Write data to a specific memory address on the C64 using hex string (PUT method)
AI agents use ultimate_write_memory to create or update resources in Commodore 64 Ultimate MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Commodore 64 Ultimate MCP Server environment.
This tool directly writes data to memory addresses on the C64 hardware. While technically a 'Write' operation, it carries high severity because arbitrary memory writes on a running system can corrupt program state, crash the system, or overwrite critical memory regions. However, it is generally reversible (memory can be overwritten again), so it falls under Write rather than Destructive.
From the tool's definition Write data to a specific memory address on the C64 using hex string (PUT method)
Documented attack patterns abuse exactly the kind of access ultimate_write_memory gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Commodore 64 Ultimate MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for ultimate_write_memory:
{
"version": "1",
"default": "deny",
"tools": {
"ultimate_write_memory": {
"limits": [
{
"counter": "ultimate_write_memory_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}ultimate_write_memory stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Write data to a specific memory address on the C64 using hex string (PUT method). It is categorised as a Write tool in the Commodore 64 Ultimate MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Commodore 64 Ultimate MCP Server MCP server in PolicyLayer and add a rule for ultimate_write_memory: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Commodore 64 Ultimate MCP Server. Nothing to install.
ultimate_write_memory is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the ultimate_write_memory rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for ultimate_write_memory. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
ultimate_write_memory is provided by the Commodore 64 Ultimate MCP Server MCP server (martijn-devrev/ultimate64mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Commodore 64 Ultimate MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
39 Commodore 64 Ultimate MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.