I want to build an oscilloscope without using ElVIS in order to modify the code as i want to my application , the signals will be taken by NI-myDAQ
Have a look at this project here: http://cnx.org/contents/i5A3G_iv@3/Student-Scope-Using-NI-USB-Dat
Here's a project that uses the PC sound card as the DAQ instrument. https://decibel.ni.com/content/docs/DOC-4834
The main VI of the project needs help to find a file when you first open it. See the last comment on the project page for info.