Amendment Six To Credit Agreement


         THIS AMENDMENT SIX is dated as of May 1, 1999 and is made in respect of
the Credit  Agreement  dated as of July 12,  1996 and as  amended  and in effect
immediately  prior to the date hereof (the "Credit  Agreement") by and among PSC
SCANNING,  INC., a Delaware  corporation  formerly known as  SpectraScan,  Inc.,
which is the successor by merger to PSC Acquisition, Inc., (the "Borrower"), PSC
INC.  ("PSC"),  the financial  institutions  party to the Credit  Agreement (the
"Lender  Parties"),  FLEET NATIONAL BANK  (formerly  known as Fleet Bank) as the
"Initial  Issuing Bank", and FLEET NATIONAL BANK, as  administrative  agent (the
"Administrative Agent") under the Credit Agreement.

                            Statement of the Premises

         The Borrower, PSC, the Lender Parties, the Initial Issuing Bank and the
Administrative  Agent  previously  entered  into  the  Credit  Agreement,  First
Amendment to Credit Agreement dated as of September 27, 1996,  Amendment Two and
Waiver to Credit  Agreement dated as of July 4, 1997,  Amendment Three to Credit
Agreement  (With Consent) dated as of August 13, 1997,  Amendment Four to Credit
Agreement  dated as of April 8, 1998,  and Amendment Five and Consent and Waiver
to Credit Agreement dated as of March 1, 1999 ("Amendment  Five").  The Borrower
has requested  that the Lender  Parties  amend certain  provisions in the Credit
Agreement  to  reflect  the  accounting  treatment  of the  sale  and  leaseback
transaction  which was consented to by the Lender Parties under  Amendment Five,
and the Lender Parties are willing to do so.

                           Statement of Consideration

         Accordingly,  in consideration of the premises, and under the authority
of Section  5-1103 of the New York General  Obligations  Law, the parties hereto
agree as follows.

                                    Agreement

1. Defined Terms. The terms "this Agreement", "hereunder" and similar references
in the  Credit  Agreement  shall be deemed to refer to the Credit  Agreement  as
amended hereby.  Capitalized  terms used and not otherwise  defined herein shall
have the meanings ascribed to such terms in the Credit Agreement.

2.  Amendment.  Effective  as of May 1,  1999,  the Credit  Agreement  is hereby
amended as follows:

         2.1  Section  1.01 of the  Credit  Agreement  is  amended by adding the
definitions of "Excluded  Leaseback Gain", "1999 Sale Leaseback  Prepayment" and
"1999 Sale Leaseback Transaction", as follows:
<PAGE>

                           "Excluded  Leaseback  Gain"  means all gain  (gross -
                  before tax) resulting from the 1999 Sale Leaseback Transaction
                  or any  termination  of the lease  thereunder if (and only if)
                  such gain is more than $50,000 during any period  comprised of
                  four, full,  consecutive  quarter-annual  fiscal periods taken
                  together as one accounting period.

                           "1999 Sale Leaseback Prepayment" means the prepayment
                  of any Borrowing pursuant to Section 2.06(b)(ii) of the Credit
                  Agreement by reason of the 1999 Sale Leaseback Transaction.

                           "1999 Sale Leaseback  Transaction" means the sale and
                  leaseback transaction whereby certain of the facilities of the
                  Borrower  located  in  Eugene,  Oregon  shall be sold to Carey
                  Diversified LLC or one of its affiliates or assigns and leased
                  back to the Borrower on  substantially  the terms set forth in
                  the letter dated February 12, 1999 issued by Carey Diversified
                  LLC to the Borrower.

         2.2 Section  1.01 of the Credit  Agreement  is amended by changing  the
definitions  of  "Adjusted  EBITDA" and  "EBITDA"  to read in their  entirety as
follows:

                           "Adjusted  EBITDA"  means,  for any period,  the sum,
                  determined on a Consolidated  basis, of (a) net income (or net
                  loss) plus: (i) the Second  Quarter `97 Charge,  less (ii) for
                  each fiscal quarter through the fiscal quarter ending December
                  31,  1998,  that  portion  of the  Second  Quarter  `97 Charge
                  actually paid during such period,  less (iii) any gain arising
                  from a reversal of the Second Quarter `97 Charge, plus (iv) on
                  the fiscal  quarter end date of December  31,  1998,  the cash
                  balance of the Second  Quarter `97 Charge  which the  Borrower
                  has not yet paid in cash but which  the  Borrower  expects  to
                  incur,  (b)  interest  expense,  (c) income tax  expense,  (d)
                  depreciation expense and (e) amortization expense in each case
                  of PSC and its  Subsidiaries,  determined in  accordance  with
                  GAAP for such period,  less,  however,  the Excluded Leaseback
                  Gain, if any, accruing during such period.

