Tuesday, September 18, 2007

Access Tip (Shortcut keys)
EVERYONE LOVES A SHORTCUT
Since everyone likes shortcut keys, here's a collection for Access.

ACTION KEYS TO PRESS

Display Control menu Alt+Spacebar
Open Replace dialog box Ctrl+H
Open new database Ctrl+N
Open existing database Ctrl+O
Paste the Clipboard contents at the cursor Ctrl+V
Copy to the Clipboard Ctrl+C
Cut to the Clipboard Ctrl+X
Undo Ctrl+Z
Open Find Ctrl+F

PowerPoint Tip Pictures in a presentation

Steps to bring pictures into Power Point.

1. Get a picture file from the net or a camera, save it to disk, andremember its location. (You can save pictures that you see in netscapeby right clicking the pictures and selecting "Save Image As..")
2. Go to the slide in your presentation that you wish the picture to bein.
3. In Power Point click Insert -> Picture -> From File...
4. A dialog box will come up called "Insert Picture"
5. You must use the "Look in:" drop box to select the drive/dir thatyour file is in. Then select the image that you saved to disk earlierand click the "Insert" button.
The picture should now be in your Power Point slide.
Steps to add a special effect to the picture.
1. Right click the picture and select "Custom Animation..."
2. In the "Entry animation and sound" section you can select theanimation that you would like your picture to perform. Chose one thenclick the Timing tab.
3. Make sure that your picture is still selected in the "Animationorder" box.
4. The most common setting for Timing is to have the Animate andAutomatically selected in the "Start animation" section.
5. select how many seconds delay you want, click OK, and it should beready to go.

Excel Tip Using hyperlinks to link to next sheet

Although we've often discussed how to use hyperlinks in Word and PowerPoint documents, we haven't discussed hyperlinks in Excel worksheets.
Let's say you're working with a large workbook--one that contains multiple sheets. When you go through the workbook, you may want to make your way to the final sum on the first worksheet and then go to the next worksheet. In this case, why not use a hyperlink to take you to the next sheet?
Click the cell that contains that last sum and choose Insert, Hyperlink. When the Insert Hyperlink dialog box opens, click the Bookmark button. Select Sheet2 (under the Cell Reference title) and click OK. Back in the Insert Hyperlink dialog box, click OK to close the dialog box and save your selection. All you have to do now is click the last sum cell to move to the next sheet.
Suppose that now you'd like to go from that last sum cell to a specific cell in Sheet2. To do this, you'll have to name the target cell in Sheet2. Go to Sheet2 and click the target cell. Choose Insert, Name, Define. When the Define Name dialog box opens, type in a name and click OK.
Now, go back to that last sum cell in Sheet1. Click the cell and choose Insert, Hyperlink. When the Insert Hyperlink dialog box opens, click the Bookmark button. Now, in the Select Place in Document dialog box, you will see your target cell's name (under the Defined Names title). Select it and click OK. Click OK back in Insert Hyperlink to close the dialog box and save your changes.
When you click the hyperlink now, Excel will take you directly to the target cell in Sheet2.

Tuesday, August 21, 2007

*Memory Allocation*
In computer science, dynamic memory allocation is the allocation of memory storage for use in a computer program during the runtime of that program. It is a way of distributing ownership of limited memory resources among many pieces of data and code. Importantly, the amount of memory allocated is determined by the program at the time of allocation and need not be known in advance. A dynamic allocation exists until it is explicitly released, either by the programmer or by a garbage collector; this is notably different from automatic and static memory allocation, which require advance knowledge of the required amount of memory and have a fixed duration. It is said that an object so allocated has dynamic lifetime.
  • Memory Segmentation - is one of the most common ways to achieve memory protection; another common one is paging. Segmentation means that a part or parts of the memory will be sealed off from the currently running process, through the use of hardware registers. If the data that is about to be read or written to is outside the permitted address space of that process, a segmentation fault will result.

    Segmentation is a memory-management scheme that supports this user view of memory. A logical address space is actually a collection of segments. Each segment has a name and a length. The address specifies both the segment name and the offset within the segment. The user therefore specifies each address by 2 parameters: a segment name and an offset.

  • Input/Output Ports - Input and output to any endpoint is handled using the same mechanism known as a port, which allows the same procedures to be used for reading, writing, and other operations, regardless of where the data is coming from or going to. You can create ports that connect to disk files, memory buffers, internet sites, multicast networks, or serial ports, just to name a few.

    In Isis, a port is represented as a list of several items, which includes the port type, internal identity information, and the procedures used to operate on the port. It will usually not be necessary to look at anything in this list, and of course, nothing in the list should ever be modified manually. Use only the port manipulation routines described below.

  • Internal Register - allocated a module address which is programmed into the processor units bus interface.
*Interrupt Vectors*
An interrupt vector is the memory address of an interrupt handler, or an index into an array called an interrupt vector table or dispatch table. Interrupt vector tables contain the memory addresses of interrupt handlers. When an interrupt is generated, the processor saves its execution state via a context switch, and begins execution of the interrupt handler at the interrupt vector.
  • Bois - refers to the firmware code run by an IBM compatible PC when first powered on. The primary function of the BIOS is to prepare the machine so other software programs stored on various media (such as hard drives, floppies, and CDs) can load, execute, and assume control of the PC[3]. This process is known as booting up.

    BIOS can also be said to be a coded program embedded on a chip that recognizes and controls various devices that make up the PC. The term BIOS is specific to personal computer vendors. Among other classes of computers, the generic terms boot monitor, boot loader or boot ROM are commonly used. Boot is short for bootstrapping.

  • Dos - is an operating system commercialized by Microsoft. It was the most commonly used member of the DOS family of operating systems and was the dominant operating system for the PC compatible platform during the 1980s. It has gradually been replaced on consumer desktop computers by various generations of the Windows operating system.

    MS-DOS was originally released in 1981 and had eight major versions released before Microsoft stopped development in 2000. It was the key product in Microsoft's growth from a programming languages company to a diverse software development firm, providing the company with essential revenue and marketing resources.

*Instruction Sets*
Is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O. An ISA includes a specification of the set of opcodes (machine language), the native commands implemented by a particular CPU design.
  • Data Transfer Instructions - When stored in memory the bytes, words, and doublewords in the packed data types are stored in consecutive addresses, with the least significant byte, word, or doubleword being stored in the lowest address and the more significant bytes, words, or doubleword being stored at consecutively higher addresses. The ordering of bytes, words, or doublewords in memory is always little endian: the bytes with the lower addresses are less significant than the bytes with the higher addresses.
  • Branch Instruction - A branch (or jump on some computer architectures, such as the PDP-8 and Intel x86) is a point in a computer program where the flow of control is altered. The term branch is usually used when referring to a program written in machine code or assembly language; in a high-level programming language, branches usually take the form of conditional statements, subroutine calls or GOTO statements. An instruction that causes a branch, a branch instruction, can be taken or not taken: if a branch is not taken, the flow of control is unchanged and the next instruction to be executed is the instruction immediately following the current instruction in memory; if taken, the next instruction to be executed is an instruction at some other place in memory. There are two usual forms of branch instruction: a conditional branch that can be either taken or not taken, depending on a condition such as a CPU flag, and an unconditional branch which is always taken.
  1. Conditional Jumps - instruction will examine the flags, and if the flags are in the correct state (the condition is true), execution will be transferred to some label that you specify. If the flags are not in the correct state (the condition is false), then no action is taken, and execution continues with the next instruction in sequence.
  2. Unconditional Jumps - The relative branch commands calculate the address of the next instruction adding an instruction's parameter (called bias) to current value of program counter. So processor skips several instructions or returns over several ones.
*Looping Instructions*
Are provided for a Single Instruction. Multiple Data (SIMD) execution engine. For example, when a first loop instruction is received at an execution engine information in an n-bit loop mask register may be copied to an n-bit wide, m-entry deep loop stack.


*Arithmetic Instructions*
The MMX technology supports both saturating and wraparound modes. In wraparound mode, results that overflow or underflow are truncated and only the lower (least significant) bits of the result are returned. In saturation mode, results of an operation that overflow or underflow are clipped (saturated) to a data-range limit for the data type. The result of an operation that exceeds the range of a data type saturates to the maximum value of the range, while a result that is less than the range of a data type saturates to the minimum value of the range.