PROMISSORY NOTE EXHIBIT 10.1

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Principal Loan Date  Maturity   Loan No.  Call Collateral Acct  Officer Initials
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$400,000  10-14-1997 10-14-1998 404022113 10   09         551876 111
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 References in the shaded area are for Lender's use only and do not limit the
 applicability of this document to any particular loan or item.
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Borrower:  HYTEK MICROSYSTEMS, INC. (TIN: 94-2234140)   Lender: SierraWest Bank
           400 HOT SPRINGS RD.                                  Reno Main Office
           CARSON CITY, NV  89706-1609                          P. O. BOX 10925
                                                                RENO, NV 89510
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Principal Amount: $400,000 Initial Rate: 10.000% Date of Note: October 14, 1997

PROMISE  TO  PAY.  HYTEK  MlCROSYSTEMS,  INC,  ("Borrower")  promises  to pay to
SierraWest  Bank  ("Lender"),  or order, in lawful money of the United States of
America,  the  principal  amount  of Four  Hundred  Thousand  &  00/100  Dollars
($400,000.00)  or so much as may be  outstanding,  together with interest on the
unpaid  outstanding  principal  balance  of  each  advance.  Interest  shall  be
calculated from the date of each advance until repayment of each advance.

PAYMENT. Borrower will pay this loan in one payment of all outstanding principal
plus all accrued unpaid interest on October 14, 1998. In addition, Borrower will
pay regular monthly payments of accrued unpaid interest  beginning  November 15,
1997, and all subsequent interest payments are due on the same day of each month
after  that.  The annual  interest  rate for this Note is  computed on a 365/360
basis; that is, by applying the ratio of the annual interest rate over a year of
360 days,  multiplied by the outstanding  principal  balance,  multiplied by the
actual number of days the principal  balance is  outstanding.  Borrower will pay
Lender at  Lender's  address  shown  above or at such other  place as Lender may
designate in writing.  Unless  otherwise  agreed or required by applicable  law,
payments will be applied first to accrued  unpaid  interest,  then to principal,
and any remaining amount to any unpaid collection costs and late charges.

VARIABLE INTEREST RATE. The interest rate on this Note is subject to change from
time to time based on changes in an independent index which is the Prime Rate as
published in the WESTERN  EDITION OF THE WALL STREET JOURNAL (the "Index").  The
Index is not  necessarily the lowest rate charged by Lender on its loans. If the
Index becomes  unavailable  during the term of this loan, Lender may designate a
substitute index after notice to Borrower. Lender will tell Borrower the current
Index rate upon Borrower's  request.  Borrower  understands that Lender may make
loans based on other rates as well. The interest rate change will not occur more
often than each day. The Index currently is 8.500% per annum.  The interest rate
to be applied to the unpaid principal  balance of this Note will be at a rate of
1.500 percentage points over the Index,  resulting in an initial rate of 10.000%
per annum. NOTICE: Under no circumstances will the interest rate on this Note be
more than the maximum rate allowed by applicable law.

PREPAYMENT. Borrower agrees that all loan fees and other prepaid finance charges
are  earned  fully as of the date of the loan and will not be  subject to refund
upon early  payment  (whether  voluntary or as a result of  default),  except as
otherwise  required by law.  Except for the foregoing,  Borrower may pay without
penalty  all or a portion  of the  amount  owed  earlier  than it is due.  Early
payments will not,  unless agreed to by Lender in writing,  relieve  Borrower of
Borrower's  obligation to continue to make payments of accrued unpaid  interest.
Rather, they will reduce the principal balance due.

LATE  CHARGE.  If a payment  is 10 days or more late,  Borrower  will be charged
5.000% of the regularly scheduled payment or $15.00, whichever is greater.

