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Parallel ports are easy to program and faster with the RS-232 interface(serial port). But the disadvantage is that they need a series of gears. Because of this reason the parallel ports are not included in the distance. Tell us the fundamental difference between the work of the parallel and serial port.

In the serial interface, there are two lines of data transmission and a line to receive. To send data to a serial port, there must be a little after the other with additional start-bit, stop bit and parity bit for detect errors.
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    In the part 2, we will learn about controlling program Printer Port and Card 8255 I/O Port by Assembly that can be changed to be language of computer by using Assembler program like SXA-51, Cross-16, Cross-32 that can program by Editor, and then keep in file name .ASM. When comply have finished, will get file .Hex. If we use micro controller like 8051, 8052, 8055, etc. We can take file .Hex to put at CPU by EMULATOR PROGRAM CPU, but I will recommend to use Debug in your PC by typing Debug at C:\> on Dos in order to be learning to use mnemonic code that consist of the main 3 parts like the followings,

1.      Operation Code consists of 2-4 alphabets such as MOV, SJMP, etc.

2.      Operand is operated; it will be the set of alphabets that notify operation that will be one set or 2 sets. If there will be 2, it will have comma (,) like A, #20H, etc.

3.      Comment is explanation the meaning of codes that will be preceded by semicolon (;).

The group of commands of mnemonic code, are divided into 4 main groups,

1.      Logic, such as AND,OR,XOR,NOT

2.      Mathematic  such as INC,DEC,ADD,SUBB,MUL,DIV

3.      Control to manage working

4.      Processing as Boolean

Programming to control Card I/O 8255 port in Debug

1. Type the word, Debug at C:\ then will get – on the below line.
      2. then, type a, that will get data.
      3. Type Code like this,

4. Press Enter 1 time, then type P or R, you will get for running program that continuously Enter, it will have result like this,

      From the method I mentioned is experiment to easily program, but writing for real using, you have to write Editor so that you can keep and edit in the next time.

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From the article of Assembly, I introduced controlling port of Card I/O 8255 that is card that extends parallel port. Many people might not try to do because there is no card. This article is another method that uses controlling I/O through Printer port getting and sending signal.

The command used to control I/O Printer Data Port
send signal out Printer Port, we use the form of command like this,

OUT Address data port, Value
Address data port of printer=0378
Value that will send to printer data port, the number that control 8 bit is 00-FF.

OUT DX,AL

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Pascal is the another language that can program to connect controlling out of computer‘s port, such as Serial Port, RS-232, Parallel Port, Printer Port. Generally, many languages will have function for sending value and reading value from port.

Although, there is no language, it can be programmed to directly connect along port. So, you have to use the function from DLL file for sending the function that send and read value from port of Pascal like the following, Read the rest of this entry »

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The fellow programmer that program to connect with computer’s port on Window by using Borland C++ Builder that use the method that I suggested in programming connect to port that is run on DOS. Also, present how to program by MS VC++ 6 for running on Window that is using function of dos.h file, but cannot be used, despite declare #include at the top of program.

First of all, I want to disclaim that I don’t use Borland C++ Builder in programming because I practice just MS VC++ 6 , but trying to search information in the internet , then I find the answer that we have to use in writing function to connect to I/O Port by helping of assembly. I reminded that I used the method of writing in Delphi that you will use it to write within your program or will write as function in binary file. It will be more convenient in using that has how to write like the following, Read the rest of this entry »

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C language is the one of good complier for interface program via Serial Port,Parallel Port,Card I/O 8255 with output devices.

Programming Microsoft Visual C++ 6 communicating Parallel Port

You can notice that the structure of function is like programming by VB because Dll File that is used in VB that is written from C. I will not mention the fundamental of communicating port. Read the rest of this entry »

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I have already mentioned the content about C, C++, connecting with PC Port. It’s not too hard. It’s hard at graphics that we write to put together with using, especially program ran on DOS. In this present, programming as Visual is populating because it can be GUI conveniently and not too hard. So, I try to use Microsoft Visual Basic 6 that is in Microsoft Visual Studio 6, for function and step of programming code for connecting port is not much because wizard program of MS VC++6, is created all for us.

In this program, we will use file conio.h that is include file for using function _outp() and _inp()

In this section, I will do as explanation with pictures (Visual Learning), controlling with messages and the arrange of number shown because if you write explanation as the last contexts, you will be hard to understand. Read the rest of this entry »

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As we know that VB can’t program to connect through Parallel Port directly. In the book, there will be explanation that we create DLL files that can write by using whatever language that has the function connecting to port. This website I have ever presented programming by C++, using Inp function for getting value along port and out is sending value out along port.

So now, we will introduce creating DLL file (Dynamic LInk LIbrary) by Borland Delphi, using Assembly programming to help for connecting through port by using the function of Assembly.

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We can’t program by using Visual Basic, then connecting through Parallel port directly. We have to create DLL (Dynamic LInk LIbrary) file in order to borrow function connecting I/O port of the other languages to use. We can program by using functions that can connect port. In this article, I will present programming by C++ first. For someone who likes to program by Borland Delphi, click here. Let’s begin program DII file by MS VC++6 by using function connect with Input and Output of port like this,

1. _Inp that is function that will read value from input port’s position that has the function like this,

_Inp = read value as byte, we will set function name in order to be use in VB- - - > inpVB

_Inpw = read value as word, we will set function name in order to be used in VB - - - > inpwVB

_Inpd = read value as double words, we will set function name in order to used in VB - - - > inpdwVB Read the rest of this entry »

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