Contenido

1. Introduction
2. History: how light learned to count people
3. Lesson 0. Gates from transistors: for those who start from scratch
   1. 0.1. The idea: a transistor is a switch
   2. 0.2. Building
   3. 0.3. Check
   4. Lesson 0 paste (Cmd+I)
4. Lesson 1. The beam and CD4011
   1. 1.1. Idea: how a shop counts people
   2. 1.2. Idea: the CMOS 4000 series
   3. 1.3. Idea: NAND for everything
   4. 1.4. Build
   5. 1.5. Check
   6. Lesson 1 paste (Cmd+I)
5. Lesson 2. The F/F flip-flop
   1. 2.1. Idea: a counter is flip-flops that flip
   2. 2.2. Idea: flipping through exclusive OR
   3. 2.3. Idea: a NAND with three inputs
   4. 2.4. Build
   5. 2.5. Check
   6. Lesson 2 paste (Cmd+I)
6. Lesson 3. The CD4029B counter
   1. 3.1. Idea: which bit to flip
   2. 3.2. Idea: controlling the counter
   3. 3.3. Idea: the bubbles on the TI drawing
   4. 3.4. Build
   5. 3.5. Check
   6. Lesson 3 paste (Cmd+I)
7. Lesson 4. The CD4511B decoder
   1. 4.1. Idea: seven strokes
   2. 4.2. Idea: latch, blanking, lamp test
   3. 4.3. Idea: a switch on two transistors
   4. 4.4. Build
   5. 4.5. Check
   6. Lesson 4 paste (Cmd+I)
8. Lesson 5. Direction
   1. 5.1. Idea: two beams one after another
   2. 5.2. Idea: remember the first
   3. 5.3. Idea: the clock is when both are blocked
   4. 5.4. Build
   5. 5.5. Check
   6. Lesson 5 paste (Cmd+I)
9. Lesson 6. The visitor counter
   1. 6.1. Idea: two displays on the same beams
   2. 6.2. Idea: two digits — two counters
   3. 6.3. Idea: Reset holds
   4. 6.4. Build
   5. 6.5. Check
   6. Lesson 6 paste (Cmd+I)
10. Summary
11. All the parts
12. Instructions in pictures