Most portable computers and personal digital assistants (PDA's) are compatible with the Nokia 6090 phone. To be physically connected to the Nokia 6090 phone a personal computer needs a serial port. Supported operated systems include Windows 95, 98 and NT operating systems. The connection cable is a standard serial cable also known as the DB-9 cable. Compatible personal digital assistants include the Windows CE and Palm OS based personal assistant with an RS232 connectivity cable in which one end must be male (available from your PDA manufacturer).

Certain car radios can be used to amplify the Nokia 6090 phone line-out audio signaling, in which case the car's radio loudspeakers and the volume control of the car radio are used, instead of the loudspeaker provided with the Nokia 6090 phone. To facilitate this, the car-radio should have a line-in connector for an external CD player or similar device. Such a connector may be located at the back of the car radio or in its front panel.