Legacy Circuit Mockups

Supported Components

Microprocessors & Memory

Logic & Timer ICs

Passive & Active Components

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

1. Define breadboard dimensions and grid
2. Place power rail connections (+5V and GND)
3. Add LED component with anode/cathode orientation
4. Place current-limiting resistor
5. Draw wire connections between components
6. Add labels and annotations

Creating a 555 Timer Circuit

1. Place NE555 IC on breadboard (pins 1-4 left, 5-8 right)
2. Connect pin 1 (GND) to ground rail
3. Connect pin 8 (Vcc) to power rail
4. Add timing resistors and capacitors
5. Wire trigger and threshold connections
6. Connect output to LED or other load

Creating a 6502 Microprocessor Layout

1. Place W65C02S centered on breadboard
2. Add 28C256 EEPROM for program storage
3. Place W65C22 VIA for I/O
4. Add 7400-series logic for address decoding
5. Wire address bus (A0-A15)
6. Wire data bus (D0-D7)
7. Connect control signals (R/W, PHI2, RESB)
8. Add reset button and clock crystal

Component Pinout Quick Reference

555 Timer (8-pin DIP)

W65C02S (40-pin DIP) - Key Pins

28C256 EEPROM (28-pin DIP) - Key Pins

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

LED Colors

Build Examples

Build 1 — Single LED

Components: Red LED, 220Ω resistor, jumper wires, power source

Steps:

1. Insert black jumper wire from power GND to row A5
2. Insert red jumper wire from power +5V to row J5
3. Place LED with cathode (short leg) in row aligned with GND
4. Place 220Ω resistor between power and LED anode

Build 2 — 555 Astable Blinker

Components: NE555, LED, resistors (10kΩ, 100kΩ), capacitor (10µF)

Steps:

1. Place 555 IC straddling center channel
2. Connect pin 1 to GND, pin 8 to +5V
3. Connect pin 4 to pin 8 (disable reset)
4. Wire 10kΩ between pin 7 and +5V
5. Wire 100kΩ between pins 6 and 7
6. Wire 10µF between pin 6 and GND
7. Connect pin 3 (output) to LED circuit

Troubleshooting

References

Detailed component specifications are available in the bundled reference files:

Documentation

• 555 — Complete 555 timer IC specification
• 6502 — MOS 6502 microprocessor details
• 6522 — W65C22 VIA interface adapter
• 28256-eeprom — AT28C256 EEPROM specification
• 6C62256 — 62256 SRAM details
• 7400-series — TTL logic gate pinouts
• assembly-compiler — Assembly compiler specification
• assembly-language — Assembly language specification
• basic-electronic-components — Resistors, capacitors, switches
• breadboard — Breadboard specifications
• common-breadboard-components — Comprehensive component reference
• connecting-electronic-components — Step-by-step build guides
• emulator-28256-eeprom — Emulating 28256-eeprom specification
• emulator-6502 — Emulating 6502 specification
• emulator-6522 — Emulating 6522 specification
• emulator-6C62256 — Emulating 6C62256 specification
• emulator-lcd — Emulating a LCD specification
• lcd — LCD display interfacing
• minipro — EEPROM programmer usage
• t48eeprom-programmer — T48 programmer reference

Examples

• Circuit Build Examples — Example circuit layouts and component configurations

Scripts

• Circuit Component Registry — Component registry for circuit mockups

Cross-Client Portability

This skill is written to stay usable across GitHub Copilot, Claude Code, Codex, and Gemini CLI.

• GitHub Copilot: keep the folder in a Copilot-visible skill or plugin path, or wrap the workflow as project instructions if the host does not support portable skill folders directly.
• Claude Code: keep the folder in a local skills directory or a compatible plugin or marketplace source.
• Codex: install or sync the folder into $CODEX_HOME/skills/<skill-name> and restart Codex after major changes.
• Gemini CLI: this repository generates a project command named /skills:legacy-circuit-mockups from this skill. Rebuild commands with python scripts/export-gemini-skill.py legacy-circuit-mockups and then run /commands reload inside Gemini CLI.

MCP Availability And Fallback

No dedicated MCP server is required for the normal workflow in this skill.

• If the current host lacks an equivalent tool surface, use the bundled scripts, standard shell or editor tooling, and the manual workflow already described in this skill.
• Treat local verification as the fallback evidence path before closing the task.

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