allowed to draw 500mA, or instructed to keep in the Low Power mode.
  • USB BC 1.1. The USB 1.0/2.0 Power Specs do not provide enough power to more power hungry devices, so a new spec, BC 1.1 comes to help. In BC 1.1, the device needs to check D+/D- (and sometimes additionally perform digital negotiation) to draw power from the source. There are three types of USB power sources:
    • Dedicated Charging Port (DCP). DCP internally shorts D+ and D- with a resistor of 0-200 Ohm. The device can detect the short and discover the source is a DCP. No digital communication is necessary. A DCP can supply up to 1.5A. DCP is still relatively dumb, and a lot of wall plug or car chargers belong to this category. A DCP does not perform data communication, i.e., is purely a power source.
    • Charging Downstream Port (CDP). A device needs to negotiate with CDP using hardware handshake through manipulating and monitoring D+/D- levels, however, no digital communication negotiation is needed. CDP can supply up to 1.5A. CDP powering and USB data communication can co-exist. Newer PCs and laptops have USB ports as CDPs to charge other devices.
    • Standard Downstream Port (SDP). SDP is basically the USB 1.0/2.0 Power Specs port (100mA or 500mA). BC 1.1 requires both D+ and D- to be grounded with 15k-25k Ohm resistor, and the device can detect that. From there, USB 1.0/2.0 Power Spec negotiation through digital communication is performed to determine whether possible to get to High Power mode. SDP powering and USB data communication can co-exist. Older PCs and laptops have USB ports as SDPs to charge other devices.
  • Manufacturer specific protocols
    • Apple chargers. Apple chargers pull D+/D- to certain levels, and Apple devices detect the levels to determine how much current to pull from the charger. See iCharging: The mysteries of Apple device charging for details.
    • Qualcomm Quick Charge. Qualcomm Quick Charge is open USB charging technology, see below.

A lot of USB wall chargers are dumbest chargers. The have arbitrary amperage ratings and non-5V voltage ratings, therefore are not conformant to the USB standards.

In general, higher charger output voltage means more capable in charging devices. For example, if I try to charge HP Touchpad with SERO 7 charger, most likely it would not charge anything, because the output voltage is just too low out of the charger. One the other hand, my HP Touchpad charger is the most powerful one and charges all the devices in my home. I was even successful in reviving almost dead battery of LG Optimus and breaking its boot loop as described in a previous post.

The output current dictates how fast the charger charges the device. For example, with the same output voltage, a 2.0A charger can charge 2 times as fast as a 1.0A charger. Normally more powerful devices have batteries of higher capacities, and use chargers with higher current ratings, so they do not need long time to recharge.

Asus Transformer Book T100 and BatteryBar

A lot of devices are also dumbest devices per USB charging. It draws power from the charger as long as it deems safe, without complying to the USB standards.

For some devices that try to be conformant, they may appear as picky ones, because they only draw a safe amount of current if they cannot determine the source type when the source is the dumbest charger.

The Asus Transformer Book T100 is 2-in-1 laptop/tablet that is “notorious” for picking chargers. Basically, its accompanying charger is slow in recharging the tablet. People try to use some other chargers with higher currents (and similar voltages), but they often find that it is charged even slower, drawing merely 500mA. Some people come up with mods to short D+ and D- in a dumbest charger, therefore per BC 1.1 DCP, T100 can draw up to 1.5A. Some other people report that not only T100 may be picky on chargers, but also picky on USB cables.

I am not sure if it’s really the different charging protocol, or just the voltage loss is too much on long USB cables of inferior quality (thinner metal wires therefore bigger resistance). And I do not want to modify my chargers. Luckily there is an application called BatteryBar in Windows, which can report the charging rate in real-time. BatteryBar Pro is $8, but I find the free BatteryBar Basic version is good enough for my purpose. It is only for Windows though.

Once installed, BatteryBar displays a toolbar on Windows bar. If you click it, it shows more information. While charging, the most important information is the wattage. For Asus T100 and HP Touchpad charger, I do find that a 6-feet-long USB cable would yield only about 2500mW (i.e., 500mA at 5V) charging, but a 3-feet-long USB cable would give about 5000mW (1000mA) charging. That’s a difference between 12+ hours and 6 hours for a full recharge. Asus T100 and Aukey Turbo Charger (see below) work at about 5000mW as well.

Qualcomm Quick Charge

Qualcomm’s Quick Charge technology provides another way to charge the devices faster by boosting the line voltage.

