Exhibit 10.1.2


                  FIRST AMENDMENT TO SECURITY AGREEMENT

THIS FIRST AMENDMENT TO SECURITY AGREEMENT (this "Amendment"), dated as
of August 16, 1999, is made between HMT TECHNOLOGY CORPORATION, a
Delaware corporation (the "Borrower") and CREDIT SUISSE FIRST BOSTON and
FLEET NATIONAL BANK, as agents for the Banks party to the Credit
Agreement referenced below (in such capacity, the "Agents").
The Borrower, the Banks and the Agents are parties to a Revolving Credit
Agreement dated as of November 2, 1998. The Borrower's obligations under
the Revolving Credit Agreement are secured by certain Collateral, as
more specifically described in that certain Security Agreement dated as
of November 2, 1998, between the Borrower and the Agents (the "Security
Agreement").

The Borrower, the Banks and the Agents have agreed to
certain amendments to the above-referenced Revolving Credit Agreement,
as more specifically set forth in that certain First Amendment to
Revolving Credit Agreement of even date herewith (the "First Amendment")
(the Revolving Credit Agreement, as amended by the First Amendment, the
"Credit Agreement").

In connection with the First Amendment, the Borrower has requested that
the Agents agree to certain amendments to the Security Agreement to,
among other things, release the Agents' security interest in certain
Collateral.  The Agents have agreed to such request, subject to the
terms and conditions hereof.

Accordingly, the parties hereto agree as follows:

Definitions; Interpretation.

Terms Defined in Security Agreement.  All capitalized terms used in this
Amendment and not otherwise defined herein shall have the meanings
assigned to them in the Security Agreement.

Interpretation.  The rules of interpretation set forth in Section 1.2 of
the Credit Agreement shall be applicable to this Amendment and are
incorporated herein by this reference.

Partial Release of Collateral.  Effective on the date of the
satisfaction of the conditions precedent set forth in Section 4 below
(the "Effective Date"), the Agents hereby release their security
interest in the following types or items of Collateral, whether now
existing or hereafter acquired or arising: all Accounts, all Documents,
all Equipment, all Inventory and, except as provided in the immediately
succeeding sentence, all Books.  The Borrower agrees and acknowledges
that the Agents do not hereby release, and the Agents expressly retain,
their security interests and Liens upon all Collateral, whether now
existing or hereafter acquired or arising, consisting of Deposit
Accounts, Instruments, Investment Property, Chattel Paper, Books
relating to Deposit Accounts, Instruments, Investment Property or
Chattel Paper, products and Proceeds of any and all of the foregoing and
Letter of Credit Proceeds.

Reaffirmation of Liens.  Except as expressly amended or released hereby,
the Borrower hereby reaffirms that the Liens granted to the Agents for
the benefit of the Banks under the Security Agreement and the other
Collateral Documents constitute valid and perfected first priority Liens
on the Collateral (subject only to Permitted Liens) securing the
Borrower's Obligations under the Credit Agreement and the other Loan
Documents.

Other Amendments to the Security Agreement.

Amendments.  The Security Agreement shall be amended as follows,
effective as of the Effective Date:

Section 4 of the Security Agreement is hereby amended by deleting
subsections (g), (h) and (i).

(ii)    Section 5 of the Security Agreement is hereby amended
by deleting subsections (l), (m), (p) and (q).

Section 6 of the Security Agreement is hereby amended by deleting
subsection (a).

(iv)    Section 7 of the Security Agreement is hereby amended
and restated as follows:

            "SECTION 7      Authorization; Agents Appointed
             Attorney-in-Fact.  The Agents shall have the right to, in the name
             of the Borrower, or in the name of the Agents or otherwise,
             without notice to or assent by the Borrower, and the Borrower
             hereby constitutes and appoints the Agents (and any of each
             Agent's officers or employees or agents designated by either
             Agent) as the Borrower's true and lawful attorney-in-fact, with
             full power and authority to:

                          (1) sign any of the Financing
             Statements which must be executed or filed to perfect or continue
             perfected, maintain the priority of or provide notice of the
             Agents' security interest in the Collateral;

