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                                                                   EXHIBIT 10.15

                             SUBORDINATION AGREEMENT

         This Agreement, dated as of July 5, 1999, is made by William R. Childs
(the "Subordinated Creditor"), for the benefit of Wells Fargo Business Credit,
Inc., a Minnesota corporation (the "Lender").

         Chaparral Network Storage, Inc., formerly known as Chaparral
Technologies, Inc., a Delaware corporation (the "Borrower"), is now or hereafter
may be indebted to the Lender on account of loans or the other extensions of
credit or financial accommodations from the Lender to the Borrower, or to any
other person under the guaranty or endorsement of the Borrower.

         The Subordinated Creditor has made or may make loans or grant other
financial accommodations to the Borrower.

         As a condition to making any loan or extension of credit to the
Borrower, the Lender has required that the Subordinated Creditor subordinate the
payment of the Subordinated Creditor's loans and other financial accommodations
to the payment of any and all indebtedness of the Borrower to the Lender.
Assisting the Borrower in obtaining credit accommodations from the Lender and
subordinating his interests pursuant to the terms of this Agreement are in the
Subordinated Creditor's best interest.

         ACCORDINGLY, in consideration of the loans and other financial
accommodations that have been made and may hereafter be made by the Lender for
the benefit of the Borrower, and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the Subordinated
Creditor hereby agrees as follows:

         1. Definitions. As used herein, the following terms have the meanings
set forth below:

          "Availability" has the meaning given in the Credit Agreement.

          "Borrower Default" means a Default or Event of Default as defined in
     any agreement or instrument evidencing, governing, or issued in connection
     with Lender Indebtedness, including, but not limited to, the Credit
     Agreement, or any default under or breach of any such agreement or
     instrument.

          "Cash Flow" means the Borrower's fiscal year-to-date Net Income plus
     depreciation and amortization, plus other non-cash items including (without
     limitation) any deferred interest, less the sum of (a) Current Maturities
     of Long Term Debt and (b) unfinanced Capital Expenditures. Capitalized
     terms used in this definition and not defined in this Agreement shall have
     the meaning given in the Credit Agreement.

          "Credit Agreement" means the Credit and Security Agreement dated as of
     July 5, 1999, by and between the Borrower and the Lender, as the same may
     hereafter be amended, supplemented or restated from time to time.


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          "Current Maturities of Long Term Debt" as of a given date means the
     amount of the Borrower's long-term debt and capitalized leases which became
     due during the fiscal year-to-date period ending on the designated date.

          "Lender Indebtedness" means each and every debt, liability and
     obligation of every type and description which the Borrower may now or at
     any time hereafter owe to the Lender, whether such debt, liability or
     obligation now exists or is hereafter created or incurred, and whether it
     is or may be direct or indirect, due or to become due, absolute or
     contingent, primary or secondary, liquidated or unliquidated, or joint,
     several or joint and several, all interest thereon, all renewals,
     extensions and modifications thereof and any notes issued in whole or
     partial substitution therefor.

          "Subordinated Indebtedness" means all obligations arising under the
     Subordinated Note and each and every other debt, liability and obligation
     of every type and description which the Borrower may now or at any time
     hereafter owe to the Subordinated Creditor, whether such debt, liability or
     obligation now exists or is hereafter created or incurred, and whether it
     is or may be direct or indirect, due or to become due, absolute or
     contingent, primary or secondary, liquidated or unliquidated, or joint,
     several or joint and several.

          "Subordinated Note" means, collectively, all of the following: the
     Borrower's Promissory Note, dated as of January 27, 1999, in the original
     principal amount of $50,000, the Borrower's Promissory Note, dated as of
     March 1, 1999, in the original principal amount of $400,000, the Borrower's
     Promissory Note, dated as of March 18, 1999, in the original principal
     amount of $200,000, the Borrower's Promissory Note, dated as of April 1,
     1999, in the original principal amount of $200,000, and the Borrower's
     Promissory Note, dated as of April 14, 1999, in the original principal
     amount of $200,000, each payable to the Subordinated Creditor, and any
     other Promissory Note issued in the future by the Borrower payable to the
     Subordinated Creditor, provided such Promissory Note contains the legend
     set forth in Exhibit A hereto, together with all renewals, extensions and
     modifications thereof and any note or notes issued in substitution
     therefor.

         2. Subordination. The payment of all of the Subordinated Indebtedness
is hereby expressly subordinated to the extent and in the manner hereinafter set
forth to the payment in full of the Lender Indebtedness; and regardless of any
priority otherwise available to the Subordinated Creditor by law or by
agreement, the Lender shall hold a first security interest in all collateral
securing payment of the Lender Indebtedness (the "Collateral"), and any security
interest claimed therein (including any proceeds thereof) by the Subordinated
Creditor shall be and remain fully subordinate for all purposes to the security
interest of the Lender therein for all purposes whatsoever.

         3. Principal Payments. Until all of the Lender Indebtedness has been
paid in full, the Subordinated Creditor shall not, without the Lender's prior
written consent, demand, receive or accept any principal payment, from the
Borrower in respect of the Subordinated Indebtedness, or exercise any right of
or permit any setoff in respect of the Subordinated Indebtedness, except that
the



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Subordinated Creditor may accept payments of principal under the Subordinated
Note within 30 days of the end of each fiscal quarter, so long as (a) no
Borrower Default has occurred and is continuing or will occur as a result of or
immediately following any such payment, (b) average Availability for the 90-day
period prior to such payment is greater than $200,000, (c) Availability after
such payment will be greater than $200,000, (d) the sum of such payment and all
prior payments to Subordinated Creditor and all of the Borrower's other
subordinated creditors during the fiscal year in which such payment is proposed
to be made will not exceed 70% of the Borrower's fiscal year-to-date Cash Flow,
and (e) the date of the proposed payment is on January 1, 2000 or thereafter.

         4. Interest Payments. Without the Lender's prior written consent, the
Subordinated Creditor shall not demand, receive or accept any interest payment
from the Borrower in respect of the Subordinated Indebtedness so long as any
Borrower Default exists or if a Borrower Default will occur as a result of or
immediately following such interest payment.

         5. Receipt of Prohibited Payments. If the Subordinated Creditor
receives any payment on the Subordinated Indebtedness that the Subordinated
Creditor is not entitled to receive under the provisions of this Agreement, the
Subordinated Creditor will hold the amount so received in trust for the Lender
and will forthwith turn over such payment to the Lender in the form received
(except for the endorsement of the Subordinated Creditor where necessary) for
application to then-existing Lender Indebtedness (whether or not due), in such
manner of application as the Lender may deem appropriate. If the Subordinated
Creditor exercises any right of setoff which the Subordinated Creditor is not
permitted to exercise under the provisions of this Agreement, the Subordinated
Creditor will promptly pay over to the Lender, in immediately available funds,
an amount equal to the amount of the claims or obligations offset. If the
Subordinated Creditor fails to make any endorsement required under this
Agreement, the Lender, or any of its officers or employees or agents on behalf
of the Lender, is hereby irrevocably appointed as the attorney-in-fact (which
appointment is coupled with an interest) for the Subordinated Creditor to make
such endorsement in the Subordinated Creditor's name.

         6. Action on Subordinated Debt. The Subordinated Creditor will not
commence any action or proceeding against the Borrower to recover all or any
part of the Subordinated Indebtedness, or join with any creditor (unless the
Lender shall so join) in bringing any proceeding against the Borrower under any
bankruptcy, reorganization, readjustment of debt, arrangement of debt
receivership, liquidation or insolvency law or statute of the federal or any
state government, or take possession of, sell, or dispose of any Collateral, or
exercise or enforce any right or remedy available to the Subordinated Creditor
with respect to any such Collateral, unless and until the Lender Indebtedness
has been paid in full.

         7. Action Concerning Collateral.

          (a) Notwithstanding any security interest now held or hereafter
     acquired by the Subordinated Creditor, the Lender may take possession of,
     sell, dispose of, and otherwise deal with all or any part of the
     Collateral, and may enforce any right or remedy available to it with
     respect to the Collateral, all without notice to or consent of the
     Subordinated Creditor except as specifically required by applicable law.

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          (b) In addition, and without limiting the generality of the foregoing,
     if a Borrower Default has occurred and is continuing and the Borrower
     intends to sell any Collateral to an unrelated third party outside the
     ordinary course of business, the Subordinated Creditor shall, upon the
     Lender's request, execute and deliver to such purchaser such instruments as
     may reasonably be necessary to terminate and release any security interest
     or lien the Subordinated Creditor has in the Collateral to be sold.

