Dependency Hell

A software dependency isn't like a drug dependency -- it doesn't mean you can't survive without a software fix. It can actually be a lot worse. A software dependency is when one program -- the one you need -- depends on another program -- one you probably don't know exists.

Dependency Distress
You load the software you need, but it doesn't work. Turns out it can't work without help from some other program. Worst case? It takes you forever and a day to figure out what elusive bit of code your program needs to operate, then you start the process of finding and installing it. Then you find out that the code on which the program you need depended on has a dependency of its own.

And somewhere along the line you discover that one of these "dependencies" is actually a specific version of some obscure bit of code, not the one you found.

This is called dependency hell. And that's a complement to the devil. Like most circles of software hell, this one started out as a way of making things easier.

Any substantial program is made up of a bunch if different processes. Some of those processes are used over and over in lots of different programs. It doesn't make sense to rewrite those common processes for every new program, instead programmers just drop in a link to an existing bit of code. These frequently-used bits of code, when they're organized into a group, are commonly called libraries.

DLL Hell^®
Microsoft tried to fight its way out of dependency hell by creating a system called DLL, for dynamic link libraries. With DLLs, Microsoft was able to escape the dependency circle of software hell and -- this is innovative -- create a new circle called "DLL Hell." I capitalized it because I like to think of it as proprietary: Microsoft invented this particular circle and, as far as I know, owns the rights to it.

In short, DLL became a Hell because the little bits of code in the library could change without changing the overall library. Why's that bad? You install some new software, it replaces the old DLL with a newer, slightly changed, DLL and gets to work. That's fine, for a while.

When you try to use some other program, it calls on the DLL it's always relied on, finds that the bit of code it needs has changed, and returns an error message: something about not being able to find a required DLL file. After much anguish, you reinstall the program and replace the newer DLL with the older one. Now your old program works fine but ....

Yeah, that's why they call it hell. Makes rolling a rock up a hill forever seem almost pleasant.

Cycles, Chains, Trees and other Metaphors of Dependency
Once you're in a circle of hell, you find it has its own subdivisions. Dependency hell is no different. Some dependencies are circular and continue along a curve until they wind up trying to reuse a bit of code that's busy because they're already using it. The problem is as awkward as that sentence describing it.

Some dependencies seem to trace backward along a line that ultimately leads to a guy sitting on a rock with an abacus -- or maybe even an inchoate idea of what an abacus could be.

Some dependencies branch off endlessly as if Escher had designed a tree.

For those of us who aren't archaeologists or theologians of software hell, the result is fairly consistent: our computer won't work and we're late with the report/tax return/homework/online reservation and it's going to ruin our career/life/chance of getting into Harvard/date.

Moving toward Stasis
One way to avoid dependency hell is an increasingly-affordable form of purgatory. Think back to DLL Hell. The problem there is the first "D." It stands for "dynamic" and it means that the library can change independently of the software that uses it. That's efficient because you don't constantly have to change one (library or software) every time you change the other, and because you don't have to repeat all of those reusable bits of code. It's inefficient because it doesn't work, for the reasons stated above.

The solution? SLL, for static linked library. I don't think it's really called that, but it describes the solution reasonably well. You install a library of commonly-used code and a bunch of programs link to it -- but statically. The library doesn't go away as long as any other software is using it, and the software never links to a different library.

That avoids all the cost of linking to changed libraries that won't work with various versions of software. It comes at the cost of having to keep additional libraries on your computer. But hard drives are getting bigger and cheaper at the same time and it's a small price to pay for a way out of hell.

sudo apt-get God
I'd like to tell you that's Latin for "God helps those who are just trying to finish a report/tax return/homework/online reservation so they can have a decent career/life (outside of prison)/chance of getting into Harvard/date." But it's not.

In fact, it's not even Latin. Or English, as far as i can tell. It's the way some versions of Linux try (pretty successfully) to keep us out of dependency hell.

It started with Debian, an early easy-to-use version of Linux that has branched off into, among other 'distros" Ubuntu, the Linux I use. From a user's point of view, it starts with a program called apt-get.

To install a program in Ubuntu, you type into the terminal: sudo apt-get install [name of the program]. The "sudo" part gets you permission to make changes to the operating system; "apt-get install" instructs your computer to get the program and its dependencies and install them; "name of the program" says what to get and install.

