bomb(redirected from explosive device)
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(1) An archaic name for an artillery projectile. In smoothbore artillery the term “bomb” or “grenade” refers to a projectile consisting of a spherical, hollow, castiron body, a black powder charge, and a wooden tube with a compressed powder compound. The bomb charge would explode after the time train was ignited. From the 19th century in Russian artillery, projectiles with a mass of more than 1 pood (16 kg) were called bombs. This term was kept for high explosive shells in rifled artillery of calibers of 122 mm and higher. In the beginning of the 1930’s the term “bomb” was dropped from artillery terminology.
(2) Aerial bombs, one of the types of aviation ammunition.
(3) A projectile for destroying submarines underwater.
What does it mean when you dream about a bomb?
A bomb is quite an attention-getter if it goes off in a dream. Perhaps a situation is becoming too explosive and the dreamer needs to tread carefully to avoid “land mines.” Alternatively, perhaps the dreamer is so tightly wound because of some situation that he or she feels ready to explode.
abend(ABnormal END) Pronounced "ab-end." An abend is an unexpected termination that causes the computer, smartphone or tablet to stop responding. The abend occurs either when the processor is presented with instructions or data it cannot recognize, or a program tries to address memory beyond a defined boundary. Abends are generally the result of erroneous software logic in the application or operating system (see anomaly).
Crash, Freeze, Lock Up and Hang
A "crash" occurs when the computer issues a "fault" and deliberately halts that line of execution. The terms "freeze," "lock up" or "hang" may refer to software that is actually still running but has erroneously wound up in an endless, internal loop that renders the program useless. In practice, the terms "crash," "freeze," "lock up" and "hang" are used synonymously. See infinite loop.
Bad Hardware Can Look Like Bad Software
A serious hardware failure will stop a computer-based device that has no redundant components. For example, a short circuit on the motherboard will halt the operation; however, a failing memory cell can cause an instruction to point to an erroneous location, making it look like a software failure.
It Depends on the OS
If the abend occurs due to a bug in an application and the operating system is not resilient, the computer locks up and has to be rebooted. Modern operating systems attempt to halt only the offending application and allow the remaining applications to continue. As operating systems evolve through the years, they are more tolerant of application bugs. However, operating systems themselves are not 100% foolproof, and bad applications can cause operating systems to crash; a major motivation for running in a virtual mode (see virtualization and virtual machine).
A Miracle It All Works
If you consider what goes on inside a computer, you might wonder why it does not crash more often. An ordinary home computer can easily have 64 billion memory (RAM) cells. Every second, millions of them switch their status between charged and uncharged (1 to 0; 0 to 1). If only one cell fails, it can cause an instruction to be invalid, and an abend can occur. See head crash, GPF, active area and transistor concept.
|The green blocks are machine instructions executed by the CPU one after the other until a branch (jump) instruction breaks the sequence and points to an instruction elsewhere in the program. Abending (crashing, hanging, etc.) occurs when the program erroneously points outside of its address space, typically due to bad logic.|