<PAGE>

                                  EXHIBIT 10.27

                        AMENDMENT TO EMPLOYMENT AGREEMENT

     This amendment to Employment Agreement (the "Amendment") is entered into 
as of June 11, 1997 by and between Ram Banin (the "Employee") and TCSI 
Corporation, a Nevada corporation (the "Employer").  The Amendment is an 
amendment to the Employment Agreement dated as of May 11, 1992 by and between 
Employee and Teknekron Communications Systems, Inc. Employer's predecessor 
(the "1992 Agreement").

AMENDMENT.  Except as herein amended, all of the terms and conditions of the 
1992 Agreement remain in full force and effect.

TERM OF EMPLOYMENT.  Paragraph 2 of the 1992 Agreement is deleted in its 
entirety and replaced with the following:

     2.   TERM OF EMPLOYMENT.  The employment relationship between Employee and
     Employer may be terminated by either party at any time, with or without
     cause, upon thirty (30) days written notice, subject to the terms of
     paragraph 15.

THE FOLLOWING PARAGRAPHS ARE ADDED TO THE 1992 AGREEMENT:

     14.  CHANGE OF CONTROL.
     
          (a)  In the event of a change in control of Employer, as defined
     immediately below, all Employee's options shall be deemed exercisable
     vested options, regardless of their vesting date, prior to the consummation
     of such transaction.  Moreover, Employee shall be entitled to any other
     acceleration of stock vesting and no less favorable terms respecting any
     acceleration of vesting than granted to any other executive of Employer.
     
          (b)  A "change in control of Employer" shall mean: a merger
     transaction or sale of stock by existing shareholders of Employer to a
     single purchaser or group of affiliated purchasers, as a result of either
     of which actions shareholders of Employer's voting capital stock
     immediately prior to such transaction do not own at least a majority of the
     outstanding shares (or other equivalent evidence of ownership) immediately
     following such transaction; or, a sale of all or substantially all of
     Employer's assets to a third party.
     
     15.  TERMINATION OF EMPLOYMENT
     
          (a)  TERMINATION BY EMPLOYER WITH CAUSE.  In the event Employer
     terminates Employee's employment for cause, all compensation and benefits
     under the 1992 Agreement as hereby amended shall cease.  Cause is defined
     as:
     
               (i)  the willful and continued failure by Employee to
               substantially perform his duties hereunder, after demand therefor
               is delivered by the Employer in writing; or

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               (ii) the willful engaging by Employee in misconduct which is
               materially injurious to the Employer.
               
               (iii)     No act or failure to act by Employee shall be
               considered "willful" unless done or omitted by him in bad faith
               and without reasonable belief that his action or omission was in
               the best interest of Employer.
               
          (b)  TERMINATION BY EMPLOYER WITHOUT CAUSE.  In the event Employer
               terminates Employee without cause, as cause is above defined,
               Employer shall continue Employee's salary and target bonus,
               benefits, stock option grants and vesting for a period of one (1)
               year.
          
          (c)  TERMINATION BY EMPLOYEE.  A termination by Employee shall be
               deemed a "termination without cause" and the provisions of sub-
               paragraph 15(b) above shall apply should Employee terminate his
               employment for any of the following reasons after providing (30)
               days written notice to Employer:
          
               (i)   if there occurs a change in control of Employer (as defined
          above); or
               
               (ii)  if there has been a failure by the Employer to comply with
          any material provision of the 1992 Agreement as hereby amended, which
          has not been cured with ten (10) days after notice thereof
          
               (iii) if there is a change in the place of employment beyond
          the San Francisco Bay Area
          
               (iv)  if there is material reduction in the Employee's base
          salary, bonus, benefits or responsibilities.
          