          (c) The Lender shall have no duty to preserve, protect, care for,
     insure, take possession of, collect, dispose of, or otherwise realize upon
     any of the Collateral, and in no event shall the Lender be deemed the
     Subordinated Creditor's agent with respect to the Collateral. All proceeds
     received by the Lender with respect to any Collateral may be applied,
     first, to pay or reimburse the Lender for all costs and expenses (including
     reasonable attorneys' fees) incurred by the Lender in connection with the
     collection of such proceeds, and, second, to any indebtedness secured by
     the Lender's security interest in that Collateral in any order that it may
     choose.

         8. Bankruptcy and Insolvency. In the event of any receivership,
insolvency, bankruptcy, assignment for the benefit of creditors, reorganization
or arrangement with creditors, whether or not pursuant to bankruptcy law, the
sale of all or substantially all of the assets of the Borrower, dissolution,
liquidation or any other marshaling of the assets or liabilities of the
Borrower, the Subordinated Creditor will file all claims, proofs of claim or
other instruments of similar character necessary to enforce the obligations of
the Borrower in respect of the Subordinated Indebtedness and will hold in trust
for the Lender and promptly pay over to the Lender in the form received (except
for the endorsement of the Subordinated Creditor where necessary) for
application to the then-existing Lender Indebtedness, any and all moneys,
dividends or other assets received in any such proceedings on account of the
Subordinated Indebtedness, unless and until the Lender Indebtedness has been
paid in full. If the Subordinated Creditor shall fail to take any such action,
the Lender, as attorney-in-fact for the Subordinated Creditor, may take such
action on the Subordinated Creditor's behalf. The Subordinated Creditor hereby
irrevocably appoints the Lender, or any of its officers or employees on behalf
of the Lender, as the attorney-in-fact for the Subordinated Creditor (which
appointment is coupled with an interest) with the power but not the duty to
demand, sue for, collect and receive any and all such moneys, dividends or other
assets and give acquittance therefor and to file any claim, proof of claim or
other instrument of similar character, to vote claims comprising Subordinated
Indebtedness to accept or reject any plan of partial or complete liquidation,
reorganization, arrangement, composition or extension and to take such other
action in the Lender's own name or in the name of the Subordinated Creditor as
the Lender may deem necessary or advisable for the enforcement of the agreements
contained herein; and the Subordinated Creditor will execute and deliver to the
Lender such other and further powers-of-attorney or instruments as the Lender
may request in order to accomplish the foregoing.

         9. Restrictive Legend; Transfer of Subordinated Indebtedness. The
Subordinated Creditor will cause the Subordinated Note and all other notes,
bonds, debentures or other instruments evidencing the Subordinated Indebtedness
or any part thereof to contain a specific statement thereon to the effect that
the indebtedness thereby evidenced is subject to the provisions of this
Agreement,



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and the Subordinated Creditor will mark its books conspicuously to evidence the
subordination effected hereby. Attached hereto is a true and correct copy of the
Subordinated Note bearing such legend. At the request of the Lender, the
Subordinated Creditor shall deposit with the Lender the Subordinated Note and
all of the other notes, bonds, debentures or other instruments evidencing the
Subordinated Indebtedness, which notes, bonds, debentures or other instruments
may be held by the Lender so long as any Lender Indebtedness remains
outstanding. The Subordinated Creditor is the lawful holder of the Subordinated
Note and has not transferred any interest therein to any other person. Without
the prior written consent of the Lender, the Subordinated Creditor will not
assign, transfer or pledge to any other person any of the Subordinated
Indebtedness or agree to a discharge or forgiveness of the same so long as there
remains outstanding any of the Lender Indebtedness.

         10. Continuing Effect. This Agreement shall constitute a continuing
agreement of subordination, and the Lender may, without notice to or consent by
the Subordinated Creditor, modify any term of the Lender Indebtedness in
reliance upon this Agreement. Without limiting the generality of the foregoing,
the Lender may, at any time and from time to time, either before or after
receipt of any such notice of revocation, without the consent of or notice to
the Subordinated Creditor and without incurring responsibility to the
Subordinated Creditor or impairing or releasing any of the Lender's rights or
any of the Subordinated Creditor's obligations hereunder:

          (a) change the interest rate or change the amount of payment or extend
     the time for payment or renew or otherwise alter the terms of any Lender
     Indebtedness or any instrument evidencing the same in any manner;

          (b) sell, exchange, release or otherwise deal with any property at any
     time securing payment of the Lender Indebtedness or any part thereof;

          (c) release anyone liable in any manner for the payment or collection
     of the Lender Indebtedness or any part thereof,

          (d) exercise or refrain from exercising any right against the Borrower
     or any other person (including the Subordinated Creditor); and

          (e) apply any sums received by the Lender, by whomsoever paid and
     however realized, to the Lender Indebtedness in such manner as the Lender
     shall deem appropriate.

         11. No Commitment. None of the provisions of this Agreement shall be
deemed or construed to constitute or imply any commitment or obligation on the
part of the Lender to make any future loans or other extensions of credit or
financial accommodations to the Borrower.

         12. Notice. All notices and other communications hereunder shall be in
writing and shall be (i) personally delivered, (ii) transmitted by registered
mail, postage prepaid, or (iii) transmitted by telecopy, in each case addressed
to the party to whom notice is being given at its address as set forth below:




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                  If to the Lender:

                  Wells Fargo Business Credit, Inc.
                  1740 Broadway
                  Denver, Colorado  80274-8625
                  Telecopier: (303) 863-4904
                  Attention: Tim Ulrich

                  If to the Subordinated Creditor:

                  Chaparral Network Storage, Inc.
                  1951 South Fordham
                  Longmont, Colorado  80503
                  Attention: Douglas Lehrmann
                  Telecopier: (303) 684-3201

or at such other address as may hereafter be designated in writing by that
party. All such notices or other communications shall be deemed to have been
given on (i) the date received if delivered personally, (ii) the date of posting
if delivered by mail, or (iii) the date of transmission if delivered by
telecopy.

         13. Conflict in Agreements. If the subordination provisions of any
instrument evidencing Subordinated Indebtedness conflict with the terms of this
Agreement, the terms of this Agreement shall govern the relationship between the
Lender and the Subordinated Creditor.

         14. No Waiver. No waiver shall be deemed to be made by the Lender of
any of its rights hereunder unless the same shall be in writing signed on behalf
of the Lender, and each such waiver, if any, shall be a waiver only with respect
to the specific matter or matters to which the waiver relates and shall in no
way impair the rights of the Lender or the obligations of the Subordinated
Creditor to the Lender in any other respect at any time.

         15. Binding Effect, Acceptance. This Agreement shall be binding upon
the Subordinated Creditor and the Subordinated Creditor's heirs, legal
representatives, successors and assigns and shall inure to the benefit of the
Lender and its participants, successors and assigns irrespective of whether this
or any similar agreement is executed by any other Subordinated Creditor of the
Borrower. Notice of acceptance by the Lender of this Agreement or of reliance by
the Lender upon this Agreement is hereby waived by the Subordinated Creditor.

         16. Miscellaneous. The paragraph headings herein are included for
convenience of reference only and shall not constitute a part of this Agreement
for any other purpose. This Agreement may be executed in any number of
counterparts, each of which shall be an original, but all of which together
shall constitute one instrument.

         17. Governing Law; Consent to Jurisdiction and Venue; Waiver of Jury
Trial. This Agreement shall be governed by and construed in accordance with the
substantive laws (other than



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conflict laws) of the State of Colorado. Each party consents to the personal
jurisdiction of the state and federal courts located in the State of Colorado in
connection with any controversy related to this Agreement, waives any argument
that venue in any such forum is not convenient, and agrees that any litigation
initiated by any of them in connection with this Agreement shall be venued in
either the District Court for the City and County of Denver, or the United
States District Court, District of Colorado. THE PARTIES WAIVE ANY RIGHT TO
TRIAL BY JURY IN ANY ACTION OR PROCEEDING BASED ON OR PERTAINING TO THIS
ACKNOWLEDGMENT.

         IN WITNESS WHEREOF, the Subordinated Creditor has executed this
Agreement as of the date and year first above-written.


                                   /s/ William R. Childs
                                   --------------------------------------
                                   William R. Childs




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                           Acknowledgment by Borrower

         The undersigned, being the Borrower referred to in the foregoing
Agreement, hereby (i) acknowledges receipt of a copy thereof, (ii) agrees to all
of the terms and provisions thereof, (iii) agrees to and with the Lender that it
shall make no payment on the Subordinated Indebtedness that the Subordinated
Creditor would not be entitled to receive under the provisions of the Agreement,
(iv) agrees that any such payment will constitute a default under the Lender
Indebtedness, and (v) agrees to mark its books conspicuously to evidence the
subordination of the Subordinated Indebtedness effected hereby.


                                     CHAPARRAL NETWORK STORAGE, INC.

                                     By /s/ Douglas J. Lehrmann
                                       ------------------------------------
                                       Its Vice President, Finance
                                          ---------------------------------




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