AMENDED AND RESTATED
SUPPLEMENT TO NOTE AND SECURITY AGREEMENT



This  Amended and  Restated  Supplement  to Note and  Security  Agreement  (this
"Supplement")  is annexed to and is part of the  Amended and  Restated  Note and
Security  Agreement,  dated December 30, 1997 of  Undersigned  payable to MELLON
BANK,  N.A.  ("Bank") in the stated  principal  amount of  TWENTY-THREE  Million
Dollars  and No Cents  ($23,000,000.00).  Such Note and  Security  Agreement  as
supplemented by this Supplement, shall be referred to as the "Note".

1. Payment.  Principal on the Note shall be due and payable on October 30, 1998.
Accrued  interest on the Prime Rate Portion,  ABS Rate  Portion,  and As Offered
Rate Portion  shall be due and payable on the last Business Day of each calendar
month  after the date  hereof and on October  30,  1998.  Interest  on each Rate
Segment of the  LIBOR-Rate  Portion  shall be due and payable on the last day of
the corresponding Rate Period, but in no case less frequently than 90 days after
the  previous  interest  payment on account of such  LIBOR-Rate  Portion.  After
maturity of any part of the Note (by  acceleration  or  otherwise),  interest on
such part of the Note shall be due and payable on demand.

2.  Interest Rate Options.  The unpaid  principal  amount of the Note shall bear
interest  for each day until due on one or more bases  selected  by  Undersigned
from among the interest rate options  ("Interest Rate Options") set forth below.
Undersigned  understands  and agrees:  (a) that Bank may in its sole  discretion
from time to time determine that the right of Undersigned to select,  convert to
or renew the Prime Rate Option,  the ABS Rate Option,  the LIBOR-Rate Option, or
As-Offered  Rate Option is not  available,  although  Bank agrees to make a good
faith  effort to provide all Interest  Rate  Options to  Borrower,  and (b) that
subject to the provisions of this Supplement,  Undersigned may select any number
of Interest  Rate  Options to apply  simultaneously  to  different  parts of the
unpaid  principal  amount of the Note and may select any number of Rate Segments
to apply simultaneously to different parts of the LIBOR-Rate Portion.

Available Interest Rate Options

          Prime Rate Option:  A rate per annum  (computed on the basis of a year
             Of 360 days and  actual  days  elapsed)  for each day  equal to the
             Prime Rate.

               ABS Rate  Option:  A rate per annum  (computed  on the basis of a
               year of 360 days and actual days  elapsed)  for each day equal to
               the ABS Rate for such day plus 110 Basis Points.

               LIBOR-Rate  Option:  For  each  Rate  Segment  of the  LIBOR-Rate
               Portion, a rate per annum (computed on the basis of a year of 360
               days  and  actual  days  elapsed)  for  each  day  equal  to  the
               LIBOR-Rate for such Rate Segment for such day plus 110 Basis.

               As-Offered Rate Option: For each Rate Segment of the As-Offered 
               Rate Portion, a rate per annum (computed on the basis of a year 
               of 360 days  and  actual  days  elapsed)  for  each  day  equal 
               to  the As-Offered Rate for such Rate Segment for such day plus 
               110 Basis Points.


3. Rate Periods. At any time when Undersigned selects, converts to or renews the
LIBOR-Rate Option or As-Offered Rate Option, Undersigned shall fix a period (the
"Rate  Period")  which shall be one, two, or three months and in the case of the
As-offered  Rate  Option,  shall be such number of days as Bank may offer at its
sole  discretion,  which shall be acceptable to Bank in Bank's sole  discretion,
during which the LIBOR-Rate  Option or As-Offered Rate Option shall apply to the
corresponding  Rate  Segment.  Bank's right to payment of principal and interest
under  the Note  shall in no way be  affected  by the fact that one or more Rate
Periods may be in effect.

4. Amounts. Every selection of, conversion to or renewal of the ABS Rate Option,
the LIBOR-Rate  Option,  or the  As-Offered  Rate Option shall be in a principal
amount  selected by  Undersigned  but limited to no more than four interest rate
segments at any one time.