DEFAULT.  Borrower  will be in  default  if any of the  following  happens:  (a)
Borrower  fails to make any payment when due.  (b)  Borrower  breaks any promise
Borrower has made to Lender, or Borrower fails to comply with or to perform when
due any other term, obligation, covenant, or condition contained in this Note or
any agreement  related to this Note, or in any other  agreement or loan Borrower
has with Lender.  (c)  Borrower  defaults  under any loan,  extension of credit,
security  agreement,  purchase or sales agreement,  or any other  agreement,  in
favor of any  other  creditor  or  person  that  may  materially  affect  any of
Borrower's  property  or  Borrower's  ability  to  repay  this  Note or  perform
Borrower's obligations under this Note or any of the Related Documents.  (d) Any
representation  or  statement  made or  furnished  to Lender by  Borrower  or on
Borrower's  behalf is false or misleading in any material  respect either now or
at the time made or furnished.  (e) Borrower  becomes  insolvent,  a receiver is
appointed for any part of Borrower's property,  Borrower makes an assignment for
the benefit of creditors,  or any proceeding is commenced  either by Borrower or
against Borrower under any bankruptcy or insolvency laws. (f) Any creditor tries
to take any of Borrower's  property on or in which Lender has a lien or security
interest. This includes a garnishment of any of Borrower's accounts with Lender.
(g) Any  guarantor  dies or any of the other  events  described  in this default
section  occurs  with  respect to any  guarantor  of this  Note.  (h) A material
adverse change occurs in Borrower's financial condition,  or Lender believes the
prospect of payment or performance of the  Indebtedness is impaired.  (i) Lender
in good faith deems itself insecure.

If any default,  other than a default in payment, is curable and if Borrower has
not been given a notice of a breach of the same  provision  of this Note  within
the preceding twelve (12) months,  it may be cured (and no event of default will
have occurred) if Borrower, after receiving written notice from Lender demanding
cure of such default:  (a) cures the default within fifteen (15) days; or (b) if
the cure requires more than fifteen (15) days, immediately initiates steps which
Lender deems in Lender's  sole  discretion  to be sufficient to cure the default
and  thereafter  continues  and  completes all  reasonable  and necessary  steps
sufficient to produce compliance as soon as reasonably practical.

LENDER'S  RIGHTS.  Upon default,  Lender may declare the entire unpaid principal
balance on this Note and all accrued unpaid interest  immediately  due,  without
notice, and than Borrower will pay that amount. Upon default,  including failure
to pay upon final maturity,  Lender, at its option, may also, if permitted under
applicable  Iaw,  increase  the  variable  interest  rate on this  Note to 6.500
percentage  points over the Index; The interest rate will not exceed the maximum
rate  permitted by applicable  law.  Lender may hire or pay someone else to help
collect this Note if Borrower  does not pay.  Borrower also will pay Lender that
amount.  This includes,  subject to any limits under  applicable  law,  Lender's
attorneys'  fees and Lender's legal expenses  whether or not there is a lawsuit,
including  attorneys'  fees  and  legal  expenses  for  bankruptcy   proceedings
(including  efforts  to modify  or vacate  any  automatic  stay or  injunction),
appeals,  and  any  anticipated   post-judgment   collection  services.  If  not
prohibited  by  applicable  law,  Borrower  also  will pay any court  costs,  in
addition to all other sums  provided  by law.  This Note has been  delivered  to
Lender and  accepted  by Lender in the State of  Nevada.  If there is a lawsuit,
Borrower  agrees  upon  Lender's  request to submit to the  jurisdiction  of the
courts of Washoe County, the State of Nevada (Initial Here ). This Note shall be
governed by and construed in accordance with the laws of the State of Nevada.

RIGHT OF SETOFF.  Borrower  grants to Lender a contractual  possessory  security
interest in, and hereby assigns,  conveys,  delivers,  pledges, and transfers to
Lender all Borrower's right,  title and interest in and to, Borrower's  accounts
with  Lender  (whether  checking,  savings,  or some other  account),  including
without  limitation all accounts held jointly with someone else and all accounts
Borrower may open in the future,  excluding  however all IRA and Keogh accounts,
and all trust  accounts  for which the  grant of a  security  interest  would be
prohibited  by law.  Borrower  authorizes  Lender,  to the extent  permitted  by
applicable  law, to charge or setoff all sums owing on this Note against any and
all such accounts.