Qualcomm Quick Charge uses the same conventional USB A to microUSB-B cable. However, if both the charger and device are Quick Charge compliant, they can negotiate about faster charging. Quick Charge 1.0 allows up to 10W (5V/2A) charging. Quick Charge 2.0 can use various voltages up to 12V, at 3A current, the charging speed is 36W.

Similar to Apple charging protocols, Qualcomm Quick Charge uses the D+/D- levels to negotiate the charging speed. Below is an illustration (image courtesy Qualcomm Quick Charge 2.0 protocol specification and support).

Quick Charge 2.0 Specification Diagram

Devices using latest Snapdragon SoCs support Quick Charge 2.0, including phones and tablets. Other devices may support Quick Charge as well. You can check here for certified devices.

You can also find Quick Charge certified chargers here. Quick Charge 2.0 certified chargers can output different voltages. If you check the fine text on the charger, you will not see one voltage like 5V, but instead you will see 5V, 9V and 12V with respective current ratings. The key to charge faster is that the charger outputs high voltage with high current, and the device’s charging circuit would convert it to low voltage with even higher current to charge the battery.

As long as both charger and device conform to Quick Charge, they can come from different vendors. This should make you worry less when exchanging charges for your Quick Charge enabled device.

Qualcomm Quick Charge is backward compatible with conventional USB charging.

  • If the charger is conventional, Quick Charge device behaves like a conventional device, and charging is slow.
  • If the charger is Quick Charge certified but the device is conventional, charging falls back to 5V and is slow. Your device will not be fried.
  • If both charger and device are Quick Charge enabled, they negotiate at a high power charging and charging is fast.
  • Quick Charge 2.0 is also backward compatible with Quick Charge 1.0.

AndroidAuthority has a nice article explaining Quick Charge. The FAQ of Qualcomm Quick Charge can be found here.

The devices keep being more powerful and requiring larger battery capacity, and technologies like Quick Charge will be more popular. In fact, both Moto X 2nd Generation and Asus Transformer Book T100 supports Quick Charge 2.0, per device list. I just bought a Quick Charge certified Aukey charger off Amazon for a little over $10. This charger is able to output 12V/1.5A, i.e., 18W, which is promising.


In one occasion, the Aukey Turbo Charger charged Moto X2 from 5% to 42% in 20 minutes (both the phone and charger got hot). In the next 25 minutes, it continued to charge to 72%. This seems to be pretty good. It however yields only about 5000mW on Asus T100 according to BatteryBar.

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Delete Wireless Network Profile in Windows 8

Posted by binglongx on May 13, 2015


If you cannot find “Forget this network” when you want to delete a Wi-Fi profile, just use the command line below:

netsh wlan delete profile name=”Your_SSID”

I use “Command Prompt (Admin)” from the Windows button to run the command above.


How to Manage Wireless Network Connections & Profiles in Windows 8

Windows 8 – Manage Wireless Networks?

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Dropbox Referral Program For 500MB Extra Free Bonus Space

Posted by binglongx on February 12, 2015

Dropbox is a cloud storage service. It is like a remote online drive that you can put your files there. It is slower than your local hard drive, but it is super reliable. A basic personal account is free to open, and it has 2GB free space.

I have been using Dropbox for quite a few years. There are many nice features of it. For me, the most convenient feature of Dropbox is automatic uploading of photos that I take on my mobile phone. I just install the Dropbox app on my Android phone, and set up the automatic uploading. Whenever I take a picture, it would be backed up to my online Dropbox account automatically. It saved a lot of photos when my microSD card in my phone went wrong some time ago.

If you open an account at Dropbox right now, you get 2GB free space. However, if you create a Dropbox account through a referral link from an existing Dropbox user, you will get extra 500MB space, i.e., 2.5GB total free space. The existing user will also get 500MB extra space for free.

If you so happen to need a Dropbox account, you can use my referral link To get the 500MB extra space, you need to:

  • Use the referral link to create a new Dropbox account; and
  • Install the Dropbox desktop application on a Windows, Linux or Mac computer; and
  • Sign in to the installed application with the newly created Dropbox account.

That’s it. You will see 2.5GB (instead of 2.0GB) space available in your Dropbox account. And thanks, this will also add 500MB to my Dropbox account. If you need more space, you can publish your referral link to earn bonus space.

Please note that, for this to work, you have to install the Dropbox desktop application on a desktop computer. Installing the Dropbox app on your Android or iOS phone or tablet does NOT qualify for the referral program.

For details, you can also check with Dropbox Referral Program.

