Contenido

1. Introduction
2. A bit of history
3. Lesson 1. The plotter and the panel
   1. 1.1. Idea: two axes — any point of the sheet
   2. 1.2. Idea: an arrow means steps from a clock
   3. 1.3. Idea: PEN UP/DOWN — one button, two positions
   4. 1.4. Idea: ERROR
   5. 1.5. Build
   6. 1.6. Check
   7. Lesson 1 paste (Cmd+I)
4. Lesson 2. The turret: four pens
   1. 2.1. Idea: changing the pen means turning
   2. 2.2. Idea: the motor is two flip-flops in a ring
   3. 2.3. Idea: a quarter turn = 6 steps
   4. 2.4. Idea: two two-bit counters
   5. 2.5. Idea: turn until they match
   6. 2.6. Idea: BUSY — the pen is up while turning
   7. 2.7. Idea: which pen to lower
   8. 2.8. Build
   9. 2.9. Check
   10. Lesson 2 paste (Cmd+I)
5. Lesson 3. The card in the slot: the computer draws
   1. 3.1. Idea: the card has three addresses
   2. 3.2. Idea: the decoder — «no bit differs»
   3. 3.3. Idea: writing to a register
   4. 3.4. Idea: reading $C091 — onto the same bus
   5. 3.5. Idea: who drives — the CD4019
   6. 3.6. Build
   7. 3.7. Check
   8. Lesson 3 paste (Cmd+I)
6. Lesson 4. A program with a menu: seven pictures
   1. 4.1. Idea: the whole program is three addresses
   2. 4.2. Idea: «home» by the limit switches (lines 900–940)
   3. 4.3. Idea: a straight line from steps (lines 1000–1090)
   4. 4.4. Idea: colour and waiting (lines 1300–1330)
   5. 4.5. Idea: a picture is a table in DATA (lines 1500–1570, 3000…)
   6. 4.6. How to run it
   7. 4.7. Check
   8. The whole PLOTTER program
7. Summary
8. All the parts
9. Instructions in pictures