Reads are made by direct calls (not buffered), but if dynamic values are being read and an actual write is taking place the reads are temporarily blocked.

If bit 2 of 'type' is set on entry then the command is passed on to the limits tests - see Limits.txt

In general it returns a float representing the wanted element.

If bit 7 of 'type' set is returned this should be regarded as an integer.

If bit 6 set is returned then the control is MIDI-learnable.
