SKILL.md
$2c
Supported Components
Microprocessors & Memory
Component
Pins
Description
W65C02S
40-pin DIP
8-bit microprocessor with 16-bit address bus
28C256
28-pin DIP
32KB parallel EEPROM
W65C22
40-pin DIP
Versatile Interface Adapter (VIA)
62256
28-pin DIP
32KB static RAM
Logic & Timer ICs
Component
Pins
Description
NE555
8-pin DIP
Timer IC for timing and oscillation
7400
14-pin DIP
Quad 2-input NAND gate
7402
14-pin DIP
Quad 2-input NOR gate
7404
14-pin DIP
Hex inverter (NOT gate)
7408
14-pin DIP
Quad 2-input AND gate
7432
14-pin DIP
Quad 2-input OR gate
Passive & Active Components
Component
Description
LED
Light emitting diode (various colors)
Resistor
Current limiting (configurable values)
Capacitor
Filtering and timing (ceramic/electrolytic)
Crystal
Clock oscillator
Switch
Toggle switch (latching)
Button
Momentary push button
Potentiometer
Variable resistor
Photoresistor
Light-dependent resistor
Grid System
// Standard breadboard grid: 20px spacing
const gridSize = 20;
const cellX = Math.floor(x / gridSize) * gridSize;
const cellY = Math.floor(y / gridSize) * gridSize;Component Rendering Pattern
// All components follow this structure:
{
type: 'component-type',
x: gridX,
y: gridY,
width: componentWidth,
height: componentHeight,
rotation: 0, // 0, 90, 180, 270
properties: { /* component-specific data */ }
}Wire Connections
// Wire connection format:
{
start: { x: startX, y: startY },
end: { x: endX, y: endY },
color: '#ff0000' // Wire color coding
}Step-by-Step Workflows
Creating a Basic LED Circuit Mockup
- Define breadboard dimensions and grid
- Place power rail connections (+5V and GND)
- Add LED component with anode/cathode orientation
- Place current-limiting resistor
- Draw wire connections between components
- Add labels and annotations
Creating a 555 Timer Circuit
- Place NE555 IC on breadboard (pins 1-4 left, 5-8 right)
- Connect pin 1 (GND) to ground rail
- Connect pin 8 (Vcc) to power rail
- Add timing resistors and capacitors
- Wire trigger and threshold connections
- Connect output to LED or other load
Creating a 6502 Microprocessor Layout
- Place W65C02S centered on breadboard
- Add 28C256 EEPROM for program storage
- Place W65C22 VIA for I/O
- Add 7400-series logic for address decoding
- Wire address bus (A0-A15)
- Wire data bus (D0-D7)
- Connect control signals (R/W, PHI2, RESB)
- Add reset button and clock crystal
Component Pinout Quick Reference
555 Timer (8-pin DIP)
Pin
Name
Function
1
GND
Ground (0V)
2
TRIG
Trigger (< 1/3 Vcc starts timing)
3
OUT
Output (source/sink 200mA)
4
RESET
Active-low reset
5
CTRL
Control voltage (bypass with 10nF)
6
THR
Threshold (> 2/3 Vcc resets)
7
DIS
Discharge (open collector)
8
Vcc
Supply (+4.5V to +16V)
W65C02S (40-pin DIP) - Key Pins
Pin
Name
Function
8
VDD
Power supply
21
VSS
Ground
37
PHI2
System clock input
40
RESB
Active-low reset
34
RWB
Read/Write signal
9-25
A0-A15
Address bus
26-33
D0-D7
Data bus
28C256 EEPROM (28-pin DIP) - Key Pins
Pin
Name
Function
14
GND
Ground
28
VCC
Power supply
20
CE
Chip enable (active-low)
22
OE
Output enable (active-low)
27
WE
Write enable (active-low)
1-10, 21-26
A0-A14
Address inputs
11-19
I/O0-I/O7
Data bus
Formulas Reference
Resistor Calculations
- Ohm's Law: V = I × R
- LED Current: R = (Vcc - Vled) / Iled
- Power: P = V × I = I² × R
555 Timer Formulas
Astable Mode:
- Frequency: f = 1.44 / ((R1 + 2×R2) × C)
- High time: t₁ = 0.693 × (R1 + R2) × C
- Low time: t₂ = 0.693 × R2 × C
- Duty cycle: D = (R1 + R2) / (R1 + 2×R2) × 100%
Monostable Mode:
- Pulse width: T = 1.1 × R × C
Capacitor Calculations
- Capacitive reactance: Xc = 1 / (2πfC)
- Energy stored: E = ½ × C × V²
Color Coding Conventions
Wire Colors
Color
Purpose
Red
+5V / Power
Black
Ground
Yellow
Clock / Timing
Blue
Address bus
Green
Data bus
Orange
Control signals
White
General purpose
LED Colors
Color
Forward Voltage
Red
1.8V - 2.2V
Green
2.0V - 2.2V
Yellow
2.0V - 2.2V
Blue
3.0V - 3.5V
White
3.0V - 3.5V
Build Examples
Build 1 — Single LED
Components: Red LED, 220Ω resistor, jumper wires, power source
Steps:
- Insert black jumper wire from power GND to row A5
- Insert red jumper wire from power +5V to row J5
- Place LED with cathode (short leg) in row aligned with GND
- Place 220Ω resistor between power and LED anode
Build 2 — 555 Astable Blinker
Components: NE555, LED, resistors (10kΩ, 100kΩ), capacitor (10µF)
Steps:
- Place 555 IC straddling center channel
- Connect pin 1 to GND, pin 8 to +5V
- Connect pin 4 to pin 8 (disable reset)
- Wire 10kΩ between pin 7 and +5V
- Wire 100kΩ between pins 6 and 7
- Wire 10µF between pin 6 and GND
- Connect pin 3 (output) to LED circuit
Troubleshooting
Issue
Solution
LED doesn't light
Check polarity (anode to +, cathode to -)
Circuit doesn't power
Verify power rail connections
IC not working
Check VCC and GND pin connections
555 not oscillating
Verify threshold/trigger capacitor wiring
Microprocessor stuck
Check RESB is HIGH after reset pulse
References
Detailed component specifications are available in the bundled reference files:
- 555.md - Complete 555 timer IC specification
- 6502.md - MOS 6502 microprocessor details
- 6522.md - W65C22 VIA interface adapter
- 28256-eeprom.md - AT28C256 EEPROM specification
- 6C62256.md - 62256 SRAM details
- 7400-series.md - TTL logic gate pinouts
- assembly-compiler.md - Assembly compiler specification
- assembly-language.md - Assembly language specification
- basic-electronic-components.md - Resistors, capacitors, switches
- breadboard.md - Breadboard specifications
- common-breadboard-components.md - Comprehensive component reference
- connecting-electronic-components.md - Step-by-step build guides
- emulator-28256-eeprom.md - Emulating 28256-eeprom specification
- emulator-6502.md - Emulating 6502 specification
- emulator-6522.md - Emulating 6522 specification
- emulator-6C62256.md - Emulating 6C62256 specification
- emulator-lcd.md - Emulating a LCD specification
- lcd.md - LCD display interfacing
- minipro.md - EEPROM programmer usage
- t48eeprom-programmer.md - T48 programmer reference