5. Interest After Maturity.  After the principal amount of any part of the Prime
Rate  Portion or the ABS Rate Portion  shall have become due and  payable,  such
amount shall bear  interest for each day until paid (before and after  judgment)
at a rate per annum (based on a 360 day year and actual days elapsed)  which for
each day shall be the  greater of (a) 2% above the Prime Rate  Option on the day
such amount  became due and (b) 2% above the Prime Rate  Option,  such  interest
rate to change  automatically  from time to time  effective as of the  effective
date of each change in the Prime Rate. After the principal amount of any part of
the LIBOR-Rate  Portion or the As-Offered  Rate Option shall have become due and
payable,  such amount  shall bear  interest for each day until  paid (before and
after judgment) (a) until the end of the applicable  then-current Rate Period at
a rate per annum 2% above the LIBOR-Rate  Option or the  As-Offered  Rate Option
otherwise  applicable to such part and (b)  thereafter  in  accordance  with the
first sentence of this Section 5.

6. Late  Payment  Charge.  If any  payment  (including  without  limitation  any
regularly  scheduled  payment,  balloon  payment and final  payment) is not paid
within 25 days after it is due,  Undersigned  will pay a late charge equal to 5%
of the entire  payment due  (regardless  of whether  part of the payment due had
been made,  and  regardless of whether the payment due consists of principal and
interest,  principal  only or  interest  only).  (Such  late  charge  will be in
addition  to  any  increase  made  to the  interest  rate(s)  applicable  to the
outstanding balance hereof as a result of maturity of this Note or otherwise, as
well as in addition to any other applicable fees, charges and costs.) Also, Bank
reserves the right to modify,  in its sole  discretion and upon thirty (30) days
prior written notice to Undersigned, the late charge set forth herein.

7.  Selection,  Conversion  or  Renewal  of Rate  Options.  Subject to the other
provisions of this  Supplement,  Undersigned may select any interest Rate Option
to apply to any borrowing evidenced by the Note. Subject to the other provisions
of this  Supplement,  Undersigned  may convert any part of the unpaid  principal
amount of the Note from any  Interest  Rate  Option to any other  Interest  Rate
Option and may renew the  LIBOR-Rate  Option as to any Rate Segment:  (a) at any
time with respect to conversion from the Prime Rate Option or ABS Rate Option to
any other Interest Rate Option and (b) at the expiration of any Rate Period with
respect to conversion  from or renewals of the  LIBOR-Rate  Option or As-Offered
Rate Option as to the Rate Segment  corresponding  to such expiring Rate Period.
Whenever  Undersigned desires to select,  convert or renew the LIBOR-Rate Option
or As-Offered Rate Option,  Undersigned  shall give Bank Standard Notice thereof
(which  shall be  irrevocable),  specifying  the  date,  amount  and type of the
proposed new Interest  Rate Option.  If such notice has been duly given,  and if
Bank in its sole  discretion  (based  on a good  faith  effort  to  provide  all
Interest Rate Options) approves the proposed  selection,  conversion or renewal,
on and after the date specified in such notice interest shall be calculated upon
the unpaid  principal  amount of the Note taking into  account  such  selection,
conversion or renewal.

8. Prime Rate Fallback. If any Rate Period expires, any part of the Rate Segment
corresponding  to such Rate Period  which has not been  converted  or renewed in
accordance with Section 7 hereof  automatically  shall be converted to the Prime
Rate  Option.  If at any time the ABS Rate  Option is  determined  to exceed the
Prime Rate Option, the ABS Rate Portion shall automatically convert to the Prime
Rate  Option.  If  Undersigned  fails to  select,  or if Bank  fails to  approve
(because   an   Interest   Option  is  not   available   in  Bank's  good  faith
determination),  an Interest Rate Option to apply to any borrowing  evidenced by
the Note, such borrowing  shall be deemed to be at the Prime Rate Option.  If at
any time the Bank shall have determined in good faith (which determination shall
be conclusive)  that the accrual of interest at any of the Interest Rate Options
has been made  impractical or unlawful by compliance with the Bank in good faith
with any law (including common law), constitution,  statute, treaty, regulation,
rule, ordinance,  order, injunction,  writ, decree,  authority,  bureau, central
bank,  commission,  department  or  instrumentality  of  either,  or any  court,
tribunal, grand jury or arbitrator, in each case whether foreign or domestic, or
administration  thereof by any official body charged with the  interpretation or
administration  thereof or with any request or  directive  of any such  official
body (whether or not having the force of law),  then, and in any such event, the
Outstanding  principal  amount of this Note subject to such Interest Rate Option
shall  accrue  interest at the Prime Rate Option and the  Undersigned  shall not
have the right to select such Interest Rate Option.