     16.  ARBITRATION.   Any controversy between Employer and Employee arising
          under or in connection with the 1992 Agreement, as hereby amended,
          shall on the written request of either party served on the other, be
          submitted to final and binding arbitration and judgment on the award
          rendered by the arbitrator may be entered in any court having
          jurisdiction.  arbitration shall comply and be governed by the
          provisions of the Employment Arbitration Rules of the American
          Arbitration Association.  The cost of arbitration and reasonable
          attorney fees of the prevailing party in any such arbitration shall be
          borne by the losing party.
     
     17.  ATTORNEY FEES AND COSTS.  If any arbitration or action at law or in
          equity is necessary to enforce or interpret the terms of the 1992
          Agreement, as hereby amended, the prevailing party shall be entitled
          to reasonable attorneys' fees and costs in addition to any other
          relief to which that party may be entitled.  This provision shall be
          construed as applicable to the entire contract.
     
     TCSI Corporation                          Ram Banin
     /s/ John C. Bolger                        /s/ Ram A. Banin            
     -------------------------------           ----------------------------
     By:  Chairman
     Its: Compensation Committee


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Teknekron Communications Systems

--------------------------------------------------------------------------------
                             EMPLOYMENT AGREEMENT
--------------------------------------------------------------------------------

THIS EMPLOYMENT AGREEMENT is entered into as of the 11th day of May, 1992 by and
between Ram Banin (the "EMPLOYEE") and Teknekron Communications Systems, Inc.
(the "EMPLOYER").

1.   EMPLOYMENT.  EMPLOYER employs EMPLOYEE, and EMPLOYEE accepts employment
     with EMPLOYER, on the terms and conditions set forth in the Agreement.

2.   TERMS OF EMPLOYMENT.  The employment relationship between EMPLOYEE and
     EMPLOYER may be terminated as follows:

     (a)  During the first (90) days of employment, either party may terminate
          without prior notice and for any reason whatsoever, or for no reason
          and without cause; or
     
     (b)  After the first ninety (90) days of employment, either party may
          terminate for any reason whatsoever, or for no reason and without
          cause, upon the giving of (i) two weeks' written notice to the other
          party or (ii) pay equal two (2) weeks of EMPLOYEE's salary in lieu of
          such notice; or
     
     (c)  At any time, EMPLOYER may terminate EMPLOYEE without prior notice if
          EMPLOYEE materially fails to perform any obligation or duty owed to
          EMPLOYER.

3.   DUTIES.  EMPLOYEE shall perform such tasks and duties as may be assigned by
     EMPLOYER, from time to time.  At all times EMPLOYEE shall follow all of
     EMPLOYER's legal instructions and directions and shall abide by all of
     EMPLOYER's rules and procedures in force from time to time while employed. 
     EMPLOYEE shall devote his full time, attention, skill and efforts to the
     tasks and duties assigned by EMPLOYER.  Without the prior written consent
     of EMPLOYER, EMPLOYEE shall not provide services, for compensation, to any
     other person or business entity while employed by EMPLOYER.

     EMPLOYEE understands and acknowledges that EMPLOYER has a policy not to
     engage directly or indirectly, deliberately or inadvertently, in any
     recruitment or employment policies that cause the EMPLOYEE to violate any
     contract commitment such EMPLOYEE may have with a prior EMPLOYER or other
     third party.  By accepting employment, EMPLOYEE certifies that no such
     conflict exists and that any questions regarding a potential conflict have
     been fully disclosed in writing to EMPLOYER.

4.   COMPENSATION.  As compensation for all services to be rendered by EMPLOYEE
     to EMPLOYER, EMPLOYEE shall be paid a salary at the annual rate of
     $165,000.00.  Said salary shall be payable in accordance with EMPLOYER's
     standard procedures.  EMPLOYER shall withhold from any amounts payable as
     compensation all federal state, municipal or other taxes as are required by
     any law, regulation or ruling.

     (a)  EMPLOYEE understands and agrees that EMPLOYEE's salary may be adjusted
          by EMPLOYER prospectively, and at its sole discretion from time to
          time, without affecting the remaining terms of this Agreement.
     
