
<PAGE>

                             HEARTSTREAM, INC.

            SPECIAL MEETING OF STOCKHOLDERS - MARCH __, 1998
        THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS
                 OF HEARTSTREAM, INC. (THE "COMPANY")

     The undersigned hereby appoints Alan J. Levy and James R. Shay, and each 
of them, as attorneys-in-fact and proxies of the undersigned, with full power 
of substitution, to vote all of the shares of the Company's common stock 
which the undersigned may be entitled to vote at the Special Meeting of 
Stockholders of the Company to be held at The Edgewater, 2411 Alaskan Way, 
Seattle, Washington 98121, on March __, 1998 at 9:00 a.m., local time, 
and at any and all adjournments or postponements thereof, with all of the 
powers the undersigned would possess if personally present, upon and in 
respect of the following proposal and in accordance with the following 
instructions. The proposal referred to herein is described in detail in the 
accompanying Proxy Statement/Prospectus.

     UNLESS A CONTRARY DIRECTION IS INDICATED, THIS PROXY WILL BE VOTED FOR 
THE PROPOSAL SPECIFIED ON THE REVERSE SIDE. IF A SPECIFIC DIRECTION IS 
INDICATED, THIS PROXY WILL BE VOTED IN ACCORDANCE THEREWITH.

             (CONTINUED AND TO BE SIGNED ON REVERSE SIDE)


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                                                               PLEASE
                                                             MARK VOTES   /X/
                                                             AS IN THIS
                                                               EXAMPLE

PLEASE MARK, DATE, SIGN AND RETURN THIS PROXY CARD PROMPTLY IN THE ENCLOSED 
POSTPAID RETURN ENVELOPE. THE BOARD OF DIRECTORS RECOMMENDS A VOTE FOR THE 
FOLLOWING PROPOSAL.

<TABLE>
<S>                                                                                 <C>      <C>        <C>
1. To (i) approve and adopt the Agreement and Plan of Reorganization, dated          FOR     AGAINST    ABSTAIN
   as of December 29, 1997, among the Company, Hewlett-Packard Company, a            / /       / /        / /
   California corporation ("HP"), and Whistler Acquisition Corporation, a 
   Delaware corporation and wholly-owned subsidiary of HP, and (ii) approve the 
   merger of Whistler Acquisition Corporation with and into the Company pursuant 
   to which the Company will become a wholly-owned subsidiary of HP and all 
   outstanding shares of the Company's Common Stock will be converted into 
   shares of HP Common Stock

   The undersigned acknowledges receipt of a copy of the Notice of Special 
   Meeting of Stockholders and Proxy Statement/Prospectus relating to the 
   meeting.

                                                                   IMPORTANT: In signing this proxy please sign 
                                                                   exactly as your name(s) is (are) shown on the share 
                                                                   certificate to which the proxy applies. When signing 
                                                                   as an attorney, executor, administrator, trustee or 
                                                                   guardian, please give your full title as such. If a 
                                                                   corporation, please sign in full corporate name by 
                                                                   President or other authorized officer. If a 
                                                                   partnership, please sign in partnership name by 
                                                                   authorized person. EACH JOINT TENANT OR COMMUNITY 
                                                                   PROPERTY HOLDER OF THE SHARES MUST SIGN.

                                                                   PLEASE MARK, SIGN, DATE AND RETURN THIS PROXY CARD 
                                                                   PROMPTLY USING THE ENCLOSED ENVELOPE.


SIGNATURE(s)_______________________________________________________________  DATE__________________________________
(Additional signature if held jointly)_____________________________________
</TABLE>


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