The key to making this all work dependency-wise is something that's slightly behind the scenes. Before you can use apt-get, you have to tell it, in a general sense, where to get it. The where, in this case, is a place called a repository.

Mobile Phone ID Numbers

Soon after you start hacking your phone, you're going to run into ID numbers necessary for various things. Here's a quick rundown.

IMEI
IMEI stands for International Mobile Equipment Identifier. If your on a UMTS or GSM network (e.g. AT&T in the U.S.) it's the number that identifies your phone -- mostly to the network, but also for things like identifying a stolen phone, resetting the security code and generating the unlock code.

The IMEI is part of the phone's hardware; it's not on the SIM and changing the SIM card won't change the IMEI. (The SIM card has a different ID number, called an IMSI, which is more for identifying you or your account with the wireless company).

When I was trying to get a phone unlocked in England, someone told me it's illegal there to change an IMEI.

The IMEI has 15 digits. You can sometimes find the IMEI on a sticker under the battery or by going through menus for the phone's setting (or something similar. On Nokia phone you can see it by entering "*#92702689#" (without the quotation marks). On other phones, you can get the IMEI by entering "*#06#" .

The IMEI is for UMTS and GSM phones.

ESN
CDMA networks ID phones using an Electronic Serial Number (ESN).

ESNs have to be in hexadecimal and they're 32 bits long. Those 32 bits aren't enough to handle the explosion in mobile phone use, so ESNs are being replaced on CDMA networks by a new number called an MEID.

MEID
These are the new numbers for identifying phones on CDMA networks. They're 56 bits which I think allows for quadrillions of phones.

Quick Notes

Finding fast ways to take notes is an obsession. I'm always looking for new ways to take, keep and keep organized different kinds of notes. Here's one for general information that you want to remember.

Google Docs
It assumes you use Google Documents and Firefox.

• In Google Docs, create a document called "Notes," or something like that.

• Bookmark it and save the bookmark to your Bookmarks Toolbar Folder.

• It should show up on your toolbar as Notes - Google Docs (If you named it "Notes")

Anytime you want to make a quick note, click on the bookmark and write it down. Be sure to hit Save or Ctrl+S to save your notes.

But wait, there's more.
If you want to make a quick note while you're using the keyboard, there's an easy way to do that too. You can use Firefox's autohotkey feature to open your notes pay fast.

• Click on Bookmarks

• Go down to Bookmarks Toolbar Folder and then to your Notes - Google Docs bookmark

• Right click on the bookmark

• Click on Properties

• In the Keywords box enter a letter or two (I use n for notes).

• Click Save Changes

Now you can quickly open the notes page from your keyboard. Here's how:

• Hit Ctrl+L (which moves you to the Firefox url bar)

• Type n (or whetever keyword you created)

• Hit Enter.

Your notes page will open.

But wait, there's even more.
Really.

When you were entering the Keyword into your bookmark's Properties box, you might have noticed a checkbox with "Load this bookmark in the sidebar" next to it. If you check that box, when you use the bookmark to open your notes page it will open in Firefox's sidebar -- a handy place to take a quick notes while you're reading a web page. This doesn't work with the Ctrl+L keyboard shortcut.

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Make Extensions Work in Latest Firefox Version

I'm using Firefox 3. Version 3.0a8 to be exact. Why? No, it's not that I couldn't stand the anticipation anymore. I needed to cut and paste a table in Google Docs.

There's a bug in previous versions of Firefox that prevents cutting or copying the tables. I couldn't find a way to fix it, so I upgraded. The good news is that cutting or copying tables in Google Docs works fine.

The bad news is that all of my extensions stopped working. Since Firefox 3 isn't out yet (at least not officially) it makes sense that extensions wouldn't be updated to work on it. Sensible or not, it isn't very convenient.

Actually this happens a lot when a new version comes out. At least a couple of the extensions I use don't get updated for a while.

That doesn't mean they don't work -- they usually work just fine. But extensions usually have a line of code that checks to see what version of Fireox is running. Just to avoid any problems, the extension is programmed not to work if it detects a Firefox version later than it's been tested on. To get it working, all you have to do is disable the checking.

You can do it by disabling the checking feature in Firefox, or by changing the latest version number in the extension, but there's an even easier way. It's another extension called Nightly Tester Tools.

