Colom Newbie

Assembly

Ianguage of Assembly ( Assembler) [is] to represent one of the so much included in programming language is Low Level Ianguage and only storey above machine Ianguage.

Assembly have excess which cannot be replaced by other programming language.

like :

- Result of program have high speed level

- Size measure of small program

- Very easy to access System Computer.

Segment and Offset

Segment and Offset represent a number 16 beet ( presented in number of hexa) showing a certain address in computer memory. this offset is referred as also address relative. Besides address relative, there are also absolute address in the form of number 20 beet ( presented in number of hexa). This Absolute address can be calculated by multiplying segment by 10 hexa and enhanced with offset. Example :

segment : offset

0100 : 1234

Address relative : 02234.

Interrupt

Interrupt is request to microprocessor to do a comand. On the happening of request interupt, microprocessor will execute handler interrupt , that is a[n program serving to interupt. Every that handler interrupt have kept address in the form of array which consist of 4 byte ( 2 offset and 2 segment). This array is referred by vektor interupt . Vektor interupt this compiled pursuant to number interupt that is from hexa. Besides, recognized also term of service and of subservice, its intention is every that interrupt is divided to become some part having duty alone. But there is also interrupt which do not have service, the example:

int 29.

Register

Register is to represent some of memory of microprocessor owning speed very high. Earn also analogy that register represent personnel of microprocessor.

Register divided to become five big shares that is

1. Segment Register ( 16 beet)

Register to show address from a segment. Which including segment register .

- CS ( Code Segment)

Showing address of segment of program which is is active

- DS ( Data of Segment)

Showing address of segment of program data ( variable)

- SS ( Stack Segment)

Showing address of segment of used by stack is program .

- ES ( Extra Segment)

Representing reserve segment register

2. Pointer and Index of Register ( 16 beet) Register to show address from a[n offset.

Which including pointer register and index

- SP ( Stack Pointer)

Border On SS ( SS : SP )

- BP ( Base of Pointer)

border with SS ( SS : BP )

- DI ( Destination Index)

border on of ES ( ES : DI). Weared for the operation of string .

- SI( Source Index)

border on of DS ( DS : THE). Weared for the operation of string.

3. General Purpose Register ( 16 beet)

This Register can be used to various need, but owning special function. type of Register this have individuality, that is can be divided again become register 8 beet, high register , and low register .

Which including purpose general register :

- AX --> AH|AL ( Accumulator)

To handle operation of arithmatika .

- BX --> BH|BL ( Base) To show offset address .

- CX --> CH|CL ( Counter) For looping, to showing how many times looping happened .

- DX --> DH|DL ( Data) To accomodate the rest of the division of number 16 beet.

4. Index of Pointer Register ( 16 beet)

Only consisting of 1 register that is IP which is berpasangan with CS reguster ( CS : IP) to show instruction address hereinafter to execute.

0125. Flags Register ( 1 beet)

This Register function to show a condition ( yes or do not).

This Register only valuable 0 and 1.

Which including flags register .

- OF ( Overflow Flag) 1 if happened overflow .

- SF ( Sign Flag) 1 if used by number have sign .

- ZF ( Zero Flag) 1 if result of valuable operation 0 .

- CF ( Carry Flag) 1 if operation yield carry .

- PF ( Parity Flag) 1 if result of even number operation .

- DF ( Direction Flag) 1 if downhill process path process path at string .

- IF ( Interrupt Flag) 1 if process can interupt .

- TF ( Trap Flag) 1 if earning ditrace / debug .

- AF ( Auxiliary Flag) used at number operation of BCD .

- NT ( Nested Task) used to handle to interupt beruntun .

- IOPL ( I/O Protection Level ) used for the mode of proteksi ( 2 beet)