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Microsoft Wheel Mouse Optical: Fix Button Click Problems

Posted by binglongx on October 4, 2014

I have two of Microsoft Wheel Mouse Optical. I have used them for maybe more than 10 years. They are not fancy, but they have been very reliable for so many years. However, recently both of them have behaved strangely. One did not respond when I clicked the left mouse button. The other one often double clicked while I only clicked the left button once. This is a picture of one of them:


They look a bit old and don’t worth much. In fact, repairing them may not worth the time either. However, they are electronic waste and I don’t bother to go somewhere just to recycle them. So I think I should repair them!

Searching over the internet, I found this nice article: Repair mouse with double click problem. It is about a different Logitech mouse, but it helps a lot for me to open the case. The Microsoft mouse is in fact harder to open because it has two screws and two plastic tabs under the sticky pads. The two plastic tabs needed to be pushed hard while I pried the side of the mouse.

This was how the interior looked like in the Microsoft mouse after I cleaned the dust:


I have highlighted the faulty switch on the circuit board corresponding to the left mouse button. To take out the smaller circuit board and reach the faulty button, I needed to remove the wheel first. Lifting the wheel axle from the plastic holding:



Removing the two screws on the bigger circuit board:


The smaller circuit board is held to the back case of mouse with three half-transparent plastic tabs, use small flat head screw driver to carefully pry them and lift the board:


It is easy to see that, unlike that of the Logitech mouse, the switch component in the Microsoft mouse is monolithic and probably impossible to repair if its internals go wrong or unreliable.

I looked around and noticed the third switch (in blue circle) other than the left (in red circle) and right button switches:


That’s the middle button switch. I use the middle wheel of the mouse often to scroll pages, but I have almost never used the middle button clicks. Obviously, the left button switch has been heavily used for 10+ years and has worn out, but the middle button switch has been virtually unused in so many years. I could swap the left button switch and middle button switch and it does not hurt anything to me!

I took out my soldering iron. Liana and Colin helped to hold the circuit boards (with a great deal of caution as the iron was really hot) and I removed the switches from the boards. They looked exactly the same so I was very careful to put the good middle button switch aside. This was one of the switches:


Then I swap the switches and soldered them back to the circuit board. Connect it to the computer, and verify the left button switch works:


I then closed the cover, tightened screws and re-attach the sticky pads. The switches from middle button should be strong enough to work for quite some years, maybe until Gesture UI replaces the mouse!

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Remove Malware “Fast and Safe”

Posted by binglongx on September 7, 2014

My wife tried to use her computer with her employer’s VPN. The VPN client did not work until she turned off Windows Firewall. I could have made the VPN client an exception in Windows Firewall earlier, but in 2 days when the firewall was off, her computer showed annoyances.

First of all, her Chrome browser started with an unfamiliar home page, not that she had used. When she visited LinkedIn, there were extra blocks of fishy ads right in the LinkedIn web page. Google search also showed extra funny ad blocks. As contrast, Chrome on my computer does not have this problem.

I checked her Chrome settings, and found two strange extensions. The Chrome on my computer has only one Google Docs extension. I deleted the two extra extensions from her Chrome. After restarting, her Chrome worked fine.

I though it was done. But the next day she said, those annoyances came back to her Chrome again! And she found her Internet Explorer (IE) had the same problem! I went into Manage add-ons in IE, and found fishy add-ons like deal2x, saveas etc. They resided under hidden C:/ProgramData folder. Even running IE as Administrator would not allow me to delete these add-ons. They were rogue add-ons. Very likely, there could be something that would run automatically messing up the system.

A very well known tool to check what run automatically in Windows is Autoruns. This is a green application, just extract the files to a local folder, and run autoruns.exe. It revealed the IE add-ons. I tried to delete them from within Autoruns but it complained it could not find the files, although they were there. More importantly, it showed that AppInit was hooked up by fastandsafe.dll. Hooking up AppInit can hijack Windows API calls, and anything doing that is automatically suspicious. A simple Google search showed that Fast and Safe is malware.

One simple way to remove those stubborn malware is to reboot into Safe Mode of Windows. In this mode Windows loads minimal device drivers and runs least autorun programs, therefore the bad code does not get to run, and we can clean it. It’s a bit involved to boot into Safe Mode for Windows 8 or 8.1. After booting in Safe Mode, I ran Autoruns again, then deleted the AppInit and Internet Explorer entries, then went to C:\ProgramData and deleted those fishy subdirectories. I also deleted the Chrome extensions.

