8279 Keyboard/Display Interface Microprocessor and Interfacing by Ravinder Nath Rajotiya - April 5, 2020April 25, 20220 Keyboard Types Mechanical key switches Membrane type: with advantage that they can be made very thin and sealed Capacitive Type: When a key is pressed the capacitance between the plates varies. Hall effect: No mechanical contact. It take advantage of the deflection of a moving charge by a magnetic field. Keyboard Circuit connection and Interfacing Detect a key press De-bounce the key press Encode the valid key to produce a standard code for pressed key The above three tasks can be performed with hardware, software or a combination depending on the application Keyboard interfacing Figure show the interfacing of the keypad using 8255. The rows of the keypad are connected to say PORT-A and columns connected to PORT-B. PA is in
Experiment-4-Factorial of a number in 8086 8086 Programming by Ravinder Nath Rajotiya - April 19, 2019April 29, 20220 AIM: Write a Program to generate Factorial of a number Objective: To understand the concept of multiplication using direct MUL instruction in 8086. To understand how to use 16-bit results To analyze the process and the result System Requirement : 8086 Trainer Kit with Key Board Setting up the Trainer Kit: Ensure that standard IBM PC/AT system keyboard is connected System is Powered ON Student has a handy opcode table for programming Use data Address as : For Program Code segment address : 1000 Offset address : 0200 For Data segment address : 0000 Offset address : 1300 Result : from offset 130A Flowchart: Algorithm to find the factorial of a number– Input the Number whose factorial is to be find and