Quotes from Charles Petzold

Many MIDI files contain entire musical compositions. Because MIDI supports only 16 channels, however, no more than 16 different instruments can play at any time, and one of those is the key-based percussion instrument.

I started out with machine code and assembly language.

A MIDI file contains coded instructions to play a particular series of notes on an electronic music synthesizer. A MIDI file is more like a piano roll in a player piano than any type of sound recording.

I really liked figuring things out on my own. Early on in the development of a new version of Windows, I would explore it, I would try out various things, I would see what worked, I would see what didn't work.

I felt more like a scientist exploring nature, and Windows was my environment. You don't pass judgment on nature; you just explain how it works.

MIDI made a natural transition to the PC. The MIDI messages that make up a musical composition can be saved as MIDI files, which are collections of MIDI messages with timing information.

All modern MIDI synthesizers are capable of polyphony, which means they can play more than one note at a time and more than one instrument at a time.

Code is not like other how-computers-work books. It doesn't have big color illustrations of disk drives with arrows showing how the data sweeps into the computer. Code has no drawings of trains carrying a cargo of zeros and ones. Metaphors and similes are wonderful literary devices but they do nothing but obscure the beauty of technology.

Programming in machine code is like eating with a toothpick.

We could just as reasonably base our number system on eight (if we were cartoon characters) or four (if we were lobsters) or even two (if we were dolphins).

To a programmer, an operating system is defined by its API.

Some people believe that Moore's Law will continue to be accurate until about 2015.

The flip side of this is that any information that can be reduced to a choice among two or more possibilities can be expressed using bits. Needless

That rare person who has 1,073,741,824 bytes of memory will say, "I've got a gig (and I'm not talking music).

The method you use is something called the base two logarithm. The logarithm is the opposite of the power. We know that 2 to the 7th power equals 128. The base two logarithm of 128 equals 7.

Few fantasies tickle the human pleasure center more than a vision of relaxing in a hammock watching some newfangled contraption we just built mow the lawn.

I said early on in this chapter that we would need 144 relays for our adding machine. Here's how I figured that out: Each

Today's computers use transistors. When used in computers, transistors basically function the same way relays do, but (as we'll see) they're much faster and much smaller and much quieter and use much less power and are much cheaper. Building an 8-Bit Adder still requires 144 transistors (more if you replace the ripple carry with a look-ahead carry), but the circuit is microscopic.

We don't carry in subtraction, however; we borrow, and that involves an intrinsically different mechanism—a messy back-and-forth kind of thing.

Bits also play a part in logic, that strange blend of philosophy and mathematics for which a primary goal is to determine whether certain statements are true or false. True

Xamarin.Forms allows you to be as platform-independent or as platform-specific as you need to be. Xamarin.Forms doesn't replace Xamarin.iOS and Xamarin.Android; rather it integrates with them.

This equivalence wasn't discovered until the 1930s, most notably by Claude Elwood Shannon (born 1916), whose famous 1938 M.I.T. master's thesis was entitled "A Symbolic Analysis of Relay and Switching Circuits.

Thus, 1 is actually a function with the two bound variables f and x. Just offhand, those two variables seem like two more variables than are needed to define a simple number.

In the same way that Morse code reduces written language to dots and dashes, the spoken version of the code reduces speech to just two vowel sounds. The key word here is two. Two types of blinks, two vowel sounds, two different anything, really, can with suitable combinations convey all types of information.