Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add PracticalSwan/agent-skills --skill legacy-circuit-mockupsgit clone --depth 1 https://github.com/PracticalSwan/agent-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/practicalswan/agent-skills/legacy-circuit-mockups)<a href="https://agentmods.dev/skills/practicalswan/agent-skills/legacy-circuit-mockups"><img src="https://agentmods.dev/badge/skills/practicalswan/agent-skills/legacy-circuit-mockups/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/practicalswan/agent-skills/legacy-circuit-mockups"><img src="https://agentmods.dev/badge/skills/practicalswan/agent-skills/legacy-circuit-mockups.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high Prompt Injection · line 308 Hidden instructions were detected in comments or invisible text. These could contain malicious directives. Manual review is recommended.Fix: Audit all comments and invisible characters. Remove any instructions that direct the agent to perform unauthorized actions. Use plain, reviewable content.
- medium analysis-evasion · line 1 Suspicious Unicode normalization or mixed-script contentFix: Review the flagged content for security risks. Ensure no credentials, secrets, or sensitive data are exposed.
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00048 | $0.03207 |
| Opus 5 | $0.00024 | $0.01604 |
| Sonnet 5 | $0.00010 | $0.00641 |
| Haiku 4.5 | $0.00005 | $0.00321 |
Grade A, and why
legacy-circuit-mockups scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 338 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Legacy Circuit Mockups
A skill for creating breadboard circuit mockups and visual diagrams for retro computing and electronics projects. This skill leverages HTML5 Canvas drawing mechanisms to render interactive circuit layouts featuring vintage components like the 6502 microprocessor, 555 timer ICs, EEPROMs, and 7400-series logic gates.
- Leverage native parallel subagent dispatch and 200k+ context windows where available.
When to Use This Skill
Use symptom -> action triggers: when one matches, apply this skill and verify with the protocol below.
- User asks to create a breadboard layout or circuit mockup
- User wants visualized component placement for legacy electronics
- User needs diagrams for 6502, 555 timer, EEPROM, VIA, or 7400-series builds
- User asks for educational electronics visuals or wiring diagrams
- User is following retro-computing tutorials and needs visual references
Prerequisites
- Understanding of component pinouts from bundled reference files
- Knowledge of breadboard layout conventions (rows, columns, power rails)
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 |
What ships with it
24 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- CHANGELOG.md 6.6 KB
- examples/circuit-build-examples.md 6.5 KB
- LICENSE.txt 1.0 KB
- references/28256-eeprom.md 4.6 KB
- references/555.md 32 KB
- references/6502.md 5.7 KB
- references/6522.md 5.7 KB
- references/6C62256.md 4.1 KB
- references/7400-series.md 4.6 KB
- references/assembly-compiler.md 4.7 KB
- references/assembly-language.md 5.2 KB
- references/basic-electronic-components.md 2.7 KB
- references/breadboard.md 4.9 KB
- references/common-breadboard-components.md 6.4 KB
- references/connecting-electronic-components.md 15 KB
- references/emulator-28256-eeprom.md 5.1 KB
- references/emulator-6502.md 5.7 KB
- references/emulator-6522.md 6.5 KB
- references/emulator-6C62256.md 4.8 KB
- references/emulator-lcd.md 5.0 KB
- references/lcd.md 5.2 KB
- references/minipro.md 4.0 KB
- references/t48eeprom-programmer.md 4.3 KB
- scripts/circuit-component-registry.js 4.8 KB runs code
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 4d ago Changed a2b5c487ce25
- 6d ago Changed 70fb3015153b
- 8d ago First seen · 338 lines · 48 tokens per session scan A a50c94325a5c
legacy-circuit-mockups is a skill published in the GitHub repository PracticalSwan/agent-skills (14 stars, last pushed 4d ago), licensed MIT. It adds 48 tokens to every session and 3,207 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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