COM means the serial port, while LPT (not the LTP) means the parallel port. The serial port is a port provided by the computer bus for data transmission. In the serial port, data is transmitted in a bitwise stream, LPT is another
most spp parallel ports, the control bits are in open collector/open drain mode, that is, they can also be used as input. To read the external logic signal from the control bit, first write the corresponding output to "1", and then read the value of the control register. However, in order to increase the switching speed, most of the ports supporting the EPP and ECP modes work in the push-pull mode where th
(UInt16 i)//Delay Function{UCHAR8 J; for(; i>0; i--) for(j=0;j the; j + +) ;} Main () {SCON=0x00; EA=1;//Total interrupt allowedes=1;//allow serial total interruptsNsendbyte=1;//light data initialized to 0000 0001 fed into nsendbyteSbuf=nsendbyte;//write to Sbuf buffer to light data, start serial sendp1_0=0; while(1) { ; }}voidSerial_port () Interrupt4 using 0 { if(T1)//If the t1=1;1 byte is sent in a serial{p1_0=1;//that is 0x90=1;??? allow 74ls164 chip
Parallel port for short, it has 3 ports: Data port, State port, control port, commonly used and port is LPT1, its 3 ports address are: 378H, 379H and 37AH respectively.
First, the same mouth read and write
In assembly language,
C # Only the class for direct serial port operation is provided. If you operate the parallel port directly, you need to call the API function:
Using system. runtime. interopservices;
String senddata = "^ XA ^ fo50, 80 ^ ADN, 36,20 ^ fdtrw eol2 ^ FS ^ xz"; // zebra printer Command Format
[Dllimport ("kernel32.dll")]
Private Static extern int createfile (
String
control whether the data ports are high or low, the regular high/low level conversion constitutes a pulse signal, which can be directly output to the steering gear if properly controlled.LPT parallel pin definition:
D0 ~ D7: data interface. The parallel port transmits one byte at a time. When the parallel
With the continuous development of single-chip microcomputer applications, there are more and more multi-chip systems composed of multiple single-chip microcomputer, and information exchange between multiple single-chip microcomputer is a whole. The work of a single-chip microcomputer is divided into multiple single-chip microcomputer. On the one hand, the performance of the system can be improved, and on the other hand, the hardware design of the system can be simplified.Asynchronous serial por
7 parallel port service (parallel port service -- int 17 h)
00 h-output characters to the printer
01 H-initialize the printer port
02 h-read printer status
(1) function 00 h
Function Description: output characters to the printer
Entry parameter: Ah = 00 h
Al = output chara
Boot up an error window to view the Event Viewer. Found a red fork record: The Parallel port driver service failed to start because of the following error: The service could not be started because the device that has been disabled or associated with it has not started. "Don't know how to solve, search a bit, fix." Chongwen as follows: Some people say that finding system services can turn this off, but I sus
Boot up an error window to view the Event Viewer. Found a red fork record: The Parallel port driver service failed to start because of the following error: The service could not be started because the device that has been disabled or associated with it has not started. "Don't know how to solve, search a bit, fix." Chongwen as follows: Some people say that finding system services can turn this off, but I sus
Debug windbg dual-host Kernel through the parallel port, windbgkernel
Preface:
Windows kernel mode debug is available in two ways:
1. windbg dual-host kernel debugging
2. traceview capture wpp log debugging
This section describes how to use the parallel port for windbg dual-host kernel debugging.
Preparation:
1.
An error was recently found in the Event Viewer: "Parallel Port driver service failed to start due to the following error",I searched the internet for a bit and found that many of the pages said the solution:Put the Hkey_local_machine\system\controlset001\services\parport, change "start=3" to "start=0" canI just follow this method to operate a bit, and then restart the computer, but the result is: The compu
The following is an example of Telnet to port 22
Station91:~/shell/telnet_port # pwd
/root/shell/telnet_port
Station91:~/shell/telnet_port # Cat Telnet_port.sh
#!/bin/bash
RM telnet_result.txt >/dev/null 2>1
Port_22=22
For I in $ (cat ip.list)
Do (telnet $i $PORT _22
>telnet_result.txt ) >/dev/null 2>1
#加 Let it execute in parallel, >>telnet_resul
C # parallel port thermal invoice printer print bitmap including chip writing,
The following is the code to be called:
Class LptControl {private string LptStr = "lpt1"; public LptControl (string l_LPT_Str) {LptStr = l_LPT_Str;} [StructLayout (LayoutKind. sequential)] private struct OVERLAPPED {int Internal; int InternalHigh; int Offset; int OffSetHigh; int hEvent;} // Call DLL. [DllImport ("kernel32.dll")
Monolithic microcomputer Internal structure analysis: In order to know how the delay program is working, we must first understand some of the symbols appearing in the delay program, starting from R1, R1 is called the work register. What is a work register? let's look for answers in real life. If a math problem: 123+567, let you answer the result is how much, you will immediately answer is 690, and then see the following topic: 123+567+562, to let you have to answer, it is not so easy? What are w
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