After rebooting, her computer has been normal. Of course, I make sure Windows Defender and Windows Firewall are enabled.

Update 6/14/2015: A friend’s Windows 7 laptop went wild with unrecognized software popping up. With Autoruns, it was shown that there was a fishy entry in the drivers list: c:\windows\system32\drivers\usbadmi.sys. Be especially careful about the entries with empty or fishy Description/Publisher in Services and Drivers in Autoruns.

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Watch Amazon Instant Video on Android

Posted by binglongx on June 28, 2014

If you want to watch Amazon Instant Video on your Android phone or tablet, you may be surprised to find that there is no such app available on Google Play Store. You can of course try to use the web Browser app in Android, get to Amazon’s website, and log in to Instant Video; but when you click any title, it does not play, and you see this message: “You can watch it on Kindle Fire, mobile devices, game consoles and other compatible devices”. Amazon’s list of Compatible Mobile Devices includes only Amazon Kindle, its new Fire Phone, and Apple iPad/iPhone/iPod Touch series. As you already know, Android phone/tablet is not on the list. It is unacceptable that Amazon Instant Video subscribers cannot use Android phones or tablets to watch the titles.

Android users basically have only one workaround – pretending to be using a Desktop web browser, like watching on your Windows PC.

Install Dolphin Browser

We need a bowser app on Android that can pretend to be a Desktop web browser. Luckily, Dolphin is such a browser on Android that you can set User agent to “Desktop”. That way the web servers would believe you are using a desktop computer than a phone/tablet. You can install Dolphin from Play Store.

When Dolphin is running, touch the little dolphin icon to the right of the web URL box, then choose Settings icon (to the left of Dolphin icon in the pop up), choose Customize, then touch User agent and change to Desktop.

Use Adobe Flash Instead of Microsoft Silverlight

If you think that’s it, you are wrong. Now you run Dolphin, log in to your Amazon account, and get to Instant Video. When you click to watch a video, it does not play and says that it needs Microsoft Silverlight. Silverlight is a web browser plug-in for PC. Amazon does not know your browser is in fact running on Android. It thinks you are running on Windows. The problem is, there is no Silverlight on Android! Microsoft does not provide that support for Android.

Amazon used to use Adobe Flash for playing videos in web browser. Some old posts over the internet worked with that assumption. But Amazon became favoring Microsoft Silverlight from Adobe Flash.

However, Amazon still allows you to use Flash. You need to click Settings in the web page and get to Amazon Instant Video Settings. Scroll down to near the bottom, you find WEB PLAYER PREFERENCES, and you choose Adobe Flash Player instead of Silverlight (Recommended). Now that annoying Download Silverlight message is gone.

Install Adobe Flash Player

But, most likely your Dolphin still does not play the movie. On my HP Touchpad CM10 (Android 4.0.4), Dolphin shows a little cube with a few question marks – basically no Adobe Flash Player is available in my Android tablet. Abode stopped support of Flash Player on mobile platforms a few years back. Most Android systems do not come with Adobe Flash Player installed today.

However, you can still download the stagnant Flash Player 11.1 for Android from Flash Player archives at Adobe. For example, depending on your Android version, you can download:

After the apk is downloaded, just install it and you are done. Now you can come back to Dolphin and reload the page, your Amazon Instant Video now plays!

Update 7/16/2014: Amazon has confirmed that it will launch an Android app for its video streaming service “soon” (PC Advisor).

Posted in Android, Computer and Internet | Tagged: , , , , , , , | 2 Comments »

Flash Padavan Custom Firmware on Asus RT-N65R (RT-N65U)

Posted by binglongx on June 12, 2014

Introduction to Asus RT-N65R/RT-N65U

Asus RT-N65R is a powerful home wireless router. You can find both RT-N65R and RT-N65U models, but they are exactly the same hardware. RT-N65R is the retail version sold by Best Buy and so on, and RT-N65U is supposedly sold by Asus directly. The only difference is the firmware on board. In fact, if you go to Asus support website, you will find the firmware updates for RT-N65R and the firmware updates for RT-N65U are exactly the same. From now on, you can assume that they are the same model.

Why do you need to consider this router? There are a few reasons.

  • The router is very affordable. It is not 802.11ac so not the fastest. But that’s why you may get it for cheap. The AC models are almost all well above $100, but you may get this one for less than $50.
  • The router is feature-rich and powerful.
    • Dual-band 802.11n with theoretical 750Mbps speed
    • Pretty good range coverage for most homes
    • 2 USB ports for storage, printers and so on
    • Ralink RT3883 500MHz CPU, 128MB RAM, 16MB Flash
  • You can install custom firmware. Given its powerful CPU and ample RAM/Flash, with USB storage drive, it can easily be turned into an always-on Linux server. You may use it as file server, VOIP server, and so on. This is the most appealing reason that I bought this router.

