PCM redirects here. For other uses, see PCM (disambiguation). Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amplitude of the analog signal is sampled regularly at uniform intervals, and each sample is quantized to the nearest value within a range of digital steps.
1 As well as MLA, APA papers are also double-spaced with 1-inch margins on each side. 2  APA guidelines recommend you to use readable and clear font, such as Times New Roman, 12 pt.  The main distinction of APA style is a ârunning headâ at the top of each page.
Basics of an APA Format Essay. 1  There should be uniform margins of at least one-inch at the top, bottom, left, and right sides of your essay. 2  Your paper should be double-spaced. 3  Every page of your essay should include a running head at the top left.  Every page should also include a page number in the top right corner. Your essay should also have a title page in APA format. This title page should include the title of your paper, your name and school affiliation.