X0202 4 2007-09-05 1 0000813347 KOMAG INC /DE/ KOMG 0001230580 YAMASHITA TSUTOMU T 1710 AUTOMATION PARKWAY SAN JOSE CA 95131 0 1 0 0 EVP, CTO Common Stock 2007-09-05 4 D 0 43117 32.25 D 0 D Employee Stock option (Right to buy) 18.85 2007-09-05 4 D 0 1693 13.40 D 2014-03-15 Common Stock 1693 0 D Employee Stock option (Right to buy) 32.10 2007-09-05 4 D 0 14717 0.15 D 2017-02-15 Common Stock 14717 0 D Of these shares, 3,333 were issued pursuant to a 10,000 share restricted stock agreement, which provided for vesting at the rate of 1/3rd of the shares on each of February 15, 2006, February 15, 2007 and February 15, 2008. Of these shares, 9,333 were issued pursuant to a 14,000 share restricted stock agreement, which provided for vesting at the rate of 1/3rd of the shares on each of February 15, 2007, February 15, 2008 and February 15, 2009. Of these shares, 25,000 were issued pursuant to a 25,000 share restricted stock agreement, which provided for vesting at the rate of 1/3rd of the shares on each of October 3, 2007, October 3, 2008 and October 3, 2009. Of these shares, 5,451 were issued pursuant to a 5,451 share restricted stock agreement, which provided for vesting at the rate of 1/3rd of the shares on each of February 15, 2008, February 15, 2009 and February 15, 2010. Continuation of footnote (1). All 43,117 of such shares were canceled in the merger of State M Corporation, a wholly-owned subsidiary of Western Digital Corporation (the "Parent"), with and into the Issuer (the "Merger"), in exchange for a right to receive cash in the aggregate amount of $1,390,523.25 (or $32.25 per share); provided, however, that the receipt of cash will remain subject to the vesting provisions set forth in the restricted stock agreements and Parent is only obligated to pay cash to the extent the right vests during continued employment. This option, originally for 6,250 shares and which provided for vesting at the rate of 1/4th of the shares on 03/15/05 and as to 1/36th of the remaining shares on the 15th of each month thereafter, was canceled in the Merger in exchange for a right to receive cash in the aggregate amount of $22,686.20, less any applicable withholding taxes, representing the difference between the exercise price of the option and the $32.25 per share offer price (the "Offer Price") in the Merger; provided, however, that the receipt of cash will remain subject to the vesting provisions set forth in the option and Parent is only obligated to pay cash to the extent the right vests during continued employment. This option, which provided for vesting at the rate of 4,906 shares on 02/15/08 and as to 1/24th of the remaining shares on the 15th of each month thereafter, was canceled in the Merger in exchange for a right to receive cash in the aggregate amount of $2,207.55, less any applicable withholding taxes, representing the difference between the exercise price of the option and the Offer Price; provided, however, that the receipt of cash will remain subject to the vesting provisions set forth in the option and Parent is only obligated to pay cash to the extent the right vests during continued employment. /s/ Jan Schwartz, Attorney-in-fact for Tsutomu Yamashita 2007-09-05