The in-depth review can be found at There are some concerns with this router that you may want to know:

  • Even though the 2 USB ports are USB 3.0, do not insert USB 3.0 devices. The hardware has flaws. Inserting USB 3.0 devices would interfere with 2.4GHz band and causing devices on this band to disconnect from the router. It is however fine if you only use USB 2.0 devices on the 2 ports. For details, see here. If you have to use USB 3.0 devices, you need to look at other models.
  • The router runs warm/hot. Some users worry that heat may prematurely damage the router. Asus says it is designed to withstand that heat. Just remember to have enough clearance on all sides when positioning the router.

The factory AsusWrt web UI is pretty and powerful. It looks like this:

However, custom firmware offers more features and flexibility. DD-WRT and Tomato supports some Asus routers, but not RT-N65U. Recent Asus routers run the unified AsusWrt firmware, which is mostly open source (except certain modules from chip vendors). That makes the (benevolent) hackers easier to create custom firmware. Although stock AsusWrt is already quite flexible for hackers, custom firmware such as AsusWrt-Merlin is even more flexible. AsusWrt-Merlin however does not support RT-N65U yet.

Flash Padavan Custom Firmware and Install Entware

Luckily the Padavan custom firmware supports RT-N65U (and some other Asus routers such as RT-N56U/R, RT-N14U). From here, you can see the Padavan firmware has a lot of built-in features. If that is not enough, the Padavan firmware supports Entware. Entware is a package repository for embedded devices. If you have no clue, Entware for router is like App Store for smart phone. Running Entware package manager utility opkg, you can download and install many software packages on the router, and turn it into a versatile little server machine. For example, you can install Asterisk PBX, with whose SIP support the router can be a VOIP server.

Flashing custom firmware to AsusWrt router is very easy.

  • Download the proper Padavan firmware here. I used the latest “full” version RT-N65U_3.0.3.8-081_full.trx. Also download the matching .md5 file – you do not want to flash a corrupt firmware binary to the router. If you are on Windows, you may want to download Microsoft File Checksum Integrity Verifier to generate md5 from the downloaded firmware and verify it is not corrupt.
  • Before flashing the new custom firmware, save your current router settings. Go to Advanced Settings | Administration | Restore/Save/Upload Settings, then backup the current router settings to a local file on your PC. In case you need to revert your custom firmware back to AsusWrt, you will be able to restore the router settings easily with the backup settings file.
  • Installing Padavan firmware is considered “Firmware Upgrade”. You just need to go to Advanced Settings | Administration | Firmware Upgrade. From there you upload the Padavan firmware file (RT-N65U_3.0.3.8-081_full.trx), similar to this (courtesy to Ricky Gao, screenshot is for RT-N16):


  • Once router is flashed, reboot it, and enter the settings if they are different from your original settings. It should work the same way as AsusWrt now.

There are some more steps you may want to do.

  • Disable Telnet and Enable SSH. Telnet is not safe and SSH is better. You will need to use SSH often in hacking this router. P.S., this Padavan firmware is not affected by the Heartbleed vulnerability.


  • If you use Windows, install PuTTY if you haven’t. Using PuTTY as your SSH client connecting to the router, see here. When you connect to router SSH server for the first time, PuTTY prompts a message like “The server's host key is not cached in the registry...”. Just accept it. For details, check here.
  • Once you login to the router through SSH, you can now prepare to use Entware. The first step is to get USB storage for Entware packages, following instructions here. I use a USB thumb drive.
    • You do not need a swap partition on a USB drive, because USB drive is slow and not meant to sustain many writes. RT-N65U probably has enough RAM for most services.
    • Be careful when creating file system on a small USB drive such as 1GB or 512MB. The default command may create too few inodes. When many small files are installed by Entware on the partition, it can run out of inodes before the space is used up, and no more files can be created. You may want to change -i option when making file system.
  • Use Entware opkg to install software packages. For example, update Entware and install nano. The default editor in Padavan firmware is vi, which is too hard to use for anyone from Windows background. Gnu nano will be very useful when you edit the script and configuration files in hacking the router:
 opkg update opkg install nano 

That’s it at the moment. The router is now open to a lot of explorations!

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