Person.h

In the code below we define the interface of the Person class. Notice the NSCoding protocol in the interface header.

@interface Person : NSObject <NSCoding>
{
     NSString *firstName;
     NSString *secondName;
     NSString *phone;
}
@property (nonatomic, retain)NSString *firstName;
@property (nonatomic, retain)NSString *lastName;
@property (nonatomic, retain)NSString *phone;

Person.m

In the code below we can see the person implementation. Notice the implementation of the NSCoding protocol. We have to implement two methods, encodeWithCoder and initWithCoder. We tell the NSCoding protocol that we want to decode and encode all of the person’s members. We give the objects keys in the first method so that we are able to find them again later when we decode.

@implementation Person
@synthesize firstName, secondName, phone;

- (void)encodeWithCoder:(NSCoder *)encoder {
    [encoder encodeObject:firstName forKey:@"firstName"];
    [encoder encodeObject:lastName forKey:@"lastName"];
    [encoder encodeObject:phone forKey:@"phone"];
}

- (id)initWithCoder:(NSCoder *)decoder {
    if (self = [super init]) {
        self.firstName = [decoder decodeObjectForKey:@"firstName"];
	self.lastName = [decoder decodeObjectForKey:@"lastName"];
	self.phone = [decoder decodeObjectForKey:@"phone"];
    }
    return self;
}

Saving and loading an array

In the code below we populate an array with two person objects, then we save the array to disk and afterwards load it.

// Create two person objects
Person *person1 = [[Person alloc] init];
person1.firstName = @"Peter";
person1.lastName = @"Peterson";
person1.phone = @"12345678";

Person *person2 = [[Person alloc] init];
person2.firstName = @"Andrea";
person2.lastName = @"Peterson";
person2.phone = @"12345687";

// Put them into an array
NSArray *array = [[NSArray alloc] initWithObjects:person1, person2, nil];

// Save the array
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
                                                     NSUserDomainMask, YES);
NSString *docDir = [paths objectAtIndex:0];
NSString *fullFileName = [NSString stringWithFormat:@"%@/ourArray", docDir];
[NSKeyedArchiver archiveRootObject:array toFile:fullFileName];

// Load the array
NSMutableArray *arrayFromDisk = [NSKeyedUnarchiver
                                 unarchiveObjectWithFile:fullFileName];

Conclusion

Follow this tutorial if you want to save your arrays or dictionaries to disk for later use. Following this method is very simple and it actually works. I’ve read alot of different tutorials on the web, most of them suggest storing your objects either as .plist files or by using SQLite. I think following this method is both easy and efficient. Read more about the NSCoding protocol here.

EDIT: There was a bug in my code. fullFileName was missing %@/ in the stringWithFormat message.

My task in this project is to build a system that makes information available, and handles context awareness. I am also building a prototype application which utilizes this system. The prototype is a bus application that runs on the iPhone. The main objective of this application is to receive route information based on the users current location.

The deadline for my master is 15th May 2010. There is of course a last exam where I must defend my thesis during a public presentation and a following closed oral examination. I will put my master out in to my portfolio when its history.

Anyways, ProISP is cheap and very good. Take a look at their homepage ProISP.no for more details.

Dpreview (Digital Photography Review), which is the best review site for photo equipment in my opinion, have benchmarked the 18-270mm lens, the test can be found here. I will make a decision soon. A personal review will of course be posted on my amazing blog. Stay tuned!

I’m going home to Mo i Rana 10th june after the “Advanced Database Systems” exam. I start working the 15th june at the National Library (Nasjonalbiblioteket) in my home town Mo i Rana. I don’t know what I’m going to do, but at least it’s some IT related stuff.

I have decided to “publish” the papers I have written this semester. You can find them in the list below with a short description. Enjoy. They are not that long.

• “Face Recognition” – The paper was written as the second mandatory assignment in the “Advanced Database Systems” course. The paper is a survey type of paper. It sums up the different techniques used for detecting and recognizing faces in images. It is a very interesting topic.
• “Supporting Mobility in Content-Based Publish/Subscribe Middleware” – This paper was written as the third mandatory assignment in the “Middleware” course. This paper is also a survey kind of paper. It sums up different techniques on how it is possible to support mobility in publish/subscribe system. Interesting read.
• “Optimizing Hadoop for the Cluster” – This paper was written as the second mandatory assignment in the “Advanced Distributed Systems” course. In this paper I describe how we can optimize Hadoop for its cluster. The experiments conducted shows that tweaking the default configuration gives two times smaller job-latency. Very interesting paper this as well.

So thats an update for now. Have a nice summer. I will try my best to write more posts during the “vacation”. So stay tuned.

I have gathered some links to other blogs/news-sites if you’re interested in more reading.

Some good sourced in-depth articles:

• Arstechnica’s talk about the release candidate.
• TG Daily, high-level talk about new features.
• Lifehacker’s first look at the beta.

Who doesn’t like an operating system that boots and opens FireFox in approx 25 seconds?

I still don’t have a chosen problem for my master thesis. Hopefully I’ll have it ready before the summer. I’ll see you later innovator!

