Plug-and-Play cards that employ the above implementation, but do not have at least one of the above devices, will be reflected as an unknown device detected under the configuration manager (eg Windows 95). For example, Sound Blaster 16 PNP model CT2959 does not have a wave table device i.e. E-mu chip, and so will have one unknown device detected by the PNP Configuration Manager. Another example: Sound Blaster 16 PNP model CT2943 which does not have an IDE CDROM interface or E-mu chipset will have two unknown devices detected.
This, however, does not affect the system performance or use up any additional system resources. Users are advised to ignore the message if such a symptom occurs.