matsu

Huawei E180 vs. MacBook Air

Before / After of the modification of a Huawei E180 to fit a Macbook Air directly

I bought a Huawei E180 3.5G modem (TMN) to use with my MacBook Air, just to find it wouldn’t fit directly into the Air’s recessed USB port. A metal file and 20 minutes of light work later, it does fit in the port, and it works!

memory vs. storage architecture

The clear distinction between memory (RAM) and storage (HDDs) has suffered an evolution in the past few years, in part because of the technologies, but also because of the way the operating systems work. The current state of affairs goes something like this:

• Cache memory – a faster copy of parts of the RAM of the system, keeping the most used instructions and data “nearer” (in terms of access speed) to the processor
• Main RAM – memory where the whole current state of the machine is kept and manipulated
• Video RAM – memory where the image display state resides (which might reside in the main memory in terms of hardware)
• Virtual Memory – the opposite concept of cache memory – the operating system moves less used data into the slower non-RAM storage system, to free the main RAM memory for the most used data.
• Storage – bigger, slower, non-volatile memory where the non-working state of applications and data is stored, even when the computer is turned off, which is divided into three main technologies:
  • Hard disk drives – magnetic media on spinning platters – cheaper than RAM, more compact by capacity, much slower, less reliable (to impact and wear and tear), but non-volatile
  • Flash memory – solid state memory (like RAM but non-volatile), more expensive but faster than HDDs*, more reliable, some limitations on the total number write cycles possible, the best energy efficiency of all the available storage technologies
  • Optical storage – CDs, DVDs, much cheaper than any other kind of storage, not very energy efficient, slow

Although there has been a constant evolution of all these technologies, the evolution of price/size/speed of flash storage has brought it to the point where HDDs can be replaced by flash storage, although still at smaller capacities and much higher prices. But the trend continues to march on, and based on that evolution I think a possible evolution of the state of the art in memory vs. storage architecture design could go in the following direction, both for mobile and non-mobile applications (with the tweaking of the wanted ratio between capacity/performance on one side versus the need for portability/energy efficiency on the other):

• processor cache memories, main, and video RAM as they are today
• virtual memory to be ran on slower but cheaper RAM (although faster than storage of any kind), at the same price point as flash storage, but volatile – the virtual memory contents could be copied into storage on suspend/hibernation states – which would in part reduce the problem of the potentially limited number of write cycles on flash storage
• HDD spinning platter storage to be replaced by flash memory, in two stages:
  • at first, there could be an hybrid system, where the main OS and applications would work from a flash storage based partition, and the main data storage would still be on traditional HDDs (there are hybrid drives today, but I propose a less integrated and less OS dependent technology)
  • the second stage would be when the price per MB of flash storage achieved a level compatible with the needs of users (to be achieved for mobile applications first), and traditional HDDs would be phased out almost completely
• Same line of thought for optical media vs. flash storage, or the appearance of large capacity solid state ROM storage (although my opinion is that the WAN or LAN online transmission of free or paid data will replace the distribution by physical media completely, eventually)

To give a real life example, the default partition arrangement of general usage Linux installs (boot/swap/data) would be based on three different technologies – flash storage for the boot partition, cheaper RAM for the swap (virtual memory) partition, and traditional HDD technology for the data partition, until flash technology is able to overcome its limitations both in terms of price and no limitation on write cycles, and replace the other two technologies.

* in some applications fast HDDs in sequential data read/write operations can be faster than flash storage

If you’re reading this…

…it means that the latest matsu home move has been successful.  Matsu is running in the original XP install, but now running under VMWare Fusion on my Mac Mini, meaning that I’ve shutdown my last Windows non-virtual machine.  I’ve been meaning to do this since the first of Fusion’s beta releases, but it was impossible (or very difficult) to do it, as the first release didn’t support ethernet bridging of the Airport (wireless) connection.  This latest version seems a little faster, and it also adds support for DirectX, and even Vista will run on it.

Copy/Cut/Paste on the Nokia E61

The Nokia E61 doesn’t have the edit key (the one with the little pencil)  like previous S60 phones, which was used for copying and pasting text.  To copy and paste, select the text with either of the shift keys plus the joystick, and then use the ctrl (control) key plus (you guessed it) “x” to cut, “c” to copy, and “v” to paste.  Very simple, but I couldn’t find reference to it anywhere I searched (PEBKAC probably).

Charging backpack

Here’s how I put everything in place so I can charge my MacBook Pro and my Nokia cellphone while driving or riding my motorcycle without removing anything from inside my backpack. No modifications needed!
You’ll need:

• a backpack – mine’s a Samsonite, completely indestructible
  
• a (good) power inverter – I use an APC Travelpower – 75w
  
• a 3-way plug adapter
  
• the chargers you will be using (the cell phone charger is harder to remove from the backpack, as it stays with the inverter in the closed inner pouch)
  
• a cable to connect the 3-way plug adapter to the laptop charger (not pictured)
• some kind of tape to firmly connect the 3-way plug adapter and the inverter (not pictured)

Here is how you put everything together:

1. Study the internal layout of your backpack, find where the inverter should go (preferably a zippered pouch), and some open pouches for the cellphone and the laptop charger.
   
2. Attach the 3-way plug adapter to the inverter using some tape, so it doesn’t come loose with the all the movement, connect the cellphone charger and the cable that will connect to the laptop charger, in the flattest configuration possible. Wind the excess cable around the 3-way plug so the ends of the cables can just reach the right places.
   
3. Put the inverter/plug adapter/cellphone charger in the enclosed pouch, routing the cables to where the zipper ends.
   
4. Put the laptop charger in place (where it’s easily removed, so you can use it “normally”), and find the place for the cellphone. Make sure that the laptop charger cable can reach your laptop (which you should stow in a way to make the charging port accessible).
   
   
5. That’s all! When you’re driving (or riding your motorcycle, if you have a 12v socket where you store your backpack – a future modification I’m doing on my Yamaha Majesty), you just have to fish the inverter cable out to connect it to a 12v socket, and all your hardware will get the juice it deserves with no fuss, and no entangled cables! If you have a bluetooth handsfree car kit/headset, you can even use your phone without even opening the backpack.
   

Important note: make sure the inverter has enough power to charge everything – in this particular case, although my inverter is rated for 75w, and the MacBook Pro charger is 85w, it will not consume that much if it’s just charging a sleeping/turned off computer, leaving more than enough margin for the ±5w cellphone charger.