EXHIBIT 10.9

            SECOND AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT
                                 (MULTICURRENCY)

         THIS  SECOND   AMENDMENT  TO  AMENDED  AND  RESTATED  CREDIT  AGREEMENT
(MULTICURRENCY)  (the  "Amendment"),  dated as of December 12, 1997,  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 20, 1995, as amended by a
First Amendment to Amended and Restated Credit Agreement  (Multicurrency)  dated
as of  December 5, 1996 (as so amended,  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, 1998,  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  Maturitv  Date':  (a) in  respect  of  any  Advances,
                  December 18, 1998;
                  (b) in respect of any commercial  letters of credit,  June 18,
                  1999;
                  (c) in respect of any standby letters of credit,  December 17,
                  1999;
                  (d) in respect of any Bank Guaranties, December 17, 1999; and
                  (e) in respect of any acceptances, June 18, 1999."
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         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) That certain  resolution  of the Board of Directors of the
Borrower dated March 28, 1991, which authorizes the credit  facilities  provided
under the Credit  Agreement  remains in full force and  effect.  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. This Second  Amendment will become  effective as of
the date first above written (the "Effective Date"),  provided that the Bank has
received from the Borrower a duly executed original (or, if elected by the Bank,
an executed facsimile copy) 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.

         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  baneficiaries  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.
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                  (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 mod)fied 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 reasonable  costs and expenses  (including  allocated  costs of
in-house  counsel)  incurred in connection  with the  development,  preparation,
negotiation, execution and delivery of this Amendment.

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

                                        STANFORD TELECOMMUNICATIONS, INC.


                                        By:      /s/ Jerome F. Klajbor
                                                 ---------------------
                                        Name:    Jerome F. Klajbor
                                        Title:   Chief Financial Officer

                                        BANK OF AMERICA NATIONAL TRUST
                                        AND SAVINGS ASSOCIATION


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