Category Archives: Computer for Dummies

MacBook Pro 高Kernel CPU占用解决办法 (含iOS Catalina)

MacBook Pro when suffering from water damage (spilled coffee, for example), usually displays two symptoms:

  1. High CPU consumption by system process “Kernel” – usually in the ball park of 200-300%
  2. Consistent top fan speed

The first, in particular, renders a MacBook unusable, as almost all computational power is consumed by the Kernel. The Kernel process was designed to prevent high resource consumption by individual applications – but the gut feeling shows that this is yet another built-in feature to force users to bring a nevertheless perfectly usable back to the so-called genius bar to be fixed for a price, or better yet, replaced with a new unit altogether.

While the conscientiousness of corporate Apple is open for discussion, there are in fact ways to informally prevent such behaviour and restore the machine to a use-able state. Many blog posts (e.g. the most concise one I’ve read can be found here) Here is how:

First, the machine needs to be rebooted into Recovery Mode, by restarting while holding down cmd + R before the loading screen (white apple) shows. In this view, launch the Terminal and run the following command to disable System Integrity Protection (SIP), which is a built in feature of the iOS to prevent undesirable modification of system files:

csrutil disable

Then the machine can be rebooted, either into full operating system or into the Single User mode (which is faster, and quieter) by holding down cmd + S.

Here is where the trick needs to be adapted to Catalina: in this latest version of the iOS, Apple has introduced yet another layer of protection for the system files – they are stored in a read-only section of the drive, which prevents the removal of the undesirable system file that causes the blown-out Kernel issue.

In the Single-User view (effectively terminal only view), or in the full OS view with a terminal launched, run the following command to enable read/write mode for system files:

 sudo mount -uw /

Followed by the following command which removes the package extension file IOPlatformFamilyPlugin.kext that causes high Kernel CPU usage

rm -rf /System/Library/Extension/IOPlatformFamilyPlugin.kext

This in turn followed by a restart, or if in Single User mode then

 shutdown -r now 

Do remember to boot into Recovery Mode using method mentioned above, and rearm the SIP protection by running the following in Terminal

csrutil disable

In the case of some users, the fan would go back to normal – but if not, as in my case, an app Macs Fan Control can be used to slow the fan down according to the actual machine. There are many websites that lists regular temperature of a working MacBook Pro for various models. These can be used as a reference for setting temperature dependent fan speed of the machine.

Full Guide to installation of Windows XP on netbook using only a USB stick

Windows 7 Starter edition has been haunting my Dell 1012 for over a year. It is supposed to out-perform other operating systems and is strongly recommended by all the bench-marking softwares and experts of these softwares who write netbook  guidelines.

I’ve browsed too many blogs and commentaries where people have contradicting opinions about these operating systems. The simple fact is, Windows 7 Starter is simply not light-weight enough for a resource-limited device such as a netbook. The system’s constant CPU usage of 50% even when idle is unbelievable. Moreover, who’d imagine a browser like Chrome would take longer to boot than the IE (or occationally, MATLAB) on my home laptop?

Windows XP on the contrary, was developed more than 10 years ago and was designed for computers back then (when dual-core was alien and a quad or oct-core computer would certainly sound like alien invasion.) It ran smoothly on those devices — there is no reason to believe that they won’t perform better on our comparatively powerhouse devices, aka netbooks (quite an irony… ah, the beauty of Moore’s Law…).

Hence was my conclusion that Windows XP is the right option for my Netbook (Did I mention that it is a beautiful Dell 1012, with Intel Atom Processor @1.6GHz? And I have recently upgraded the RAM to 2GB myself. More on the RAM upgrade if people are interested enough). I am writing this blog on my netbook, which runs Windows XP Pro SP3 right now. Glad about that choice. Would certainly recommend anyone with a similar spec netbook to opt XP over 7 Starter.

Enough blabbering. Here comes the actual thing.

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To install Windows XP, which does not support virtual CD by itself, the easiest way is to use an external CD drive, which should be available on the internet for about 20 pounds (but who uses CD drive nowadays anyway?). The second best option I have come across (actually I searched all over the internet for it…) is to install XP using a USB stick (minimum 1GB required, though… but again, how many USB sticks nowadays is even vaguely less than 4GB…).

Make sure you have a CD or CD image of Windows XP available. If you use a CD image, you should load it into your vitual CD drive.

To start with, you would need three softwares:

  1. usb_prep8
  2. peToUSB
  3. bootsect

These will enable you to setup the USB stick as a booting device for your PC. You should be able to find them easily on google. But if you can’t and you absolutely need one leave a message here.

Insert the USB stick.

If you have a PC which already has XP installed. It’ll be much easier to use these tools, but if not, (say you have a PC running Win 7 or Win Vista, do not panick, here is how you can bypass some problems that you might encounter if you follow other Internet tutorials :p)

After download, unzip the files into separate folders. Copy the content of PeToUSB to usb_prep8 folder. Now, right click on all the exe files from these folders, select property and tick the box next to run as administrator, click OK.

next, instead of starting the usb_prep8.cmd program directly as told by other tutorials, here is the proper way of doing it on Win 7 or Win Vista:

Go to Start button, in search panel, type cmd; where the program cmd shows up, right click and run as administrator. Using ‘cd’ and ‘cd..’ command to navigate to the folder which contains usb_prep8, type usb_prep8.cmd and it should run in the cmd window

<Will insert a plot in the future>

The program PeToUSB should start automatically and identify your USB stick. Tick ‘Quick Format’ if it is not selected (or the next step is going to take you more than 20 mins to finish). Click Start. Format should be very fast.

Do not close the PeToUSB window or the cmd window previously opened.

Instead, open a different cmd window using the method mentioned above. Navigate to the folder containing bootsect. Type ‘ bootsect.exe /nt52 I:’ but replace I with whatever disk number your USB stick is on your PC. If everything goes well, it should say “Successfully installed bootsector onto your USB device” or something similar. Close this cmd window.

Now close the PeToUSB window and you should notice the first cmd window changed into a series of options from 0 to n (can’t remember how many options are there).

Basically just follow instructions from 1 to 4 and ignore the other options. Select 1 and enter the driver where you put your XP installation CD (or image); then select 2 and enter a lettter which is not currently used by any of your disk drives, the default option T: should be good enough if you are not nerdy enough to re-number your drives (logically, if you were, you would not bother to read this article anyway); select 3 and enter the drive letter of your USB drive. select 4 and ‘y’ and yes and accept all the options to follow: you should see XP installation files being copied to your USB stick.

After this your USB stick is a powerful booting device and you are ready to go!

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Next part is about the installation of XP.

First start your netbook with the USB stick plugged in. Press F2 (or whatever the corresponding keys that’s used on your netbook) to enter BIOS setting screen. Change the SATA mode from AHCI to AHA because AHCI is not inherently supported by stock XP (sadly). Change the boot order to USB first; Save and restart.

The netbook should now boot from your USB stick. select option 1 (which shows up as the second option…), text mode. If you did not change AHCI to AHA or some other modes, your hard drive would not be recognized by XP and you’d only have your USB stick as a possible partition.

Delete and format and ensure that there is only one partition available (Yes, the stupid XP installer does not recognize multiple partitions). Your netbook should restart and take you to the GUI interface automatically. Then install XP as you would do with CD installtions.

After a few steps, XP is ready to go. Next thing to do is to install all the drivers for your netbook. You should be able to find them from the netbooks’ supporting website.

Now you should be able to enjoy the smoothness of the light-weight yet still perfectly designed and tested system, Windows XP on your netbook!

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On a separate note, there is likely to be an issue with Standby mode: if your netbook goes into standby mode, it may not be able to wake up no matter what you do; this is because the SATA driver now is set to be AHA mode which does not normally support standby

Again, do not panic. get the SATA driver for AHCI from your netbook’s support website. But installing the driver itself is not as easy as installing those for other hardwares.

Unzip the installation files for the driver, it would not install automatically. Instead, you should go to Device Manager (right click My computer –> Properties –> Hardware –> Device Manager), select ‘ATA devices’ then ‘Primary IDE devives’, right click, select update driver; select specify the location rather than search on internet; select do not search; select ‘Have Disk’ and locate the driver files you have unzipped; follow instructions until the driver is installed. The computer would prompt to be restarted, do so.

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It is a long time since I wrote anything this long… Although it is likely that this post will help no one, it is still good to keep this tutorial as a sort of reference in case I’d need it in the future.

 

I’ll go do some proper work now…

Stay hungry, stay foolish.

 

2:13 am 10/02/2012

A Crash course on 'Wall tunneling'

This is a crash course for those who wishes to climb over the GFW of China.

Of course you wouldn’t be able to read this blog since it’s been blocked…… but anyway, here is a quick cheat sheet in case you have subscribed to my blog using google reader :p

First you will need Firefox browser with addon ‘Autoproxy‘. This add-on sometimes is baned from being downloaded in China, so you might want to try the chinese version of add-on directory.

After installation of add-on, you will be prompted to select the default connection method, set it to ‘Tor‘. You will also notice that you have subscribe to a list of website on autoproxy settings; these are the websites blocked by GFW. Now if you want to visit my site freely, either set Autoproxy to Global Mode or add a new rule for cenci.tk. You can also update your subscription manually from time to time when you find it difficult to get pass a certain website.

Next close firefox and install download from this website: https://www.torproject.org/dist/vidalia-bundles/vidalia-bundle-0.2.1.28-0.2.10.exe

Note that if you are typing the address in browser yourself make sure you use ‘https‘ such that your visit is encrypted. The non-encrypted http connection is blocked by GFW.

Exclude ‘Torbutton’ from the list of components. (you can also install it, but I have not tried using it, it’s another firefox add-on of similar function). I personally find autoproxy more ‘intellegent’.

Next we need to configure Tor with nice graphic interface provided by Vidalia. Open this webpage https://bridges.torproject.org/ or send an email to [email protected] using a trusted email provider (such as Gmail). Refrain from using QQmail and other mail service providers from mainland China especially because your mails can be monitored.

You will receive a list of bridges which look like below:

bridge 82.103.128.2:9090
bridge 86.171.137.27:443
bridge 69.145.49.200:443

If the progress bar on Vidalia freezes for a long time without completion, we need more detailed configuration of the software.

Open up Vidalia and go into Settings, go to Network option and select ‘My ISP blocks connection to Tor network‘. Add the bridges you obtained to the list shown below, do not include the text ‘bridge’; your added bridge would look like:

82.103.128.2:9090

Put all three down in the list, the order is not important. Now restart Vidalia but selecting ‘Exit‘ then start the program again.

You will see that Tor has successfully connected to a Tor network after a few seconds. You are good to go!

Please also remember to deselect option’My ISP blocks connection to Tor network‘ if you have problem connecting to Tor network a second time.

Note that Autoproxy is just a software which selects which site you visit that Tor is required. If you want full anonymity of browsing, set Autoproxy to Global Mode.

Enjoy browsing the internet outside the wall!

一个有意思的小教程

嗯哼~ 随着windows 7的推出越来越多人开始使用win 7,有个很有意思的新功能觉得很有意思,可以和大家分享一下;

首先呢你需要有一个windows live的账号,这就给你了Windows Live Skydrive的访问权利 (最近浏览器访问有点儿不太正常来着)。

打开Skydrive主页,大家在浏览器的地址栏会看到一个\\cid-1234567890abcdef.skydrive.live.com

这个红色的部分根据用户不同而变化,这个就是你skydrive的用户号码啦,窗口不要关,以后会用到

大家使用Windows 7的文件浏览窗口的时候一定会看到一个按钮吧,

我们可以用这个功能把Skydrive中的文件夹Map到本地,这样大家就都有25G的云储存器啦 :) 可以随时在本地打开任何上传到网上的文件,可以直接修改什么的,比Google Docs还方便,哇咔咔!

点开Map network drive之后,可以看到下面这个窗口:

在Drive选项里可以选择任何自己希望Map的磁盘号,这个对最后的结果没有影响;

在Folder的位置填入

\\[email protected]\1234567890abcdef\XYZ

其中红色这个部分填的是我们上面skydrive的用户号码,然后蓝色部分就可以填写我们想要map的文件夹。比如我在skydrive网站上建立一个叫Local_Access的文件那么整个folder的地址就是:

\\[email protected]\1234567890abcdef\Local_Access

然后OK就行了,之后Windows会提示登录Windows Live,输入用户名和密码就可以看到自己的Skydrive出现在硬盘列表里啦! :)