The extension is designed to let people test new versions of Firefox, but part of that process is getting extensions to work. Here's what you do:

• Download and install Nightly Tester Tools the usual way.

• After you've installed it, restart Firefox.

• When Firefox restarts, click Tools --> Add-ons.

• Click on the new button that says: "Make all compatible"

• Restart Firefox

Any of your extensions that actually work with the new version of Firefox will start working again. It should be most of them. It's possible that forcing an old extension to work in a new version could cause problems, but it's never happened to me.

I've forced at least one extension to work each time a new Firefox comes out and the worst result has been that the extension still didn't work.

By the way, Firefox 3 is nice. You can install it from Softpedia. It's still in alpha testing, but it seems to work fine. The only problems I've had is that some estensions don't work even with Nightly Tester Tools.

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FasterFireFox

Or at least smaller.

If you use Firefox a lot and have a lot of add-ons, you've noticed that it can get kind of slow. Check your Process list under Windows Task Manager (ctrl+alt+delete then click on he Process tab)and you'll see that it takes up a lot of memory. It's using more than 300MB on my system right now.

Some people criticize Firefox for its size, but that's kind of unfair. It offers a lot of options and if you add-on a lot of them, of course it's going to get big. My 300MB at the moment includes two windows each with a half-dozen or more tabs.

In any case, here's a way you can save some memory space, at least when Firefox in minimized and possibly when it's open too. It comes from CypherHackz.

1. In the Firefox address bar (the place where you usually type http://www.somesite.com) type about:config. Nothing else, no http or anything, just about:config. Then hit Enter, or click the green arrow.
2. A page will open with a long list in it. Ignore the list, put your cursor on some white space in the page and right click. A little box will open up with a few options. Choose New. Another box will pop out from New. Choose Boolean.
3. This will get you -- guess what -- another box. But this box has a place to type. Type in: config.trim_on_minimize then click OK.
4. Yeah, another box. Choose True and click OK.
5. Close Firefox and then launch it again.

Here's what should happen: Firefox will still use a lot of memory, but if you minimize the window, it will clear out a lot of space. It can drop down to 10 or 20MB.

That's a big help if you're trying to work in another program with Firefox minimized. An added benefit is that when you open up the Firefox window again, it doesn't jump back to it's original size in memory. In fact, it may stay significantly smaller for some time.

What to Remember about Memory

It seems like it's always a good idea to add memory (RAM) to your computer. Trouble is, memory comes in so many forms, it's hard to remember them all. And any memory you add has to be compatible with your processor and the memory you already have.

For desktop computers memory looks like the picture on the right. There are a few different form factors (sizes and shapes), and sometimes the modules are covered with a heat sink, but the picture gives you the general idea.

Memory
Memory is shorthand for random access memory or RAM. It can be confusing, because your hard drive is also a form of memory, as is your USB drive, memory stick, SDD, etc. Generally the term memory is used for the RAM in your computer, but context is key to being sure.

RAM stores the data your processor is using at the moment. It's relatively small, but fast. That's important, because anytime your processor is waiting for the data it needs, your computing is stalled.

In the overall data storage scheme, RAM falls between cache and the hard drive.

Your hard drive stores all of your software and most of your data (documents, music, etc.). Hard drives are big, but they're relatively slow so they're not good for holding data your processor needs instantly.

Cache is a small amount of memory built right into your computer's processor. It keeps things moving by putting the most urgently needed data right at your processor's fingertips.

RAM holds the data that the processor has called up from the hard drive, but hasn't been loaded into cache. Like the cache, it's volatile, meaning it loses all the data when you turn off your computer. Like the hard drive it can hold a fair amount of data. (OK, the "like the cache" sentence is dead on. The "like the hard drive" sentence is a bit of a stretch, but it kept some symmetry to the paragraph. You may have a couple of gigabytes of RAM, but probably more than a hundred gigabytes of hard disk capacity).

Memory modules almost always slide into slots on your computer's motherboard. It's simple and obvious on most desktop motherboards. On laptops it can be anywhere from simple to a freaking nightmare. I once used a computer than had its memory soldered onto the motherboard and no room for any additional modules. I like to think it was a one-time mistake that no computer maker has ever repeated.

In this article, by the way, we're talking about computer memory. That's important because memory with similar names and shapes shows up in printers and other devices and it can have some important differences.