     (b)  EMPLOYEE understands and agrees that any other compensation that may
          be paid to EMPLOYEE for services rendered, or to be rendered, (whether
          by way of an incentive payment, 


<PAGE>

          opportunity to acquire stock or any other form of additional
          compensation) shall rest in the sole discretion of EMPLOYER.

5.   PROPERTY RIGHTS; DUTY TO DISCLOSE.  EMPLOYEE hereby acknowledges and agrees
     to be bound by the provisions of the EMPLOYER's "Non-Disclosure/Assignment
     Agreement" attached hereto as Exhibit A and made a part hereof by this
     reference as though set forth in full herein.  The provisions of Exhibit A
     shall survive any termination of this Agreement.

6.   NONSOLICITATION OF EMPLOYEES.  EMPLOYEE specifically agrees that during the
     term of this Agreement and for a period of one (1) year thereafter,
     EMPLOYEE shall not, directly or indirectly, either for himself or for any
     other person, firm, corporation or other legal entity, solicit any then
     employee of EMPLOYER to leave the employment of EMPLOYER.

7.   NO ASSIGNMENT.  This Agreement may not be assigned by EMPLOYEE without the
     written consent of EMPLOYER.  This Agreement shall be binding on the heirs,
     executors, administrators, personal representatives, successors and assigns
     of EMPLOYEE and EMPLOYER.

8.   GOVERNING LAW.  This Agreement shall be governed by and construed and
     enforced in accordance with and subject to the laws of the State where the
     EMPLOYEE was principally rendering services for EMPLOYER.

9.   NOTICES.  All notices or other communications provided for or by this
     Agreement shall be made in writing and shall be deemed properly delivered
     when (i) delivered personally or (ii) by the mailing of such notice by
     registered or certified mail, postage prepaid, to the parties at the
     addresses set forth on the signature page of this Agreement (or to such
     other address as one party designates to the other in writing).

10.  ENTIRE AGREEMENT AND WAIVER.  This Agreement is the entire agreement
     between the parties relating to EMPLOYEE's employment.  It supersedes all
     prior agreements, arrangements, negotiations and understandings related
     thereto.  No waiver of any term, provision or condition of this Agreement
     shall be deemed to be, or shall constitute, a waiver of any other term,
     provision of condition herein, whether or not similar.  No such waiver
     shall be binding unless in writing and signed by the waiving party.

11.  AMENDMENTS.  No supplement, modification or amendment of any term,
     provision or condition of this Agreement shall be binding or enforceable
     unless evidenced in writing executed by the parties hereto.

12.  COUNTERPARTS.  This Agreement may be executed in one or more counterparts,
     each of which shall be deemed an original, but all of which together shall
     constitute one and the same instrument.

13.  REFORMATION/SERVERABILITY.  In any provision of this Agreement is declared
     invalid by any tribunal, then such provision shall be deemed automatically
     adjusted to the minimum extent necessary to conform to the requirements for
     validity as declared at such time and, as so adjusted, shall be deemed a
     provision of this Agreement as though originally included herein.  In the
     event that the provision invalidated is of such a nature that it cannot be
     so adjusted, the provision shall be deemed deleted from this Agreement as
     though such provision had never been included herein.  In either case, the
     remaining provisions of this Agreement shall remain in effect.

<PAGE>

After carefully reading and considering the foregoing provisions and Exhibit 
A, EMPLOYEE has voluntarily signed this Agreement on as of the date first 
above written.

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COMPANY:                                   EMPLOYEE:
--------------------------------------------------------------------------------

Teknekron Communications Systems, Inc.     /s/Ram A. Banin                      
---------------------------------------    -------------------------------------
Name of Company                            EMPLOYEE Signature

2121 Allston Way                                                 
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Address                                    Address

Berkeley, CA  94704                                              
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City, State                                City, State


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                                           Telephone

                                                                 
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                                           Social Security #

                                           5/7/92                        
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                                           Date