$390,000 Promissory Note - Storage Technology Corp. and Michael McLay


US$390,000                                                          May 10, 2001

                                 PROMISSORY NOTE
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For value received, Michael McLay ("Executive"), residing at 359 Primrose Place,
Burlington Ontario L7N 1T7, Canada, promises to pay to the order of Storage
Technology Corporation ("StorageTek"), the principal sum of Three Hundred Ninety
Thousand United States Dollars (US$390,000.00), when due in accordance with the
terms of this Promissory Note, in immediately available funds, at One StorageTek
Drive, Louisville, Colorado 80028, USA, or at such other office within the
United States as StorageTek may designate.

This Promissory Note shall be subject in all respects to the following terms and
conditions:

1. Term.  Unless earlier due in accordance with the terms hereof, all amounts
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owing under this Promissory Note shall be due and payable in full on May 10,
2004, the third anniversary of Executive's date of hire (May 10, 2001).

2. Interest.  Interest shall accrue at the rate of 4.63% per annum on the
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outstanding principal amount of this Promissory Note. The accrued interest shall
be due and payable annually, in full, on each anniversary date of the loan as
described in paragraph 1 above, commencing on May 10, 2002.

3. Repayment.  If during the term of this Promissory Note, (a) the Executive's
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employment with StorageTek is terminated by means of a voluntary resignation by
the Executive or by StorageTek for "cause", as said term is defined in the May
10, 2001, letter agreement entered into by the parties hereto (the "Letter
Agreement"), or (b) the Executive sells or transfers the property located at 359
Primrose Place, Burlington, Ontario L7N 1T7, Canada, the Executive agrees to
repay immediately upon the effective date of said termination, sale or transfer,
the entire principal amount and accrued interest due on this Promissory Note. If
during the term of this Promissory Note the Executive's employment with
StorageTek is terminated by StorageTek other than for "cause", as said term is
defined in the Letter Agreement, Executive agrees to repay within ninety (90
days) of the effective date of said termination, the entire principal amount and
accrued interest due on this Promissory Note.

4. Prepayment.  Executive may prepay this Promissory Note, in whole or in part,
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from time-to-time, without penalty.

5. Notices.  All notices and communications required or permitted under this
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Promissory Note must be in writing and delivered by hand, fax, courier or first
class mail.

6. Attorney's Fees.  If any action at law or in equity is necessary to enforce
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or interpret the terms of this Promissory Note, the prevailing party shall be
entitled to reasonable attorney's fees and costs, in addition to any other
relief to which such party may be entitled.

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7. Absolute Obligation.  No provision of this Promissory Note shall alter or
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impair the obligation of the Executive, which obligation is absolute and
unconditional, to pay the amount of this Promissory Note at the time, place and
in the manner herein described.

8. Governing Law.  This Promissory Note shall be governed by and construed in
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accordance with the laws of the State of Colorado, USA, excluding its conflict
of laws provisions. Any action against the undersigned concerning this
Promissory Note and the indebtedness evidenced hereby may be brought in any
court of competent jurisdiction. The Executive hereby acknowledges the
jurisdiction of any such courts and waives, to the fullest extent permitted by
law, the defense of an inconvenient forum to the maintenance of such action.

9. Secured Note.  This Promissory Note is secured by the property located at
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359 Primrose Place, Burlington, Ontario L7N 1T7, Canada, pursuant to a mortgage
dated as of the date hereof.

THE EXECUTIVE UNDERSTANDS THAT THIS IS A FULL RECOURSE PROMISSORY NOTE AND THAT
THE HOLDER OF THIS PROMISSORY NOTE MAY, AT ITS OPTION, PROCEED AGAINST ASSETS OF
THE EXECUTIVE IN THE EVENT OF A DEFAULT. THE EXECUTIVE HEREBY WAIVES PRESENTMENT
OR DEMAND FOR PAYMENT, DISHONOR OR OTHER FORMALITY. THIS PROMISSORY NOTE IS DUE
AND PAYABLE WITHOUT SET-OFF OR DEDUCTION OF ANY KIND.

This Promissory Note constitutes the entire agreement with respect to this
subject matter, supercedes all previous discussions and agreements, and is
signed and delivered as of May 10, 2001.

                                                   MICHAEL MCLAY



                                                   -------------------------

Agreed and Accepted
Storage Technology Corporation


By
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Title
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