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Diagnostics module

What it does

Diagnostics runs measurements that are too costly, invasive, or specialized for idle collection. Each diagnostic must state its cost before execution.

The macOS Diagnostics module

Availability

PowerPC has the full page. NOW-68K exposes selected diagnostics such as VRAM and screenshot-source probes through the console rather than a matching page.

On the modern Mac

The host selects a named machine and records the request, status, and returned evidence. It must not turn a timeout into a measurement.

On the classic Mac

The PowerPC page states cost and progress. The 68K console's vprobe and shotdiag commands use the same bounded diagnostic implementations as wire calls.

The PowerPC Diagnostics page

Common tasks

  • Read the cost and required rig before running a diagnostic.
  • Save the resulting build, machine, port, and artifact identity with numbers.

Some diagnostics allocate scarce classic memory, read the display, or hold a transfer lane. Do not run them during unrelated machine use.

Failure states

Not armed, unsafe on this machine, unavailable manager, timed out, partial, and result-buffer limit are different outcomes.

Current limitations

An instrument that wrote no artifact cannot support an absence claim. A count not derived from the stored result is not evidence.

For developers

See emulator and metal workflow and emulator readiness.