                          (2) take possession of and endorse
             any notes, acceptances, checks, drafts, money orders or other
             forms of payment or security in order to collect any Proceeds of
             any Collateral;

                          (3) exercise dominion and control
             over, and refuse to permit further withdrawals from, Deposit
             Accounts maintained with the Agents, any Bank or any other bank,
             financial institution or other Person;

                          (4) enforce payment or any other
             rights in respect of any Collateral, grant consents, agree to any
             amendments, modifications or waivers of the agreements and
             documents governing any Collateral, and otherwise file any claims,
             take any action or institute, defend, settle or adjust any
             actions, suits or proceedings with respect to any Collateral, as
             the Agents may deem necessary or desirable to maintain, preserve
             and protect the Collateral, to collect the Collateral or to
             enforce the rights of the Agents with respect to the Collateral;

                          (5) execute any and all
             endorsements, assignments or other documents and instruments
             necessary to sell, lease, assign, convey or otherwise transfer
             title in or dispose of the Collateral;

                          (6) execute and deliver to any
             securities intermediary or other Person any entitlement order,
             Account Control Agreement or other notice, document or instrument
             which the Agents may deem necessary of advisable to maintain,
             protect, realize upon and preserve the Investment Property and the
             Agents' security interest therein; and

                          (7) execute any and all such other
             documents and instruments, and do any and all acts and things for
             and on behalf of the Borrower, which the Agents may deem necessary
             or advisable to maintain, protect, realize upon and preserve the
             Collateral and the Agents' security interest therein and to
             accomplish the purposes of this Agreement.

                    The Agents agree that, except upon the occurrence and
             during the continuance of an Event of Default, it shall not
             exercise the power of attorney, or any rights granted to the
             Agents, pursuant to clauses (2) through (7).  Subject to the
             immediately preceding sentence with respect to the periods during
             which the foregoing power of attorney may be exercised, the
             foregoing power of attorney is coupled with an interest and
             irrevocable so long as the Banks have any Commitments or the
             Secured Obligations have not been paid and performed in full.  The
             Borrower hereby ratifies, to the extent permitted by law, all that
             the Agents shall lawfully and in good faith do or cause to be done
             by virtue of and in compliance with this Section 7."

(v)     Section 10 of the Security Agreement is hereby amended
by deleting the text "or, in the case of Equipment, render it
nonfunctional," from the third line.

(vi)    Section 22 of the Security Agreement is hereby amended
by deleting the text "earlier of (i) the release of the security
interest granted hereby pursuant to Section 28 of the Credit Agreement,
or (ii) the" from the first and second lines.

References Within Security Agreement.  Each reference in the Security
Agreement to "this Agreement" and the words "hereof," "herein,"
"hereunder," or words of like import, shall mean and be a reference to
the Security Agreement as amended by this Amendment.

Conditions of Effectiveness.  The effectiveness of this
Amendment shall be subject to the satisfaction of each of the following
conditions precedent:

Executed Counterpart.  The Agents shall have received from the Borrower
a duly executed counterpart of this Amendment.

First Amendment to Revolving Credit Agreement.  All conditions precedent
to the effectiveness of the First Amendment shall have been satisfied.
Representations and Warranties; No Default.  On the Effective Date,
after giving effect to the amendment of the Security Agreement
contemplated hereby:

the representations and warranties contained in Section 5 below shall be
true and correct on and as of the Effective Date as though made on and
as of such date; and

no Default shall have occurred and be continuing.

Additional Documents.  The Agent shall have received, in form and
substance satisfactory to it, such additional approvals, documents and
other information as the Agents or any Bank (through the Agents) may
reasonably request.

Representations and Warranties.  To induce the Agents to
enter into this Amendment, the Borrower hereby confirms and restates, as
of the date hereof, the representations and warranties made by it in
Section 4 of the Security Agreement, after giving effect to the
amendments set forth in Section 2 above.  For the purposes of this
Section 5, (i) each reference in Section 4 of the Security Agreement to
"this Agreement," and the words "hereof," "herein," "hereunder," or
words of like import in such Section, shall mean and be a reference to
the Security Agreement as amended by this Amendment, and each reference
in such Section to "the Loan Documents" shall mean and be a reference to
the Loan Documents as amended as contemplated hereby and (ii)  any
representations and warranties which relate solely to an earlier date
shall not be deemed confirmed and restated as of the date hereof
(provided that such representations and warranties shall be true,
correct and complete as of such earlier date).

Miscellaneous.

Notice.  The Agents shall notify the Borrower and the Banks of the
occurrence of the Effective Date.

Security Agreement Otherwise Not Affected.  Except as expressly amended
pursuant hereto, the Security Agreement shall remain unchanged and in
full force and effect and is hereby ratified and confirmed in all
respects.  The Banks' and the Agents' execution and delivery of, or
acceptance of, this Amendment and any other documents and instruments in
connection herewith (collectively, the "Amendment Documents") shall not
be deemed to create a course of dealing or otherwise create any express
or implied duty by any of them to provide any other or further
amendments, consents or waivers in the future.

No Reliance.  The Borrower hereby acknowledges and confirms to the
Agents and the Banks that the Borrower is executing this Amendment and
the other Amendment Documents on the basis of its own investigation and
for its own reasons without reliance upon any agreement, representation,
understanding or communication by or on behalf of any other Person.
Costs and Expenses.  The Borrower agrees to pay to the Agents on demand
the reasonable out-of-pocket costs and expenses of the Agents, and the
reasonable fees and disbursements of counsel to the Agents, in
connection with the negotiation, preparation, execution and delivery of
this Amendment and any other documents to be delivered in connection
herewith.

Binding Effect.  This Amendment shall be binding upon, inure to the
benefit of and be enforceable by the Borrower, the Agents and each Bank
and their respective successors and assigns.
Governing Law.  THIS AMENDMENT SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAW OF THE STATE OF CALIFORNIA.

Complete Agreement; Amendments.  This Amendment, together with the other
Amendment Documents and the other Loan Documents, contains the entire
and exclusive agreement of the parties hereto and thereto with reference
to the matters discussed herein and therein.  This Amendment supersedes
all prior commitments, drafts, communications, discussion and
understandings, oral or written, with respect thereto.  This Amendment
may not be modified, amended or otherwise altered except in accordance
with the terms of Section 25 of the Credit Agreement.

Severability. Whenever possible, each provision of this Amendment shall
be interpreted in such manner as to be effective and valid under all
applicable laws and regulations.  If, however, any provision of this
Amendment shall be prohibited by or invalid under any such law or
regulation in any jurisdiction, it shall, as to such jurisdiction, be
deemed modified to conform to the minimum requirements of such law or
regulation, or, if for any reason it is not deemed so modified, it shall
be ineffective and invalid only to the extent of such prohibition or
invalidity without affecting the remaining provisions of this Amendment,
or the validity or effectiveness of such provision in any other
jurisdiction.

Counterparts.  This Amendment may be executed in any number of
counterparts and by different parties hereto in separate counterparts,
each of which when so executed shall be deemed to be an original and all
of which taken together shall constitute but one and the same agreement.
Interpretation.  This Amendment and the other Amendment Documents are
the result of negotiations between and have been reviewed by counsel to
the Agents, the Borrower and other parties, and are the product of all
parties hereto.  Accordingly, this Amendment and the other Amendment
Documents shall not be construed against any of the Banks or the Agents
merely because of the Agents' or any Bank's involvement in the
preparation thereof.

Loan Documents. This Amendment and the other Amendment Documents shall
constitute Loan Documents.

                           [Signature page follows.]

IN WITNESS WHEREOF, the parties hereto have duly executed this
Amendment, as of the date first above written.

                          THE BORROWER

                          HMT TECHNOLOGY CORPORATION

                          By
                                  Name:
                                  Title:

                          THE AGENTS

                          CREDIT SUISSE FIRST BOSTON,
                          as Agent

                          By
                                  Name:
                                  Title:

                          By
                                  Name:
                                  Title:

                          FLEET NATIONAL BANK, as Agent

                          By
                                  Name:
                                  Title: