3 Wired hardware - MY 89s52 Burner

When I was in my college I was crazy for Embedded Electronics.Almost I use to spend all my week ends in making circuits and interfacing into PC.I love interfacing systems to my PC through serial and parallel port.
I still believe that the tool Visual basic 6.0 from MS was really helpful for me to get my interface done in a single night.My first successful interfacing was with a microcontroller,i believe it was in my 4th Sem.I was able to control l a stepper motor step angle dynamically from PC.Then I should talk about my burner for 89s52,it was having simple three wire interface with PC. Even it look simple the program has been complex to convert HEX to binary then doing serial transmission through DB25. Simple look at program:

uC89S52.cls: This class file consists of all the sub functions of the programmers like

· Switch on_off the microcontroller.

· Applying the high_low pulse

· Reading data through MISO

· Writing data through MOSI

Applying SCK pulse

Hexreader.cls:this file performs the following functions

• Fetch the hex file data in INTEL Hex format
• Decode thr file to get the hex data equivalent for the ALP program.
• Chck the hex code by using the check sum for each line
• Send the hex data to the frmmain to display in a spreadsheet