                           "EBITDA" means , for any period, the sum,  determined
                  on a Consolidated  basis, of (a) net income (or net loss), (b)
                  interest  expense,  (c) income tax expense,  (d)  depreciation
                  expense and (e)  amortization  expense in each case of PSC and
                  its Subsidiaries,  determined in accordance with GAAP for such
                  period,  excluding  (i) in the case of the  Fiscal  Quarter in
                  which  the  consummation  of  the  Acquisition   occurs,   any
                  restructuring  charge  taken by PSC and its  Subsidiaries,  in
                  respect of the  Acquisition,  and (ii) the Excluded  Leaseback
                  Gain, if any, accruing during such period.

         2.3 Subclause  (y) of clause (ii) of Subsection  (a) of Section 5.04 of
the Credit Agreement, is amended to read in its entirety as follows:

                  (y)  principal  amounts of all Funded  Debt  payable,  in each
                  case,  by  PSC  and  its  Subsidiaries   during  such  period,
                  excluding the 1999 Sale Leaseback Prepayment and excluding all
                  payments or  prepayments  of any Borrowing with the Stock Sale
                  Proceeds other than (and not excluding)  payments scheduled to
                  be due and payable  during such  period,  if any  (without the
                  application of Section 2.06(b)(ii)),
<PAGE>

3. Effect on the Credit  Agreement.  Except as specifically  amended above,  the
Credit  Agreement  shall remain in full force and effect and is hereby  ratified
and confirmed.  The Borrower and PSC each  acknowledge and agree that the Credit
Agreement (as amended by this  Amendment)  and each other Loan Document to which
each is a party is in full force and effect, that its Obligations thereunder and
under this Amendment are its legal,  valid and binding  obligations  enforceable
against  it in  accordance  with the terms  thereof  and  hereof,  and it has no
defense,  whether legal or equitable,  setoff or counterclaim to the payment and
performance of such Obligations.

4.  Execution in  Counterparts  and  Effectiveness.  This  Amendment  Six may be
executed in any number of  counterparts  and by the different  parties hereto on
separate counterparts,  each of which shall be deemed to be an original, and all
of  which  taken  together  shall  constitute  one and the same  Amendment  Six,
regardless  of whether or not the  execution by all parties  shall appear on any
single counterpart.  Delivery of an executed  counterpart of a signature page to
this  Amendment Six by  telecopier  shall be effective as delivery of a manually
executed  counterpart  of this  Amendment  Six.  This  Amendment Six will become
effective when the Administrative Agent shall have received counterparts of this
Amendment Six which,  when taken together,  bear the signatures of the Borrower,
PSC, the Administrative Agent and the Required Lenders.

5.  Applicable  Law.  Pursuant  to  Section  5-1401  of  the  New  York  General
Obligations  Law, the laws of the State of New York shall  govern the  validity,
construction,  enforcement and interpretation of this Amendment Five and Consent
and Waiver in whole without regard to any rules of conflicts-of-laws  that would
require the application of the laws of any jurisdiction  other than the State of
New York.

6. Headings.  The headings of this Amendment Five and Consent and Waiver are for
the  purposes  of  reference  only and shall not limit or  otherwise  affect the
meanings hereof.

         IN WITNESS  WHEREOF,  the parties  hereto have caused a counterpart  of
this Amendment Five and Consent and Waiver to be executed and delivered by their
respective representatives thereunto duly authorized, as of the date first above
written.


PSC INC.                                  PSC SCANNING, INC.

By:                                       By:
Title:   Vice President, Chief Financial  Title:   Vice President and Chief
         Officer & Treasurer                       Financial Officer


FLEET NATIONAL BANK, as Initial            FLEET NATIONAL BANK, as
Issuing Bank                               Administrative Agent


By:                                        By:
Title:                                     Title:


FLEET NATIONAL BANK                        FIRST UNION NATIONAL BANK

By:                                        By:
Title:                                     Title:


MANUFACTURERS & TRADERS                    KEY BANK NATIONAL
TRUST COMPANY                              ASSOCIATION

By:                                        By:
Title:                                     Title:


THE CHASE MANHATTAN BANK

By:

Title: