What is Blackberry?
When BlackBerry first came out, the system was designed as a two-way pager with a real (not on-screen) QWERTY keyboard, which could receive and send email through its proprietary protocol and email relay service. Some time later, the system supported mobile phones service and a walkie-talkie service.
The next generation included a limited web browser. Nowadays BlackBerry supports third-party applications, a better web browser, Java, voice recognition; and usually comes with a built-in photo/video camera.
The BlackBerry OS is a fairly robust product although I trashed the system configuration not the OS itself of my first unit several times and practically destroyed the hardware of a second unit. The last model I used before I started using Android had version 18.104.22.1689 of the BlackBerry OS with kernel 22.214.171.124a no idea what these numbers mean in terms of the OS and its related technologies.
What has caught my attention is the resolution for such a small screen (about 2.5" in most current hardware) with a resolution of 320 by 240 (65,000 colors, not shabby at all) to watch videos, read e-books using Mobipocket or go on-line using Opera Mini, (instead of its default web browser) via its 802.11b/g connection.
BlackBerry is a pretty descent OS tightly intertwined to the hardware that it was written (coded) and/or configured for. Nonetheless I should point out is that once in a while you need to do a cold boot removing the battery to clean zombies (not to be confused with viruses) in RAM or memory overflows or other garbage data although it has Memory Cleaner (utility to clean up temporary data).
I have not studied the inner workings of the OS. As a matter of fact, I am not sure where I could read about it, but I should point out that some of these units are more powerful higher microprocessor speed and RAM than some of the desktops or laptops that I have owned. It is exciting having that much power in a device that fits in my hands.
Device Memory + Home + /Device Memory/ + Documents + Pictures + Music + Ring Tones Media Card + BlackBerry + documents + music + pictures + ringtones + system + videos + voicenotes + [user-defined subdirectories] + [user-defined subdirectories]
Note that the memory card (microSD) is mounted at the root as Media Card. Only in Media Card, the user has access to create, hide (changing attributes) and delete directories other than the ones needed by the system. Some program installations also write data to Media Card. In any event, mobile phones can be mounted as external disks via USB connection.
One thing that I find fairly strange is that notes, tasks, calendar, contact and all configuration data is stored in the mobile phone and not in the microSD not even transferable. In order to copy this data, one has to sync the mobile phone with a desktop using a proprietary code application. System configuration and user data are stored as a backup files, which can be used to restore the system or to transfer configuration files to another BlackBerry device.