This design, with feature elements only present if the feature is unemulated or imperfect, doesn't account for feature relevance: both machines that don't support, for example, a mouse and machines that use a well emulated mouse don't mention the mouse feature.
Currently, machines that support a mouse cannot be reliably distinguished: some have a reference to certain devices such as "a2mouse" or "mouse_systems_mouse" containing a control type="mouse" element, but many machines (e.g. various Amiga models) directly have control type="mouse" inputs; many others (e.g. "pv7") only have ports and dipswitches referring to the mouse; and it must be assumed that there are even less perspicuous other cases.
A feature name="mouse" element (without status or with a "good" status value) in a machine with a working mouse would therefore provide useful information at a very modest cost. Note that among the listed initial set of feature types, all are conceivably optional and suitable for being treated like peripheral-like features such as mouse.
|