EXHIBIT NUMBER 10.9


            FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT
                                 (MULTICURRENCY)


         THIS  FIRST  AMENDMENT  TO  AMENDED  AND  RESTATED   CREDIT   AGREEMENT
(MULTICURRENCY) (the "Amendment"),  dated as of December 5, 1996 is entered into
by and between  STANFORD  TELECOMMUNICATIONS,  INC. (the "Borrower") and BANK OF
AMERICA NATIONAL TRUST AND SAVINGS ASSOCIATION (the "Bank").

                                    RECITALS

         A. The  Borrower  and the Bank are parties to an Amended  and  Restated
Credit  Agreement  (Multicurrency)  dated as of December  5, 1996  (the  "Credit
Agreement") pursuant to which the Bank has extended certain credit facilities to
the Borrower.

         B. The Borrower has requested that the Bank agree to certain amendments
of the Credit Agreement.

         C. The Bank is willing to amend the  Credit  Agreement,  subject to the
terms and conditions of this Amendment.

         NOW, THEREFORE, for valuable consideration, the receipt and adequacy of
which are hereby acknowledged, the parties hereto hereby agree as follows:

         1. Defined Terms.  Unless otherwise  defined herein,  capitalized terms
used  herein  shall have the  meanings,  if any,  assigned to them in the Credit
Agreement.

         2. Amendments to Credit Agreement.

            (a)  Section  1.01 of the Credit  Agreement  shall be amended at the
defined term  "Availability  Period" by amending and restating such defined term
as follows:

            "'Availability  Period':  the period  commencing on the date of this
Agreement  and ending on the date that is the  earlier to occur of (a)  December
18,  1997,  and (b) the date on which the  Bank's  commitment  to extend  credit
hereunder terminates."

            (b)  Section  1.01 of the Credit  Agreement  shall be amended at the
defined term "Final  Maturity  Date" by amending and restating such defined term
as follows:

            "'Final Maturity Date': (a) in respect of any Advances, December 18,
            1997; (b) in respect of any commercial  letters of credit,  June 18,
            1998; (c) in respect of any standby letters of credit,  December 18,
            1998; (d) in respect of any Bank Guaranties,  December 18, 1998; and
            (e) in respect of any acceptances, June 18, 1998."

            (c)  Section  7.13 of the  Credit  Agreement  shall be  amended  and
restated in its entirety so as to read as follows:

            "7.13 Tangible Net Worth. The Borrower shall not permit its Tangible
Net Worth on a consolidated  basis at any time to be less than  $70,000,000 plus
75% of the Borrower's  consolidated  net income (but not less any net losses for
any period) earned in each fiscal quarter

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commencing after September 30, 1996 plus the value of all Net Issuance  Proceeds
(whether in cash, other property or in kind) of equity  securities issued by the
Borrower  from and after  September  30, 1996.  For purposes of this Section and
Section 7.14,  "Tangible Net Worth" means, as of any date of determination,  (i)
total  assets  (exclusive  of  goodwill,  patents,   trademarks,   trade  names,
organization  expense,  treasury shares,  unamortized debt discount and premium,
deferred charges and other like intangibles)  less (ii) all reserves  applicable
thereto and all  liabilities  (including  accrued and deferred  income taxes and
subordinated liabilities). For purposes of this Section, "Net Issuance Proceeds"
means,  in respect  of any  issuance  of common or  preferred  equity,  proceeds
(whether in cash, other property,  or in kind) received in connection therewith,
net of out-of-pocket costs and expenses paid or incurred in connection therewith
in favor of any person not an  affiliate of the Borrower and not to exceed 5% of
the gross proceeds thereof."

            (d) Schedule 2 to Exhibit A of the Credit Agreement shall be
amended and  restated  in its  entirety so as to read as set forth in Schedule 2
attached hereto.

         3.  Representations and Warranties.  The Borrower hereby represents and
warrants to the Bank as follows:

            (a) No Default or Event of Default has occurred and is continuing.

            (b) The execution,  delivery and performance by the Borrower of this
Amendment have been duly authorized by all necessary  corporate and other action
and do not and will not require any registration  with,  consent or approval of,
notice to or action by, any person  (including  any  governmental  authority) in
order to be effective and  enforceable.  The Credit Agreement as amended by this
Amendment  constitutes the legal, valid and binding obligations of the Borrower,
enforceable against it in accordance with its respective terms, without defense,
counterclaim or offset.

