Abstract: A write-data signal compensastion apparatus for disk storage including a number of write signal compensation circuits having different compensation amounts. Write signal compensation is achieved by the disk storage itself using one of the compensation circuit. A compensation amount selecting device is provided for designating whether write signal compensation should be performed or not, and in the case of compensation, the selecting device generates a selection signal designating the compensastion amount in response to the radial position of the data write head on a disk. A compensation amount switching circuit, receives the selection signal from the compensation amount selecting device and transmits the write signal to the disk storage. When the compensation amount designated by the selection signal is zero, the original write signal is transmitted without change; otherwise, the original signal is compensated by the amount designated by the compensation amount selecting device.