9. Prepayments. Undersigned shall have the right at its option from time to time
to prepay  the Prime  Rate  Portion  and ABS Rate  Portion  in whole or in part.
Undersigned shall have no right to prepay any part of the LIBOR-Rate  Portion or
As-Offered  Rate Portion at any time without the prior  written  consent of Bank
except  that  Undersigned  may  prepay  any  part  of any  Rate  Segment  at the
expiration of the Rate Period  corresponding  to such Rate Segment.  Prepayments
shall be made by  giving  the  Bank  Standard  Notice  thereof  (which  shall be
irrevocable),  specifying the date, and amount and type of prepayment,  and upon
such date the amount so specified and accrued  interest thereon shall be due and
payable.

10.  Indemnity.  Undersigned  shall  indemnify  Bank against any loss or expense
(including loss of margin) which Bank has sustained or incurred as a consequence
of:

(i) payment,  prepayment  or  conversion  of any part of any Rate Segment of the
LIBOR-Rate  Portion or As-Offered  Rate Portion on a day other than the last day
of the corresponding Rate Period (whether or not any such payment is pursuant to
demand by Bank under the Note and whether or not any such payment, prepayment or
conversion is consented to by Bank, unless Bank shall have expressly waived such
indemnity in writing);

(ii) attempt by  Undersigned to revoke in whole or part any  irrevocable  notice
given pursuant to Section 6 of this Supplement; or


(iii) breach of or default by any obligor in the  performance  or  observance of
any covenant or condition  contained in the Loan Agreement (if any), the Note or
any separate  security,  guarantee or suretyship  agreement between Bank and any
Obligor.

If Bank  sustains  any such loss or expense  it shall  from time to time  notify
Undersigned of the amount determined in good faith by Bank (which  determination
shall be conclusive) to be necessary to indemnify Bank for such loss or expense.
Such amount shall be due and payable by Undersigned on demand.

11.  Records.  The unpaid  principal  amount of the Note,  the  unpaid  interest
accrued thereon,  the interest rate or rates applicable to such unpaid principal
amount,  the  duration  of such  applicability  and the date and  amount of each
payment or demand shall at all times be  ascertained  from the books and records
created by Bank, which shall be conclusive absent manifest error.

12. Notices.  All notices under Sections 7 or 9 of this  Supplement  shall be in
writing or by telephone  promptly  confirmed in writing,  and all such  writings
shall be sent by first-class,  first-class  express or certified mail or by hand
delivery,  in all cases with charges  prepaid.  All notices shall be sent to the
applicable  party at the  address  stated  on the  signature  page  hereof or in
accordance  with the last  unrevoked  written  direction  from such party to the
other  parties  hereto.  All  notices by  Undersigned  shall be  effective  when
received by Bank and all  notices by Bank shall be  effective  when  telephoned,
deposited in the mail or hand  delivered.  Written notices or  confirmations  by
Undersigned shall not be deemed records of Bank within the meaning of Section 11
of this Supplement  whether or not received by Bank. Bank may conclusively  rely
without  inquiry  on  any  notice  or  confirmation  purporting  to be  from  or
authorized by Undersigned.

13.      Definitions. As used in this Supplement:

           "ABS Rate" shall mean a per annum rate of interest  equal to the rate
of interest determined by Bank, in its sole discretion, from time to time, to be
its ABS Rate.  Such ABS Rate shall change from time to time as of the  effective
date of each  change in the ABS Rate as  determined  in the sole  discretion  of
Bank.  The ABS Rate may be greater or less than other  interest rates charged by
Bank to other  borrowers and is not solely based or dependent  upon the interest
rate which Bank may charge any particular borrower or class of borrowers.

           "As-Offered  Rate Option" shall mean a rate per annum offered by Bank
in its sole discretion to Undersigned from time to time for such Rate Period for
such Rate Segment as Bank may offer in its sole  discretion,  such interest rate
to remain fixed for the duration of such Rate Period.

           "Business  Day" shall mean any day on which Bank is open for business
at the location where the Note is payable.

           "LIBOR-Rate" for any day for any proposed or existing Rate Segment
corresponding  to a Rate Period shall mean the rate per annum determined by Bank
to be the rate per annum  obtained by  dividing  (the  resulting  quotient to be
rounded upward to the nearest 1/100 of 1%) (A) the rate of interest (which shall
be the same for each day in such Rate Period) estimated in good faith by Bank in
accordance with its usual procedures (which  determination  shall be conclusive)
to be the average of the rates per annum for deposits in United  States  dollars
offered  to  major  money  center  banks  in  the  London  interbank  market  at
approximately  11:00 a.m.,  London time,  two London  Business Days prior to the
first day of such Rate Period for  delivery on the first day of such Rate Period
in amounts  comparable to such Rate Segment (or, if there are no such comparable
amounts  actively  traded,  the  smallest  amounts  actively  traded) and having
maturities  comparable  to such Rate Period by (B) a number  equal to 1.00 minus
the LIBOR-Rate Reserve Percentage for such day.