Here's a short field guide to memory:

Form Factor is IMMportant
If you want to add memory to your computer, the first complication you'll encounter is the type of module -- form factor in industry jargon. To make identification easier(?) the various typ0es all have similar names, like DIMM, RIMM, SIMM and so on. Actually, they all sound alike because they're all memory modules (MM) and the chips on them are inline (I), so it's the first word (letter) that distinguishes them.

DIMM
DIMM stands for Dual Inline Memory Module. It's the most common memory around these days. DIMMs are the next step after 9you guessed it) SIMMs, or single inline memory modules. Why the change? Computer processors went from 32-bit data paths to 64-bit data paths. That's twice the capacity to access data and DIMMs let your 64-bit processor get all of the data from a single chip. A 64-bit processor connected to SIMMs would have to read two separate memory module at the same time.

DIMMS have 168 pines running along the bottom, separated into two groups of 84. There's a notch in between the two sets. The chips are mounted above the pins and they're separated by a gap on the board. DIMMs can have two groups of 4 chips or one group of 5 and oen group of 4, for a reason we'll get to in a moment.

SO-DIMM
Small-outline dual inline memory modules are -- you see this coming -- smaller than regular DIMMs. These show up in laptops where they help keep the overall package small. The price of that extra smallness is, we'll, price:they cost more. Be careful, though, because your laptop might use an even smaller module.

Micro-DIMM
Smaller yet, and even more expensive.

SIMM
If you need to add SIMMs to your computer step back and take a look at the big picture. I'll be blunt: you're computer's getting up there in years and it might not be worth the investment.

But I know how it is with the old workhorse that saw you through those pre-XP Windows days and never gave up no matter how many blue screens of death it had to endure. And besides, SIMMs are dirt cheap, even free if you don't mind digging through a dumpster.

Your SIMMs have 72 pins running along the bottom (OK, it could be 30 but if it is, you need to consult with a Hospice).

RIMM
Rambus inline memory modules are notable because they don't fit the profile, literally. They were developed by a company called Rambus and they have a proprietary design. My impression is that they don't come in computers anymore, they're used in other electronic devices that need memory.

Some Tech Terms

• Parity, non-parity and ECC (error checking and correction) all refer to ways of checking for errors in a stream of data, or not. Parity and ECC add a bit (literally) of data to the stream to detect errors. For the parity process it means adding a little more memory (on some DIMMs it means a total of 9 chips -- one group of 5 nd another of 4). The ECC process just slows the memory down a tiny bit, not enough to wipe out the extra efficiency of eliminating errors. Non-parity memory doesn't check for errors.
• Buffereing is a way to make the exchange of data with the processor more efficient.
• 
  

So What's in Your PC?
OK, now you know what kinds of memory are out there. But what's in there (your computer, I mean)? Well, you might remember seeing the time of RAM on the box. You could take apart your computer and look at the modules (which is the right thing to do before you invest in any more modules)?

But if you want to find out right now in kind of a cool way, you can download
some free software that will examine your computer and report back. It's called CPU-Z. You don't have to install CPU-Z, just download it, unzip it and double-click on cpuz.exe. A little windows will open up. If you click on the "Memory" tab at the top, you'll see what kind of RAM you've got. (If that last sentence sounds a little in-your-face, it's because it is. RAM matters).

It won't take but a second for you to see that there's an opportunity to waste some time here. CPU-Z can tell you a lot about your system -- even more if you read the readme file that comes with it.

But before you wander off, the tab next to Memory is important too. It's labeled "SPD." Remember that your motherboard has slots for memory -- probably 4 of them. Since memory modules come in different configurations, e.g. 512 MB, 1 GB, etc., you have to figure out if you have any open slots. The SPD tab will tell you how many slots you have and what's in each of them, if anything.

If your computer currently as 2 GB of memory, it could be a 1 GB module in slot 1, a 1 GB module in slot 2 and then 2 empty slots.

You could add a GB by slipping a new module into the third slot. But if your 2GB comes from 4 512 MB modules taking up all 4 slots, it's more complicated. Most online memory stores have help in figuring out the best configuration. Just Google "memory."

Great WordPress Widgets: Navigation

WordPress is amazing; of course it's great for blogging, but it's also a terrific content management system. One catch, though, is that it's not really set up for navigating static pages. That's why the NRS Folding Pages Widget is such a find. It's easy to set up, easy to use and fairly flexible. You can download it here.