LINE OF CREDIT.  This Note evidences a revolving line of credit.  Advances under
this Note may be  requested  either  orally or in writing by  Borrower  or by an
authorized  person.  Lender may, but need not, require that all oral requests be
confirmed  in  writing.  All  communications,  instructions,  or  directions  by
telephone  or  otherwise  to Lender are to be directed to Lender's  office shown
above.  The following party or parties are authorized to request  advances under
the line of credit until Lender receives from Borrower at Lender's address shown
above  written  notice of  revocation  of their  authority:  CHARLES  S.  BRYNE,
PRESIDENT/CEO/SECRETARY.  Borrower agrees to be liable for all sums either:  (a)
advanced in accordance  with the  instructions  of an  authorized  person or (b)
credited to any of Borrower's accounts with Lender. The unpaid principal balance
owing on this Note at any time may be evidenced by  endorsements on this Note or
by Lender's internal records,  including daily computer  printouts.  Lender will
have no  obligation  to advance  funds  under this Note if: (a)  Borrower or any
guarantor  is in  default  under the terms of this  Note or any  agreement  that
Borrower or any  guarantor  has with Lender,  including  any  agreement  made in
connection  with the signing of this Note; (b) Borrower or any guarantor  ceases
doing  business or is insolvent;  (c) any guarantor  seeks,  claims or otherwise
attempts to limit,  modify or revoke such guarantor's  guarantee of this Note or
any other loan with Lender;  (d) Borrower has applied funds provided pursuant to
this Note for purposes other than those  authorized by Lender;  or (e) Lender in
good faith deems itself insecure under this Note or any other agreement  between
Lender and Borrower.

ZERO  BALANCE  REQUIREMENT.  Notwithstanding  any other  provision  in this Note
including  the  provisions  regarding  advances  and  payments,  Borrower  shall
maintain an outstanding balance of $0 during a period of thirty (30) consecutive
days during each one-year.

GENERAL  PROVlSIONS.  Lender may delay or forgo  enforcing  any of its rights or
remedies under this Note without losing them.  Borrower and any other person who
signs,  guarantees or endorses this Note,  to the extent  allowed by law,  waive
presentment, demand for payment, protest and notice of dishonor. Upon any change
in the terms of this Note, and unless otherwise  expressly stated in writing, no
party who signs this Note, whether as maker,  guarantor,  accommodation maker or
endorser,  shall be released from liability.  All such parties agree that Lender
may renew or  extend  (repeatedly  and for any  Iength of time)  this  loan,  or
release any party or guarantor or collateral; or impair, fail to realize upon or
perfect Lender's security interest in the collateral;  and take any other action
deemed necessary by Lender without the consent of or notice to anyone.  All such
parties  also agree that Lender may modify  this loan  without the consent of or
notice to anyone other than the party with whom the modification is made.

PRIOR TO SIGNING THIS NOTE,  BORROWER READ AND  UNDERSTOOD ALL THE PROVISIONS OF
THIS NOTE,  INCLUDING THE VARIABLE INTEREST RATE PROVISIONS.  BORROWER AGREES TO
THE TERMS OF THE NOTE AND ACKNOWLEDGES RECEIPT OF A COMPLETED COPY OF THE NOTE.


BORROWER:

HYTEK MICROSYSTEMS, INC.


By:               /S/ Charles S. Byrne
         --------------------------------------
         CHARLES S. BRYNE, PRESIDENT/CEO/SECRETARY


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Variable   Rate.   Line  of  Credit.   LASER  PRO,  
Reg.  U.S.   Pat.  &  T.M.   Off.,   Ver.  3.24  (c)  1997  CFI ProServices, 
Inc.  All rights reserved.  [NV-D20 HYTEK1.LN C1.OVL]Line of Credit.

FINANCE/CHUCK/PROMNOTE