Before you start

Before you start installing OS X you should know about a couple of things. First off, if you have questions search the web. I have found all my answers and tutorials at the Insanelymac forum, I recommend it. That site is a great resource. But remember, search through the forum before you post your own problem.

If you have important data on your computer you should create a backup. The chance of ****ing up your computer is big.

Do not blame me for things that doesn’t work for you. Use Google or a forum to find your answer. You should know what your doing. Troubleshooting requires computer skills whether you like it or not.

What is going to work after following this tutorial

This is a list of hardware components that I have currently been able to get working.

• Video – Nvidia GeForce 8600M GT 512MB
• Sound – ALC-268
• Ethernet – BCM5787
• Keyboard
• Mouse
• Hard drive
• DVD-ROM
• USB

The most important piece missing here is off course the Wireless card. There are two projects going on now where they are trying to develop a driver for the Intel 4965 AGN wireless card. The most promising project, in my opinion, is “Project: Camphor”. Check out the link for more info about it. I think that project has a lot of potential, but we’ll see. If you need a Wireless card you should buy a USB Dongle. I have tried the Ralink RT2500 chip, but the driver gives me kernel panics all the time so I have to stick with the ethernet. I think the SMCWUSB-G card is the best shot at getting wireless at the moment. (Search on google for product information).

Just to mention it, overheating may become a problem. I have struggled a lot with overheating. What happens is that the CPU fan simply doesn’t start. Once you got access to the internet you should download and install Temperature Monitor. So if you can hear that the fan isn’t running, the computer will eventually shutdown itself. I don’t know how to fix this but a lot of laptop owners seem to have this problem.

The installation

First off you need to have an OSX Leopard (iPC 10.5.6) disc. Boot up from that disc. When you have selected the partition where you want to install OS X you need to select some drivers before you can start the installation itself. If you haven’t created an OS X partition use disk utilities to do so. Here’s a list of what I chose to install. Remember this worked for me, it doesn’t mean its going to work for you.

1. Language – Select a language package if you like.
2. Kernel – You need to select a kernel. There is not selected any kernel by default so you have to choose one. I chose to install the netkas sleep kernel.
3. Graphics card – You also need to select a driver for your graphics card. I have a GeForce 8600 M 512MB. I chose to install the NVDarwin 512MB. If you have a 256MB card you should select NVDarwin 256MB.
4. Keyboard and touchpad – In order to get your keyboard and touchpad working you have to choose the PS/2 Keyboard Fix. Do not install the PS/2 Mouse Fix, the keyboard package will fix both.
5. Seatbelt.kext 10.5.5 – You have to install this package as well. If you don’t do it you wouldn’t be able to mount .dmg’s.
6. Applications – You should install some applications too because we will be doing some operations later when you have your installation up and running. Install these applications: Kext Helper B7 and NTFS-3G + MacFUSE. Remember its not dangerous to install other applications.

When you have selected these packages you can continue and start the installation. The installation will probably take about 30 minutes. Remember before you start that the bootloader you have will be replaced by the default OS X bootloader. You can select Chameleon bootloader if you like. I have no experience with that bootloader. I’m using grub myself. Don’t be afraid, if you are using grub you can always get it back if you mess it up. Read my post about this topic here. So that’s it for the installation. Hopefully everything works out fine for you.

sound and ethernet

So if your installation finished successfully you may continue here. Boot up OS X. We’ll start installing the audio card.

The ALC-268 installation

First off, I followed the guide over at Insanelymac to get this working. This is just a copy of that guide. The files you need are located here. Download the file and unzip it.

1. Run ALC268Installer 2 or 1. The one that exist in the .zip file will work.
2. Delete /System/Library/Extensions/ALCInject.kext. Use the terminal. You should know how to remove files.
3. Restart.
4. Use Kext Helper b7 to install HDAEnabler.kext. Drag the HDAEnabler.kext into the Kext Helper window.
5. Fix Permissions with Disk Utility.
6. Restart and make sure that Internal Speakers is selected in Audio Settings.
7. Then run HDA Fix v3 (IMPORTANT: Riavvia in seguito means Restart later, Riavvia means Restart now).
8. Click Restart Later.
9. Repair permissions with Disk Utility.
10. Restart.
11. Bootup and sound and shutdown should work.

If shutdown doesn’t work you should try doing it over again.

The bcm-5787

Same goes here, I followed this guide over at Insanelymac to get this working. Download this file.

1. Simply install the .kext using Kext Helper B7.
2. After that plug in your cable and run this command in the terminal.

sudo tcpdump -i en0 &

The tcpdump process must be running to get this to work. There are workarounds for getting this to work automatically but I haven’t tried it out. Read the readme.txt file in the .zip archive for more information or check out the Insanelymac link that I provided earlier in this section.

summary

This tutorial will get you up and running with most of your hardware. The only big thing missing is the Intel wireless card working. But give it some time, it will be supported later this year I believe. I’m visiting mercurysquad’s blog every day just to check the progress. The Compal IFL90 is able to run the retail Leopard DVD, the computer can run the Vanilla kernel which is the default kernel in OS X Leopard.