I believe Volume 4 Chapter 3 The NOT Gate s/b "This circuit is composed exclusively of resistors, diodes and bipolar transistors." instead of

"This circuit is composed exclusively of resistors and bipolar transistors."

Good site...

Marty

 

http://www.allaboutcircuits.com/vol_4/chpt_3/2.html

Shown here is a schematic diagram for a real inverter circuit, complete with all necessary components for efficient and reliable operation:

This circuit is composed exclusively of resistors and bipolar transistors. Bear in mind that other circuit designs are capable of performing the NOT gate function, including designs substituting field-effect transistors for bipolar (discussed later in this chapter).

Good call.

This is a TTL gate. A RTL gate would be a bit different. A TTL gate can be built without diodes, but since the author chose to use this schematic it is a false claim. D1 isn't really needed, and R4, Q3, D2, and Q4 is a classic TTL totem pole output, fairly standard on most TTL gates.