A remote-control and debugging tool for the Habitat C64 client running on Ultimate 64 hardware. Ultimate 64 is a modern hardware recreation of the Commodore 64 computer.

Use it to pause and resume the C64, inspect or disassemble 6502 processor memory, read and write bytes, upload a cartridge file, or boot Habitat from disks.

It lets developers inspect a paused machine and diagnose crashes without working only through the client interface. It can also change memory and start software on the device.

How ssalevan/habiclient configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to ssalevan/habiclient. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/ssalevan/habiclient/main/.claude/skills/u64/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/ssalevan/habiclient

Made for: Claude Code.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/ssalevan/habiclient/u64/github.svg)](https://agentmods.dev/skills/ssalevan/habiclient/u64)

Your own site

<a href="https://agentmods.dev/skills/ssalevan/habiclient/u64"><img src="https://agentmods.dev/badge/skills/ssalevan/habiclient/u64/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/ssalevan/habiclient/u64"><img src="https://agentmods.dev/badge/skills/ssalevan/habiclient/u64.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,867 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

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	$0.00000	$0.01867
Opus 5.5	$0.00000	$0.00747
Sonnet 5.5	$0.00000	$0.00373
Haiku 4.5	$0.00000	$0.00187

Measured 2mo ago against content hash e28128613e4c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

u64 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 2mo 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.

.claude/skills/u64/SKILL.md · 183 lines

How it starts

The opening of the file, as written. The whole thing — 183 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ultimate 64 Remote Debugging

Remote control and debug the Habitat C64 client running on Ultimate 64 hardware via REST API.

Usage

Use u64_tool.py in the project root to automate the U64. Write and run Python scripts that import U64Session.

Quick crash diagnosis

from u64_tool import U64Session

u = U64Session("192.168.1.158")
u.diagnose()
# CPU paused, key memory locations dumped
# Call u.resume() when done

Memory inspection

from u64_tool import U64Session

u = U64Session("192.168.1.158")
u.pause()
u.dump(0x0800, 0x40)           # Hex+ASCII dump
u.disassemble(0x080D, 32)      # 6502 disassembly
val = u.read_byte(0x0001)      # Read single byte
word = u.read_word(0xFFFA)     # Read 16-bit LE word
data = u.read_mem(0x0100, 256) # Read raw bytes
u.resume()

Memory writes

u.write_byte(0xD020, 0x02)             # Set border color
u.write_bytes(0xFFFA, [0xFC, 0x01])    # Set NMI vector

Upload and boot CRT

u = U64Session("192.168.1.158")
u.upload_crt("Dist/Habitat.crt")
# U64 resets and boots from cartridge

Full Habitat boot (disk-based)

u = U64Session("192.168.1.158")
u.boot_habitat("steve")
# Mounts disks, resets, navigates launcher, waits for game

Screen reading

u.pause()
rows = u.read_screen()       # All 25 rows as ASCII
row5 = u.read_screen(5)      # Single row
u.dump_screen()              # Print all rows
u.wait_for_screen_text("HABITAT", timeout=30)  # Poll until text appears
u.resume()

Keystroke injection

u.inject_keys(0x0D)             # Press Return
u.type_text("steve")            # Type name + Return (auto-appended)

CLI Usage

python3 u64_tool.py 192.168.1.158 --diagnose        # Full crash diagnostics
python3 u64_tool.py 192.168.1.158 --boot-state       # Quick boot check
python3 u64_tool.py 192.168.1.158 --pause             # Pause CPU
python3 u64_tool.py 192.168.1.158 --resume            # Resume CPU
python3 u64_tool.py 192.168.1.158 --reset             # Reset C64
python3 u64_tool.py 192.168.1.158 --dump 0800 40      # Dump memory (hex)
python3 u64_tool.py 192.168.1.158 --disasm 080D 20    # Disassemble (hex)
python3 u64_tool.py 192.168.1.158 --read 0001         # Read byte
python3 u64_tool.py 192.168.1.158 --write D020 02     # Write byte
python3 u64_tool.py 192.168.1.158 --screen            # Dump screen text
python3 u64_tool.py 192.168.1.158 --crt Dist/Habitat.crt   # Upload CRT
python3 u64_tool.py 192.168.1.158 --boot steve        # Full boot sequence
python3 u64_tool.py 192.168.1.158 --check             # Check game state
python3 u64_tool.py 192.168.1.158 --version           # Firmware version

Read the full file on GitHub · 183 lines

Changes

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.

2mo ago First seen · 183 lines · 0 tokens per session scan A e28128613e4c

Subscribe to this mod's changes

u64 is a skill published in the GitHub repository ssalevan/habiclient (12 stars, last pushed 3mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,867 tokens. 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 2026-08-30.

Debugging Hardware and IoT

u64 next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
u64ssalevan/habiclient	Skill	12	3mo ago	MIT	A	0	Claude Code
gke-ai-troubleshooting-tpu-dynamic-slices-monitoringgoogle/skills	Skill	24k	yesterday	Apache-2.0	A	107	Claude Code, Codex
gke-ai-troubleshooting-tpu-vbar-oomgoogle/skills	Skill	24k	yesterday	Apache-2.0	A	125	Claude Code, Codex
doca-flowNVIDIA/skills	Skill	3.9k	yesterday	Apache-2.0	A	224	Claude Code, Codex
competition-firmware-layoutzhaoxuya520/reverse-skill	Skill	44k	1mo ago	MIT	A	110	Codex
diagnose-driver-installNVIDIA/deepops	Skill	1.5k	2d ago	BSD-3-Clause	A	47	Claude Code, Codex
catc-troubleshootautomateyournetwork/netclaw	Skill	717	yesterday	Apache-2.0	A	114	Claude Code

habiclient: Skill for Claude Code