https://www.tutorialspoint.com/computer_logical_organization/index.htm

http://www.electronicsengineering.nbcafe.in/

https://www.geeksforgeeks.org/digital-electronics-logic-design-tutorials/
https://www.dsprelated.com/

http://freecomputerbooks.com/

http://examradar.com/short-question-answer/microprocessor/

https://mawdoo3.com/
https://www.arduino.cc/
https://www.tutorialspoint.com/cprogramming/