            The "LIBOR-Rate" may also be expressed by the following formula:
                 (average of rates offered to major )
                 (money banks in the London inter-  )
                 (bank market estimated by the Bank )

          LIBOR-Rate = (subsection (A)(1)                  I
                         (1-00 - LIBOR-Rate Reserve Percentage]
           "LIBOR-Rate Reserve Percentage" for any day shall mean the percentage
(rounded upward to the nearest 1/100 of 1%), as determined in good faith by Bank
(which  determination shall  be  conclusive)  as  representing  for such day the
maximum   effective   reserve   requirement    (including   without   limitation
supplemental,  marginal  and  emergency  requirements)  for member  banks of the
Federal Reserve System with respect to eurocurrency  funding (currently referred
to as  "Euro-currency  liabilities")  of any maturity.  Each LIBOR-Rate shall be
adjusted  automatically as of the effective date of any change in the LIBOR-Rate
Reserve Percentage.

           "London  Business  Day" shall mean a day for  dealing in  deposits in
United States dollars by and among banks in the London interbank market.

           "Portion":  "Prime  Rate  Portion shall mean at any time the part,
including the whole, of the unpaid principal amount of the Note bearing interest
at such time  under  the  Prime  Rate  Option  or in  accordance  with the first
sentence of Section 5 of this  Supplement.  "ABS Rate Portion" shall mean at any
time the part,  including the whole, of the unpaid  principal amount of the Note
bearing  interest at such time under the ABS Rate Option or in  accordance  with
the first  sentence  of Section 5 of this  Supplement.  "LIBOR-Rate  Portion" or
"As-Offered Rate Portion" shall mean at  any time the part, including the whole,
of the unpaid  principal  amount of the Note bearing interest at such time under
the  LIBOR-Rate  Option or  As-Offered  Rate Portion as the case may be, or at a
rate  determined by reference to the LIBOR-Rate  Option pursuant to Section 5 of
this Supplement.

           "Prime Rate" shall mean the interest  rate per annum  announced  from
time to time by Banks as its Prime  Rate.  The Prime Rate may be greater or less
than other interest  rates charged by Bank to other  borrowers and is not solely
based or dependent  upon the interest rate which Bank may charge any  particular
borrower or class of borrowers.

           "Rate Segment" of the  LIBOR-Rate  Portion at any time shall mean the
entire  principal  amount  of such  Portion  to  which  at such  time  there  is
applicable a particular Rate Period  beginning on a particular day and ending on
another particular day. (By definition, each Portion is at all times composed of
an integral number of discrete Rate Segments, each corresponding to a particular
Rate  Period,  and the sum of the  principal  amounts of all Rate  Segments of a
particular  Portion at any time equals the  principal  amount of such Portion at
such time).

"Standard  Notice"  shall mean an  irrevocable  notice  provided  to the Bank on
Business Day which is

(i) at least one Business Day in advance in the case of selection of, conversion
to or renewal of the Prime Rate Option or prepayment of any Prime Rate Portion;

(ii) at least one  Business  Day in  advance  in the case of,  conversion  to or
renewal of the ABS Rate Option or prepayment of any ABS Portion:

(iii) at least two London  Business Days in advance in the case of selection of,
conversion  to or  renewal  of  the  LIBOR-Rate  Option  or  prepayment  of  any
LIBOR-Rate Option or prepayment of any LIBOR-Rate Portion, and

(iv)  at  least  one  Business  Day in  advance  in the  case of  selection  of,
conversion  to or renewal of the  As-Offered  Rate Option or  Prepayment  of any
As-Offered Rate Portion.

Standard  Notice must be provided no later than 1:00  o'clock  p.m.,  Pittsburgh
time, on the last day permitted for such notice.


Witness the due execution  hereof intending to be legally bound this 30th day of
December, 1997.

Attest:
/s/ Joseph E. Zavacky
Controller & Assistant Secretary

C-COR ELECTRONICS, INC.
By:
/s/ Chris A. Miller
Title: Vice President - Finance
Address for Notices to Undersigned:
60 Decibel Road
State College, PA    16801,

MELLON BANK, N.A.
By: Milton S. Hefft
Address for Notices to Bank:
Mellon Bank N.A.
Attn: Middle Market Banking
P.O. Box 1010
Harrisburg, PA 17108