            (c) All  representations and warranties of the Borrower contained in
the Credit Agreement are true and correct.

            (d) The Borrower is entering into this Amendment on the basis of its
own investigation and for its own reasons, without reliance upon the Bank or any
other person.

         4.  Effective  Date. The amendments set forth in Sections 2(a) and 2(b)
hereof will become  effective as of December 19, 1996,  and the  amendments  set
forth in Sections  2(c) and 2(d) hereof  will  become  effective  as of the date
first above written,  provided that each of the following  conditions  precedent
has been satisfied:

            (a) The Bank has received from the Borrower a duly executed original
of this Amendment.

                  (b) The  Bank  has  received  from  the  Borrower  a copy of a
resolution  passed by the board of directors of such  corporation,  certified by
the  Secretary or an Assistant  Secretary of such  corporation  as being in full
force and effect on the date hereof,  authorizing  the  execution,  delivery and
performance of this Amendment.

         5. Reservation of Rights. The Borrower acknowledges and agrees that the
execution  and  delivery  by the Bank of this  Amendment  shall not be deemed to
create a course of dealing or otherwise  obligate the Bank to forbear or execute
similar amendments under the same or similar circumstances in the future.


<PAGE>


         6.         Miscellaneous.

            (a) Except as herein  expressly  amended,  all terms,  covenants and
provisions of the Credit Agreement are and shall remain in full force and effect
and all references  therein to such Credit  Agreement shall  henceforth refer to
the Credit  Agreement  as amended by this  Amendment.  This  Amendment  shall be
deemed incorporated into, and a part of, the Credit Agreement.

            (b) This Amendment shall be binding upon and inure to the benefit of
the parties hereto and thereto and their respective  successors and assigns.  No
third party beneficiaries are intended in connection with this Amendment.

            (c) This Amendment  shall be governed by and construed in accordance
with the law of the State of California.

            (d) This  Amendment  may be executed in any number of  counterparts,
each of which shall be deemed an original,  but all such  counterparts  together
shall  constitute  but one and the same  instrument.  Each of the parties hereto
understands  and agrees  that this  document  (and any other  document  required
herein) may be delivered by any party thereto  either in the form of an executed
original or an executed  original sent by facsimile  transmission to be followed
promptly by mailing of a hard copy  original,  and that receipt by the Bank of a
facsimile transmitted document purportedly bearing the signature of the Borrower
shall bind the Borrower with the same force and effect as the delivery of a hard
copy  original.  Any  failure  by the Bank to  receive  the hard  copy  executed
original of such  document  shall not diminish the binding  effect of receipt of
the facsimile  transmitted  executed  original of such document  which hard copy
page was not received by the Bank.

            (e) This Amendment, together with the Credit Agreement, contains the
entire and  exclusive  agreement  of the parties  hereto with  reference  to the
matters discussed herein and therein. This Amendment supersedes all prior drafts
and  communications  with respect thereto.  This Amendment may not be amended or
modified except in writing executed by both of the parties hereto.

            (f) If any term or  provision  of this  Amendment  shall  be  deemed
prohibited  by or invalid under any  applicable  law,  such  provision  shall be
invalidated without affecting the remaining  provisions of this Amendment or the
Credit Agreement, respectively.

            (g) Borrower covenants to pay to or reimburse the Bank, upon demand,
for all costs and  expenses  (including  allocated  costs of  in-house  counsel)
incurred in connection with the development, preparation, negotiation, execution
and delivery of this Amendment.

<PAGE>

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



                                            STANFORD TELECOMMUNICATIONS, INC.



                                            By:      /s/ Gary Wolf
                                            ------------------------------------
                                            Name:
                                            Title:    Vice President & CEO


                                            By:   /s/ Chris Smallman
                                            ------------------------------------
                                            Name:
                                            Title:  Corporate Controller



                                            BANK OF AMERICA NATIONAL TRUST
                                            AND SAVINGS ASSOCIATION



                                            By:   /s/ Debra G. Staiger
                                            ------------------------------------
                                            Name:
                                            Title:  Vice President