Exhibit 10.21

                           FASTCALL PURCHASE AGREEMENT

                                DECEMBER 31, 1997

                          SPANLINK COMMUNICATIONS, INC.
                                      BUYER

                                       AND

                              AURORA SYSTEMS, INC.
                                     SELLER


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                                                 TABLE OF CONTENTS

ARTICLE 1.

         PURCHASE OF FASTCALL; ASSUMPTION OF LIABILITIES                                         1
         1.1      Purchase of Assets from Seller                                                 1
         1.2      Royalty-Free License                                                           2
         1.3      Sales, Use and Deed Taxes                                                      2
         1.4      Assumption of Liabilities                                                      3
         1.5      Warranty Obligations                                                           3

ARTICLE 2.

         PURCHASE PRICE AND PAYMENT                                                              3
         2.1      Purchase Price                                                                 3
         2.2      Payment of Purchase Price                                                      4

ARTICLE 3.

         REPRESENTATIONS AND WARRANTIES OF SELLER                                                5
         3.1      Organization                                                                   5
         3.2      Qualification                                                                  5
         3.3      Financial Information                                                          6
         3.4      Tax Reports, Returns and Payment                                               6
         3.5      Title and Sufficiency of Assets                                                6
         3.6      Trademarks                                                                     6
         3.7      Patents                                                                        6
         3.8      Licenses and Permits                                                           6
         3.9      Agreements, Contracts and Commitments                                          7
         3.10     Change In Customers                                                            7
         3.11     Product Warranty Claims                                                        7
         3.12     Litigation, Adverse Claims and Related Matters                                 7
         3.13     Laws and Regulations                                                           7
         3.14     Breaches of Contracts; Required Consents                                       7
         3.15     Binding Obligation                                                             8
         3.16     Commissions or Finder's Fees                                                   8
         3.17     Employee Agreements                                                            8
         3.18     Completeness of Disclosure                                                     8

ARTICLE 4.

         REPRESENTATIONS AND WARRANTIES OF BUYER                                                 8
         4.1      Organization                                                                   8
         4.2      Qualification                                                                  8
         4.3      Corporate Authority                                                            8
         4.4      Financial Information                                                          9
         4.5      Licenses and Permits                                                           9
         4.6      Litigation, Adverse Claims and Related Matters                                 9
         4.7      FastCall Resources                                                             9
         4.8      Breaches of Contracts; Required Consents                                       9
         4.9      Binding Obligation                                                             9
         4.10     Commissions or Finder's Fees                                                   9
         4.11     Completeness of Disclosure                                                     10

ARTICLE 5.

         CONDUCT OF BUSINESS AND TRANSACTIONS PRIOR TO CLOSING                                   10
         5.1      Access to Information                                                          10
         5.2      Restrictions in Operation of the Business                                      10
         5.3      No Solicitation of Other Offers                                                10
         5.4      Confidentiality Agreement                                                      11
         5.5      Offer of Employment                                                            13
         5.6      Cash Payment                                                                   13

ARTICLE 6.

         CONDITIONS OF CLOSING; ABANDONMENT OF TRANSACTION                                       13
         6.1      Conditions to Obligations of Buyer to Proceed on the Closing Date              13
         6.2      Conditions to Obligation of Seller to Proceed on the Closing Date              15
         6.3      Termination of Agreement                                                       16
         6.4      Consequences of Termination                                                    16

ARTICLE 7.

         CLOSING                                                                                 17
         7.1      Closing                                                                        17
         7.2      Documents to be Delivered by Seller                                            17
         7.3      Documents Delivered by Buyer                                                   17

ARTICLE 8.

         POST CLOSING OBLIGATIONS                                                                18
         8.1      Covenant Not to Compete                                                        18
         8.2      Further Documents and Assurances                                               18
         8.3      Consulting                                                                     18
         8.4      Accounts Receivable                                                            19
         8.5      Un-Invoiced Sales                                                              19
         8.6      Fleet Capital Corporation Releases                                             19

ARTICLE 9.

         INDEMNIFICATION                                                                         19
         9.1      Indemnification by Seller                                                      19
         9.2      Seller's Limitation of Liability                                               20
         9.3      Indemnification by Buyer                                                       20
         9.4      Buyer's Limitation of Liability                                                20
         9.5      Limitations on Indemnification                                                 20
         9.6      Third Party Claims                                                             21

ARTICLE 10.

         GENERAL                                                                                 21
         10.1     Assignment                                                                     21
         10.2     Counterparts                                                                   21
         10.3     Exhibits                                                                       22
         10.4     Notices                                                                        22
         10.5     Successors and Assigns                                                         22
         10.6     Expenses                                                                       22
         10.7     Entire Agreement                                                               22
         10.8     Modification and Waiver                                                        22
         10.9     Publicity                                                                      22
         10.10    Governing Law                                                                  22
         10.11    Knowledge                                                                      22
         10.12    Benefit                                                                        23
         10.13    Comdial Corporation                                                            23


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                                LIST OF EXHIBITS

Exhibit 1.1(a)             List of Names, Assumed Names, Tradenames and Trademarks of Seller
Exhibit 1.1(b)             List of Patents
Exhibit 1.1(d)             Accounts Receivable
Exhibit 1.1(c)             Computer Programs and Software
Exhibit 1.1(f)             FastCall Licenses and Permits
Exhibit 1.1(g)             FastCall Contracts and Customers
Exhibit 3.3                Seller Financial Information
Exhibit 3.4                Tax Reports, Returns and Payments
Exhibit 3.5                Seller Encumbrances on Assets
Exhibit 3.8                Consents Required to Assign Licenses
Exhibit 3.14               Other Required Consents
Exhibit 4.4                Buyer Financial Information
Exhibit 5.5                Seller Assisted Signing Bonus
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FASTCALL  PURCHASE  AGREEMENT


DATE:             December 31, 1997

PARTIES: Spanlink Communications, Inc.
                  7125 Northland Terrace
                  Brooklyn Park, MN 55428                              ("Buyer")

                  Aurora Systems, Inc.
                  33 Nagog Park
                  Acton, MA 01720                                     ("Seller")


RECITALS:

         A.  Seller has  developed  and is  distributing  and selling a computer
telephone  integration  product known as FastCall  ("FastCall") which provides a
personal computer with Windows desktop-based screen pops, and an NT server-based
version of FastCall which provides call functionality, known as FastCall Central
("FastCall  Central").  FastCall and FastCall Central are sometimes  referred to
collectively as the "FastCall Products."

         B. The parties  mutually desire that Seller shall sell to Buyer and the
Buyer shall purchase from the Seller the FastCall  Products and related business
assets,  upon  the  terms  and  subject  to the  conditions  set  forth  in this
Agreement.


AGREEMENT:

         In consideration of the mutual provisions, representations, warranties,
covenants and agreements contained herein, the parties hereto agree as follows:


                                   ARTICLE 1.

                 PURCHASE OF FASTCALL; ASSUMPTION OF LIABILITIES

         1.1 Purchase of Assets from Seller: Subject to the terms and conditions
hereof,  Seller agrees on the Closing Date (as  hereinafter  defined) to assign,
sell, transfer,  convey and deliver or license to Buyer, and Buyer agrees on the
Closing Date to purchase or otherwise acquire from Seller, the FastCall Products
and all of the intangible personal property,  business records,  customer lists,
contract  rights  and  goodwill  of Seller  related  to the  FastCall  Products,
wherever  the same may be located  (collectively  referred to as the  "Purchased
Assets"), including, without limitation, the following:

                  (a) All names and assumed  names under which Seller  develops,
         markets and sells the FastCall Products,  all tradenames,  trademark or
         service mark  registrations  and  applications,  common law trademarks,
         including but not limited to those  identified on Exhibit  hereto,  and
         all goodwill associated therewith (the "FastCall Trademarks");

                  (b) Subject to the provisions of Section hereof,  all domestic
         and  foreign  letters  patent,  patent  applications,  and  patent  and
         know-how  licenses,  including  but not limited to those  identified on
         Exhibit hereto but excluding the license  agreement  between Seller and
         Syntellect  Technology  Corp.  effective  as of February  12, 1996 (the
         "Syntellect  License")  ("Patents"),  together  with copies of Seller's
         legal  files  and other  background  information  relating  to any such
         Patents;

                  (c) All technology, know-how, trade secrets, designs, computer
         source code,  copyrights  (including all registrations and applications
         therefor),  related to the FastCall Products, including all documentary
         evidence thereof, and the computer programs and software (the "Computer
         Programs") listed on Exhibit (the "FastCall Technology");

                  (d) All  rights  to  accounts  receivable  from  sales  of the
         FastCall Products invoiced in the calendar quarter  commencing  October
         1, 1997 and ending December 31, 1997 (the "Fourth Quarter"),  which are
         in excess of One  Hundred  Ninety  Thousand  Two  Hundred  Fifty  Three
         Dollars   and  Fifty  Cents   ($190,253.50)   (the   "Excess   Accounts
         Receivable"),  but no rights to the other accounts receivable of Seller
         whether or not invoiced in the Fourth Quarter.

                  (e) All rights to payment for sales of the  FastCall  Products
         in the Fourth  Quarter  which have not been invoiced to customers as of
         the Closing (the "Un-Invoiced  Sales"),  including the un-invoiced sale
         to Lucent Technologies (NJ) identified on Exhibit 1.1(d).

                  (f)  All  permits,   licensing  approvals  and  notifications,
         governmental  or  otherwise,  relating to the  FastCall  Products  (the
         "FastCall  Licenses and Permits"),  including those listed on Exhibit ;
         and

                  (g) All  contract  rights  (except any real estate  leases and
         personal  property  leases)  relating  to the  FastCall  Products  (the
         "FastCall Contracts"), including those rights pursuant to the contracts
         described in Exhibit .

         1.2 Royalty-Free  License. At the Closing,  Buyer shall grant to Seller
and Comdial Corporation a royalty-free  non-exclusive license to use the Patents
for any  purposes  that do not  conflict  with the  express  provisions  of this
Agreement.

         1.3 Sales, Use and Deed Taxes.  Seller shall be responsible for payment
of any sales,  use or deed taxes  assessable with respect to the transfer of the
Purchased Assets contemplated herein.

         1.4 Assumption of  Liabilities.  Buyer agrees to assume the obligations
of Seller which arise from and after the Closing under the FastCall Licenses and
Permits,  including those listed on Exhibit , and under the FastCall  Contracts,
including those listed on Exhibit .

         1.5 Warranty  Obligations.  Buyer agrees to assume the remainder of the
Seller's existing warranty  obligations arising in the normal course of Seller's
business with respect to the FastCall Products sold by it prior to the Closing.


                                    ARTICLE 2

                           PURCHASE PRICE AND PAYMENT

         2.1  Purchase  Price.  The  purchase  price  for the  Purchased  Assets
("Purchase  Price") shall be paid as royalties  computed with reference to sales
revenue  invoiced  by Buyer  from the sale,  distribution  or  licensing  of the
FastCall Products and all enhancements, upgrades, modifications and improvements
thereto or derivatives thereof and including  replacement  products developed by
Buyer (collectively the "Royalty Products"), and shall be determined as follows:

                  (a) Calculation of Purchase  Price.  Buyer shall pay to Seller
         as  and  for  the  actual   Purchase   Price  an  amount  of  royalties
         ("Royalties")  based on sales  revenue  invoiced by Buyer from sales of
         the Royalty Products ("FastCall Revenues"). The Purchase Price shall be
         equal  to  twenty-five  percent  (25%)  of all  FastCall  Revenues  (i)
         invoiced by Buyer during the period  commencing on the Closing Date and
         ending  December 31, 2000,  and (ii) invoiced or received by Buyer from
         Excess  Accounts   Receivable  pursuant  to  Section  1.1(d)  and  from
         Un-Invoiced  Sales pursuant to Section , plus fifteen  percent (15%) of
         all FastCall Revenues invoiced by Buyer during the period commencing on
         January 1, 2001 and ending December 31, 2002.

                  (b) Minimum and Maximum  Limits of Purchase  Price.  The total
         Purchase  Price  shall be no less  than Six  Hundred  Thousand  Dollars
         ($600,000)  (the  "Minimum  Purchase  Price")  and no greater  than One
         Million  One  Hundred  Thousand  Dollars   ($1,100,000)  (the  "Maximum
         Purchase Price").

                  (c) Allocation of Sales Revenue.  The parties  acknowledge and
         agree that the FastCall  Products may be integrated with other products
         ("Replacement  Products")  sold by Buyer in the  generation of FastCall
         Revenues.  In such event Buyer shall determine the portion of the total
         sales revenue from each Replacement  Product that is properly allocable
         to the FastCall  Products  and shall  provide  Seller with  information
         regarding the amount and method of such allocation.

                           (i)  Except  in the case set  forth  in  clause  (ii)
                  below,  the  revenue  from  each  such   Replacement   Product
                  allocated to the FastCall  Products (the "Allocated  Revenue")
                  shall be at least eighty  percent (80%) of the lowest price at
                  which Buyer invoiced sales of the FastCall Products on a stand
                  alone  basis  during the twelve  (12) month  period (the "Look
                  Back  Period")  preceding  the sale of each  such  Replacement
                  Product.  In the  event  there  are no sales  of the  FastCall
                  Products  during the relevant Look Back Period,  the Allocated
                  Revenue for the sale of  Replacement  Products shall be deemed
                  to be an amount equal to the last calculated Allocated Revenue
                  immediately preceding the Look Back Period.

                           (ii) In  case  the  value  of the  FastCall  Products
                  integrated  into a  Replacement  Product  is less  than  forty
                  percent  (40%) of the value of the  Replacement  Product,  the
                  Allocated  Revenue  with respect to such  Replacement  Product
                  shall be at least forty  percent  (40%) of the lowest price at
                  which Buyer invoiced sales of the FastCall Products on a stand
                  alone basis  during the Look Back  Period.  In the event there
                  are no sales of the FastCall Products during the relevant Look
                  Back Period, the Allocated Revenue for the sale of Replacement
                  Products  shall be deemed  to be an  amount  equal to the last
                  calculated  Allocated Revenue  immediately  preceding the Look
                  Back Period.

                           (iii)  Nothing  herein  shall give  Seller any right,
                  express or implied,  to set sales prices or royalty rates with
                  respect to the  Royalty  Products,  all of such  rights  being
                  reserved to Buyer, in Buyer's sole discretion.

                  (d) In determining  the FastCall  Revenue during each calendar
         quarter,  Buyer shall be entitled to reduce such revenue by returns and
         sales  allowances  that are  recorded on Buyer's  books or records as a
         reduction of sales during such calendar  quarter in the ordinary course
         of  business  and in  accordance  with  generally  accepted  accounting
         principles,  but only to the extent  previously  included  in  FastCall
         Revenues on which Royalties have been paid to the Seller.

2.2     Payment of Purchase Price.  The Purchase Price shall be paid as follows:

                  (a) Cash Payment. Buyer shall deliver to Seller at the Closing
         an advance  payment to be applied to the Purchase  Price of One Hundred
         Thousand Dollars ($100,000), less the amount of any payments or credits
         due to Buyer from  Seller at the  Closing,  by wire  transfer to a bank
         account designated by Seller.

                  (b) Payment of Balance of the Purchase  Price.  The balance of
         the Purchase Price remaining  after the credit of One Hundred  Thousand
         Dollars  ($100,000)  arising out of the cash payment  made  pursuant to
         Section  2.2(a)  shall be paid in quarterly  installments,  paid within
         thirty  (30)  days  after  the end of each  calendar  quarter  in which
         FastCall Revenues were invoiced, in accordance with the following:

                           (i) The  first of such  payments  shall be made  with
                  respect to the calendar  quarter ending March 31, 1998 and the
                  last of  such  payments  shall  be made  with  respect  to the
                  calendar  quarter  ending  December  31,  2002  (the  "Payment
                  Period").

                           (ii) Each quarterly payment shall be in the amount of
                  the specified  percentage of the aggregate  FastCall  Revenues
                  invoiced in such calendar  quarter,  except that the credit of
                  One Hundred  Thousand  Dollars  ($100,000)  arising out of the
                  cash payment made pursuant to Section  2.2(a) shall be applied
                  to the payment of that portion of the Purchase  Price  between
                  Five  Hundred  Thousand  Dollars  ($500,000)  and Six  Hundred
                  Thousand Dollars ($600,000).

                           (iii)  In  the  event  the  aggregate  amount  of the
                  payments  made towards the  Purchase  Price during the Payment
                  Period (the "Total  Payment  Amount") is less than the Minimum
                  Purchase  Price,  the Buyer will pay to Seller promptly at the
                  end of the Payment  Period an amount  equal to the  difference
                  between  the  Minimum  Purchase  Price and the  Total  Payment
                  Amount.

                           (iv) The Payment  Period  shall  terminate  upon full
payment of the Maximum Purchase Price.

                  (c)  Records  Inspection.  Seller  shall  have the  right,  at
         reasonable  times and upon  reasonable  notice,  for its  employees  or
         agents to inspect the records of the Buyer with  respect to the Royalty
         Products, for the purpose of verifying any allocations of sales revenue
         made by the Buyer  and the  determinations  of  FastCall  Revenues  and
         Royalties.


                                   ARTICLE 3.

                    REPRESENTATIONS AND WARRANTIES OF SELLER

         Seller makes the following representations and warranties to Buyer with
the intention that Buyer may rely upon the same and  acknowledges  that the same
shall be true on the date hereof and as of the  Closing  Date (as if made at the
Closing)  and shall  survive  the  Closing of this  transaction  for a period of
twelve (12) months after the Closing Date.

         3.1  Organization.  Seller is a  corporation  duly  organized,  validly
existing and in good standing  under the laws of the State of Delaware,  has all
requisite  power and authority,  corporate and otherwise,  to own its properties
and assets and to conduct its business as it is now conducted.

         3.2  Qualification.  Seller is  qualified to do business and is in good
standing  as a  foreign  corporation  in all  states in which  qualification  is
required  by the nature of its  business  and in which the failure to so qualify
and be in good standing  would have a material  adverse  effect on the Purchased
Assets.

         3.3 Financial Information.  To the best knowledge of Seller, Seller has
furnished  Buyer with the  financial  information  attached  hereto as Exhibit ,
which is true and  complete.  In  addition,  Seller  agrees to  furnish to Buyer
within  sixty  (60)  days of  Closing  audited  financial  statements  of Aurora
Systems,  Inc.  for  periods  required  by  the  rules  and  regulations  of the
Securities  and Exchange  Commission  (the "SEC") or as  reasonably  required by
Buyer's independent  certified public accountants based on their  interpretation
of the SEC requirements.  The cost to provide such audited financial  statements
or other financial information will be divided equally between Buyer and Seller.

         3.4 Tax Reports,  Returns and Payment. To the best knowledge of Seller,
Seller (or Comdial  Corporation on behalf of Seller,  through  consolidated  tax
returns) has  accurately  prepared  and timely filed all federal and  applicable
state,  local,  and foreign tax or assessment  reports and returns of every kind
required to be filed by Seller with relation to its business, including, without
limitation,  income tax, sales and use tax, real estate tax,  personal  property
tax and  unemployment  tax,  and has  duly  paid all  taxes  and  other  charges
(including  interest  and  penalties)  due to or claimed to be due by any taxing
authorities,  except as disclosed in Exhibit  attached  hereto.  Where required,
timely estimated  payments or installment  payments of tax liabilities have been
made to all governmental  agencies in amounts  sufficient to avoid  underpayment
penalties or late payment penalties applicable thereto.

         3.5  Title  and  Sufficiency  of  Assets.  Seller  holds  title  to the
Purchased Assets free and clear of all liens, encumbrances,  licenses or leases,
except for the liens and security  interests  (the "Fleet  Liens")  disclosed in
Exhibit . The Purchased Assets are sufficient for Buyer to market, sell, service
and support the FastCall Products as marketed and sold at the Closing, except to
the extent, if any, the Syntellect License is required or necessary to make this
representation true and correct.

         3.6  Trademarks.  Seller  has good title to the  assumed  names and the
FastCall  Trademarks  listed  on  Exhibit  , free  and  clear of all  liens  and
encumbrances,  except as disclosed in Exhibit . Such FastCall Trademarks are not
licensed to or licensed from any other person or entity.

         3.7  Patents.  Seller has good title to the  Patents  listed on Exhibit
hereto,  free and  clear of all liens  and  encumbrances  except as set forth on
Exhibit .

         3.8 Licenses  and  Permits.  Seller  possesses  all permits,  licenses,
approvals and  notifications,  governmental  or otherwise,  the absence of which
would have a material adverse effect on the Purchased Assets. Buyer acknowledges
that it is not taking an assignment of the Syntellect  License,  which is one of
the licenses that Seller possesses. Seller makes no representation as to whether
the absence of the  Syntellect  License would have a material  adverse effect on
the Purchased Assets.  Except as disclosed on Exhibit , all of such licenses and
permits are freely  assignable and transferable to Buyer at the Closing and will
continue to be in full force and effect after such transfer.

         3.9  Agreements,  Contracts  and  Commitments.  Except as  disclosed on
Exhibit or on other Exhibits attached hereto,  Seller is not a party to or bound
by any written agreement  relating to the Purchased Assets, nor does Seller have
any knowledge of any claims made by parties to the FastCall Contracts.

         3.10 Change In Customers.  To Seller's best  knowledge,  no significant
customer,  including  but not  limited  to those  customers  listed in Exhibit ,
intends to cease doing  business with Seller or  materially  alter the amount of
business with Seller.

         3.11  Product  Warranty  Claims.   The  FastCall   Products  have  been
merchantable  and free from material  defects in material or workmanship for the
term and under the conditions  set forth in Seller's  standard  written  limited
product warranty for its FastCall  Products.  Except for product warranty claims
in the ordinary  course of business,  during the last three (3) years Seller has
not received any claims based upon an alleged breach of product warranty arising
from Seller's sale of its FastCall Products (hereafter  collectively referred to
as "Product Warranty Claims").  Seller has no reasonable grounds to believe that
future Product  Warranty Claims with respect its FastCall  Products prior to the
Closing  Date will be  different  from  Seller's  past  experience  with respect
thereto as set forth herein.

         3.12  Litigation,  Adverse  Claims  and  Related  Matters.  There is no
pending litigation (nor, to Seller's knowledge, any threatened litigation or any
claim which may lead to a threat of litigation),  proceeding,  or  investigation
(including any environmental,  building or safety investigation) relating to any
material aspect of the Purchased  Assets,  nor is Seller subject to any existing
judgment,  order or decree  which would  prevent,  impede,  or make  illegal the
consummation of the  transactions  contemplated in this Agreement or which would
have a material adverse effect on the Purchased Assets.

         3.13 Laws and Regulations. Seller has complied, and is in compliance on
the Closing Date, with all applicable laws, statutes, orders, rules, regulations
and requirements  promulgated by governmental or other  authorities  relating to
the Purchased Assets,  the failure of which would have a material adverse effect
on the  Purchased  Assets.  Seller  has not  received  any notice of any sort of
alleged violation of any such statute, order, rule, regulation or requirement.

         3.14 Breaches of Contracts;  Required  Consents.  Neither the execution
and delivery of this  Agreement  by Seller,  nor  compliance  by Seller with the
terms and  provisions  of this  Agreement  will,  except as otherwise  disclosed
herein or in any Exhibit attached hereto:

                  (a)  Conflict  with or  result  in a breach  of (i) any of the
         terms,  conditions or provisions of the  Certificate of  Incorporation,
         Bylaws or other  governing  instruments  of Seller,  (ii) any judgment,
         order,  decree  or  ruling  to  which  Seller  is a  party,  (iii)  any
         injunction  of any court or  governmental  authority to which Seller is
         subject,  or (iv)  any  agreement,  contract  or  commitment  which  is
         material to the Purchased Assets; or

                  (b)  Except  as  disclosed  in  Exhibit  hereto,  require  the
         affirmative  consent or  approval  of any third  party,  the absence of
         which would have a material adverse effect on the Purchased Assets.

         3.15 Binding  Obligation.  This Agreement  constitutes the legal, valid
and binding obligation of Seller in accordance with the terms hereof. Seller has
all  requisite  corporate  power and  authority,  including  the approval of its
Shareholders  and  Board  of  Directors,  to  execute  perform,  carry  out  the
provisions of and consummate the transactions contemplated in this Agreement.

         3.16 Commissions or Finder's Fees. Seller has not engaged any broker or
finder in connection with the transaction contemplated herein.

         3.17 Employee  Agreements.  Seller has no knowledge that any current or
former employee of Seller has violated any confidentiality agreements.

         3.18   Completeness   of   Disclosure.   To  Seller's   knowledge,   no
representation  in this Article contains any untrue statement of a material fact
or omits to state any material fact the omission of which would be misleading.


                                   ARTICLE 4.

                     REPRESENTATIONS AND WARRANTIES OF BUYER

         Buyer makes the  following  representations  and  warranties to Seller,
with the intention that Seller may rely upon the same, and acknowledges that the
same shall be true as of the Closing  Date (as if made at the Closing) and shall
survive the Closing of this transaction for a period of twelve (12) months after
the Closing Date..

         4.1  Organization.  Buyer is a  corporation,  duly  organized,  validly
existing in good standing under the laws of the State of Minnesota,  and has all
requisite  power and authority,  corporate and otherwise,  to own its properties
and assets and conduct its business as it is now conducted.

         4.2  Qualification.  Buyer  is  qualified  to do  business  and is good
standing  as a  foreign  corporation  in all  states in which  qualification  is
required  by the nature of its  business  and in which the failure to so qualify
and be in good in standing would have a material adverse effect on its business.

         4.3 Corporate  Authority.  Buyer has all requisite power and authority,
including the approval of its Board of Directors, to execute, perform, carry out
the provisions in this Agreement.

         4.4  Financial  Information.   Buyer  has  furnished  Seller  with  the
financial information attached hereto as Exhibit , true and complete.

         4.5  Licenses  and  Permits.  Buyer  possesses,  or from and  after the
Closing Date will possess, all permits,  licenses,  approvals and notifications,
governmental  or otherwise,  the absence of which would have a material  adverse
effect on its business after  consummation of the  transactions  contemplated in
this Agreement.

         4.6 Litigation, Adverse Claims and Related Matters. There is no pending
litigation (nor, to Buyer's  knowledge,  any threatened  litigation or any claim
which  may  lead  to a  threat  of  litigation),  proceeding,  or  investigation
(including any environmental,  building or safety investigation) relating to any
material  aspect of  Buyer's  business,  nor is Buyer  subject  to any  existing
judgement,  order or decree  which would  prevent,  impede,  or make illegal the
consummation of the  transactions  contemplated in this Agreement or which would
have a material adverse effect on Buyer's business.

         4.7 FastCall  Resources.  Buyer has sufficient  resources to market and
sell the  Royalty  Products,  and will use all  reasonable  efforts  in light of
market  conditions  generally  prevailing from time to time to generate revenues
from the sale, distribution or licensing of Royalty Products.

         4.8 Breaches of Contracts; Required Consents. Neither the execution and
delivery of this Agreement by Buyer,  nor compliance by Buyer with the terms and
provisions of this Agreement, will:

                  (a)  Conflict  with or result in a breach  of:  (i) any of the
         terms,  conditions  or  provisions  of the  Articles of  Incorporation,
         Bylaws or other  governing  instruments  of Buyer,  (ii) any  judgment,
         order, decree or ruling to which Buyer is a party, (iii) any injunction
         of any court or governmental  authority to which it is subject, or (iv)
         any  agreement,  contract  or  commitment  which  is  material  to  the
         financial condition of Buyer; or

                  (b) Require the  affirmative  consent or approval of any third
         party.

         4.9 Binding Obligation. This Agreement constitutes the legal, valid and
binding  obligation of Buyer in accordance  with the terms hereof.  Buyer is not
subject to any charter, mortgage, lien, lease, agreement,  contract, instrument,
law, rule,  regulation,  order,  judgment or decree, or any other restriction of
any kind or character,  which would prevent the consummation of the transactions
contemplated in this Agreement.

         4.10  Commissions or Finder's Fees. Buyer has not engaged any broker or
finder in connection with the transactions contemplated herein.

         4.11  Completeness  of Disclosure.  No  representation  in this Article
contains any untrue  statement of a material fact or omits to state any material
fact the omission of which would be misleading.


                                    ARTICLE 5

              CONDUCT OF BUSINESS AND TRANSACTIONS PRIOR TO CLOSING

         5.1 Access to  Information.  During the  period  prior to the  Closing,
Seller shall give to Buyer and its attorneys,  accountants  or other  authorized
representatives,   full  access  to  all  of  the  property,  books,  contracts,
commitments  and records  relating to the Purchased  Assets and shall furnish to
Buyer during such period all such information concerning the Purchased Assets as
Buyer  reasonably  may request.  Buyer shall have the right to contact  Seller's
employees   regarding  the  Purchased  Assets  for  the  purposes  of  gathering
information   about  the   Purchased   Assets  and  of   discussing   employment
opportunities with Buyer.

         5.2  Restrictions in Operation of the Business.  Seller  represents and
covenants  that during the period from the date of this Agreement to the Closing
(except as Buyer otherwise has consented or may consent in writing):

                  (a) The Seller's  business will be conducted only in the usual
         and ordinary manner insofar as it relates to the Purchased Assets.

                  (b)  Seller  will  not  sell,  dispose,  transfer,  assign  or
         otherwise  remove any of the Purchased  Assets except  inventory in the
         ordinary course of business and at regular prices.

                  (c)  Seller  will  timely  pay and  discharge  all  bills  and
         monetary  obligations  and  timely  and  properly  perform  all  of its
         obligations and commitments under all existing contracts and agreements
         pertaining to the Purchased Assets, except as to amounts or obligations
         which Seller contests in good faith.

                  (d) Seller shall use its best efforts to preserve its business
         organization  and the Purchased  Assets and to keep  available to Buyer
         the  services  of  Seller's  present  employees,   and  not  to  impair
         relationships  with  suppliers,  customers and others  having  business
         relations with the Purchased Assets.

         5.3 No Solicitation of Other Offers.  Seller agrees that,  prior to the
Closing  Date or the  termination  of this  Agreement  pursuant to Section  6.3,
neither  Seller  nor  any  of  Seller's  representatives  will  enter  into  any
negotiations  with or solicit  any offer,  inquiry  or  proposal  from any other
person with respect to the sale or other acquisition of the Purchased Assets.

         5.4      Confidentiality Agreement.

                  (a) Definition of  Confidential  Information.  For purposes of
         this  Section,  "Confidential  Information"  means any  information  or
         compilation of information not generally known, which is proprietary to
         a  business,   and  includes,   without   limitation,   trade  secrets,
         inventions,  and  information  pertaining  to  development,  marketing,
         sales, accounting and licensing of the business' products and services,
         customer  information,  customer  lists,  and any customer  information
         contained in customer records,  working papers or correspondence  files
         and all financial  information,  including financial statements,  notes
         thereto and  information  contained  in federal and state tax  returns.
         Information shall be treated as Confidential  Information  irrespective
         of its  source  and  all  information  which  is  identified  as  being
         "confidential",  "trade  secret",  or is  identified or marked with any
         similar reference shall be presumed to be Confidential Information.

                  (b) Covenants by Parties.  Buyer, on the one hand, and Seller,
         on the other,  each agree and covenant with respect to all Confidential
         Information  of the  other  received  or  learned  by either of them as
         follows:

                           (i) It will treat as  confidential  all  Confidential
                  Information  made  available  to it or any  of its  employees,
                  agents or representatives;

                           (ii) It will  maintain the same in a secure place and
                  limit  access  to  the   Confidential   Information  to  those
                  employees,  agents and representatives to whom it is necessary
                  to disclose the Confidential Information in furtherance of the
                  transactions contemplated by this Agreement;

                           (iii)   It   and   its    employees,    agents    and
                  representatives  will not copy any  Confidential  Information,
                  disclose  any  Confidential  Information  to any  unauthorized
                  party,  or use any  Confidential  Information  for any purpose
                  including  competition with the other party or solicitation of
                  the other party's customers; and

                           (iv) It will take reasonable steps to insure that its
                  employees,  agents  or  representatives  who  have  access  to
                  Confidential  Information will maintain the confidentiality of
                  such information.

                  (c)      Applicability; Limitations.

                           (i) The  obligations  imposed by this  Section  shall
                  apply (x) to Buyer  forever with  respect to any  Confidential
                  Information  relating to the business or  operations of Seller
                  other than the  Purchased  Assets,  and until the Closing with
                  respect to the  Purchased  Assets or, if such Closing does not
                  occur,  forever with respect to the Purchased Assets,  and (y)
                  to Seller  forever with respect to the operations of Buyer and
                  forever with respect to the Purchased Assets after the Closing
                  except  in  connection  with  actions  expressly  provided  or
                  permitted  to  Seller  herein;  provided,  however,  that  the
                  obligations imposed by this Section 5.4 shall not apply to any
                  Confidential Information:

                                    (aa) which was known to the receiving  party
                                    prior to receipt from the disclosing party;

                                    (bb) which was  publicly  divulged  prior to
                                    receipt from the disclosing party;

                                    (cc)  which,  through  no act on the part of
                                    the  receiving  party,   thereafter  becomes
                                    publicly divulged;

                                    (dd) which was received in good faith by the
                                    receiving party from any third party without
                                    breach     of     any     obligations     of
                                    confidentiality; or

                                    (ee)  which  was   independently   developed
                                    (without   access   to   or   use   of   any
                                    Confidential Information of the other party)
                                    by an  employee  or agent  of the  receiving
                                    party   subsequent   to   receipt   of   the
                                    Confidential    Information    under    this
                                    Agreement.

                           (ii) The  obligations  imposed by this Section 5.4 on
                  Seller  shall not apply to the Comdial  Corporation  "Quick Q"
                  call  center  product,   including   enhancements,   upgrades,
                  modifications and improvements thereto or derivatives thereof,
                  and  including   replacement  products  developed  by  Comdial
                  Corporation.

                  (d)   Injunctive   Relief.   The   parties   agree   that  the
         non-breaching  party would not have an  adequate  remedy at law for any
         breach or  nonperformance of the terms of this Section 5.4 by the other
         party or any of its employees, agents and representatives and that this
         Agreement,   therefore,   may  be   enforced   in  equity  by  specific
         performance,   temporary  restraining  order  and/or  injunction.   The
         non-breaching  party's  right to such  equitable  remedies  shall be in
         addition to all other rights and remedies which the non-breaching party
         may  have  hereunder  or under  applicable  law,  including  a right to
         damages.

                  (e)  Unconditional  Obligation.  The  obligations set forth in
         this Section 5.4 to maintain the  confidentiality of and not wrongfully
         use the  Confidential  Information are  unconditional  and shall not be
         excused by any  conduct on the part of a party  except as  specifically
         set forth in Section 5.4(c).

         5.5 Offer of Employment.  During the period prior to the Closing, Buyer
may negotiate with and offer employment to current  employees of Seller.  In the
event that any current employee of Seller accepts employment with Buyer on terms
reasonably  satisfactory to Buyer,  then and in that event Seller will pay Buyer
at Closing  the amount of Seller  Assisted  Signing  Bonus  designated  for such
employee on Exhibit . In the event an employee who receives  payment of a Seller
Assisted Signing Bonus  terminates  employment with Buyer within four (4) months
after the Closing Date, Buyer will promptly  reimburse Seller a pro rata portion
of that employee's Seller Assisted Signing Bonus,  determined by multiplying the
amount thereof by a fraction,  the numerator of which is the number of whole and
partial  months  remaining to a date four (4) months after the Closing Date, and
the  denominator  of which is four (4).  Seller will terminate the employment of
any employee  hired by Buyer and the  employment of such employee by Buyer shall
be a new  employment  relationship.  Notwithstanding  the foregoing or any other
provision of this Agreement,  Seller  acknowledges  and agrees that Buyer has no
obligation  to employ any  current  employees  of Seller and that Seller will be
solely  responsible  for any  vacation  pay and any  other  obligations  to such
employees arising out of their employment with Seller.

         5.6 Cash  Payment.  Seller  will pay to  Buyer  at the  Closing  Twenty
Thousand  Dollars  ($20,000)  to assist the Buyer in effecting a transfer of the
FastCall Products from Seller to Buyer.


                                    ARTICLE 6

                CONDITIONS OF CLOSING; ABANDONMENT OF TRANSACTION

         6.1  Conditions to Obligations of Buyer to Proceed on the Closing Date.
The obligations of Buyer to proceed on the Closing Date shall be subject (at its
discretion)  to the  satisfaction,  on or  prior to the  Closing,  of all of the
following conditions:

                  (a) Truth of  Representations  and  Warranties  and Compliance
         with Obligations.  The  representations and warranties of Seller herein
         shall be true in all  material  respects on the  Closing  Date with the
         same effect as though made at such time.  Seller  shall have  performed
         all material  obligations and complied with all material  covenants and
         conditions prior to or as of the Closing Date.

                  (b)  Opinion of  Counsel.  Buyer  shall  have  received a duly
         executed  opinion  letter from  Seller's  legal counsel dated as of the
         Closing Date, in form and substance  reasonably  satisfactory  to Buyer
         and its counsel, to the effect that:

                           (i)  Seller  is  a  corporation  duly  organized  and
                  validly  existing  and  in  good  standing  in  the  State  of
                  Delaware;  has  all  necessary  corporate  power  to  own  its
                  properties and assets and to conduct its business as it is now
                  conducted;  and is  qualified  to do business in all states in
                  which  qualification  is  required  by the  nature  of the its
                  business  and where the  failure  to so  qualify  would have a
                  material adverse effect on the Purchased Assets;

                           (ii) This Agreement and all collateral documents have
                  been duly and validly  authorized,  executed and  delivered by
                  Seller, constitute the valid and binding obligations of Seller
                  and are enforceable in accordance with their terms,  except as
                  limited by bankruptcy  and  insolvency  laws and by other laws
                  affecting the rights of creditors generally;

                           (iii) To the best of such counsel's knowledge,  after
                  reasonable  inquiry,  no suit, action,  arbitration,  legal or
                  administrative  proceeding  is pending  against the  Purchased
                  Assets; and

                           (iv)  Neither  the  execution  nor  delivery  of this
                  Agreement,   nor   the   consummation   of  the   transactions
                  contemplated in this Agreement, will constitute a violation of
                  Seller's  Certificate of Incorporation  or Bylaws,  or, to the
                  best  of  such  counsel's  knowledge,   a  default  under,  or
                  violation  or breach of, any material  agreement  listed on an
                  Exhibit to this Agreement.

                  In giving such  opinion,  such counsel may rely, as to matters
         of fact, upon  certificates of officers of Seller or public  officials,
         and as to matters of law solely upon the laws of the State of Delaware.

                  (c) Required  Consents.  All required consents shall have been
         received  from  governmental  agencies  whose  approval  is required to
         consummate the transaction  contemplated herein and from each person or
         entity listed on Exhibit .

                  (d)  Delivery of  Documents.  Seller  shall have  executed and
         delivered  to Buyer  documents  assigning  all of its right,  title and
         interest  in  and  to the  Purchased  Assets;  and  Seller  shall  have
         delivered all documents required to be delivered at Closing pursuant to
         Section 7.2 hereof.

                  (e) Litigation  Affecting  Closing.  No suit,  action or other
         proceeding  shall be  pending or  threatened  by or before any court or
         governmental agency in which it is sought to restrain or prohibit or to
         obtain damages or other relief in connection with this Agreement or the
         consummation of the transaction  contemplated by this Agreement, and no
         investigation  that  may  result  in any  such  suit,  action  or other
         proceeding shall be pending or threatened.

                  (f) Legislation.  No statute,  rule, regulation or order shall
         have been  enacted,  entered or deemed  applicable  by any  domestic or
         foreign  government or governmental or  administrative  agency or court
         which would make the transaction contemplated by this Agreement illegal
         or otherwise  materially adversely affect the Purchased Assets or their
         use and operation in the hands of Buyer.

                  (g) Review of Records of the  Business.  Buyer  shall have had
         the  opportunity  prior to the  Closing  Date to  review  the  business
         records of the Seller relating to the Purchased Assets and to take such
         other  actions  as  specified  in  Section  5.1.  Buyer  shall not have
         discovered during such review any substantial  liabilities  relating to
         the Purchased  Assets which were not  previously  disclosed to Buyer in
         the this Agreement (including its Exhibits) or otherwise by Seller.

         6.2  Conditions to Obligation of Seller to Proceed on the Closing Date.
The obligation of Seller to proceed on the Closing Date shall be subject (at its
discretion)  to the  satisfaction,  on or before the Closing,  of the  following
conditions:

                  (a) Truth of  Representations  and  Warranties  and Compliance
         with Obligations.  The  representations  and warranties of Buyer herein
         contained  shall be true in all  material  respects on the Closing Date
         with the same  effect as though  made at such  time.  Buyer  shall have
         performed  all  material  obligations  and  complied  with all material
         covenants and conditions prior to or as of the Closing Date.

                  (b)  Opinion of  Counsel.  Seller  shall have  received a duly
         executed  opinion  letter from Buyer's  legal  counsel  dated as of the
         Closing Date, in form and substance  reasonably  satisfactory to Seller
         and its counsel, to the effect that:

                           (i) Buyer is a corporation duly organized and validly
                  existing and in good  standing in the State of  Minnesota  and
                  has all necessary  corporate  power to own its  properties and
                  assets and to conduct its business as it is now conducted;

                           (ii) This Agreement and all collateral documents have
                  been duly and validly  authorized,  executed and  delivered by
                  Buyer,  constitute the valid and binding obligations of Buyer,
                  and are enforceable in accordance with their terms,  except as
                  limited by bankruptcy  and  insolvency  laws and by other laws
                  affecting the rights of creditors generally;

                           (iii) To the best of such counsel's knowledge,  after
                  reasonable  inquiry,  no suit, action,  arbitration,  legal or
                  administrative proceeding, or any governmental  investigation,
                  is  pending  or  threatened  against  Buyer,  or any of  their
                  businesses or properties; and

                           (iv)  Neither  the  execution  nor  delivery  of this
                  Agreement,   nor   the   consummation   of  the   transactions
                  contemplated in this Agreement, will constitute a violation of
                  the Articles of  Incorporation  or Bylaws of Buyer, or, to the
                  best of such counsel's knowledge,  after reasonable inquiry, a
                  default  under,  or  violation  or breach of,  any  indenture,
                  license,  lease, mortgage,  instrument,  or other agreement to
                  which  Buyer is a party,  or by which  its  properties  may be
                  bound.

         In giving such  opinion,  such counsel may rely, as to matters of fact,
         upon certificates of officers of Buyer or public officials.

                  (c)  Delivery of  Documents.  Buyer shall have  delivered  all
         documents  required to be delivered at Closing  pursuant to Section 7.3
         hereof.

                  (d) Litigation  Affecting  Closing.  No suit,  action or other
         proceeding  shall be  pending or  threatened  by or before any court or
         governmental agency in which it is sought to restrain or prohibit or to
         obtain damages or other relief in connection with this Agreement or the
         consummation of the transaction  contemplated by this Agreement, and no
         investigation  that might  eventuate in any such suit,  action or other
         proceeding shall be pending or threatened.

                  (e) Legislation.  No statute,  rule, regulation or other shall
         have been  enacted,  entered or deemed  applicable  by any  domestic or
         foreign  government or governmental or  administrative  agency or court
         which  would  make  the  transaction  contemplated  by  this  Agreement
         illegal.

         6.3  Termination  of Agreement.  This  Agreement  and the  transactions
         contemplated  herein may be  terminated at or prior to the Closing Date
         as follows:

                  (a)      By mutual written consent of all parties.

                  (b) By Buyer pursuant to written notice  delivered at or prior
         to the Closing if Seller has failed in any material  respect to satisfy
         all of the conditions to Closing set forth in Section 6.1.

                  (c) By Seller pursuant to written notice delivered at or prior
         to the Closing if Buyer has failed in any  material  respect to satisfy
         the conditions set forth in Section 6.2.

         6.4  Consequences of  Termination.  In the event of termination of this
Agreement,  each  party will  return to the other all  documents  and  materials
obtained from the other in connection with the transaction  contemplated by this
Agreement  and  will  not  use  and  will  keep  confidential  all  Confidential
Information about the other party obtained  pursuant to this Agreement  pursuant
to the terms of Section 5.4 hereof.


                                   ARTICLE 7.

                                     CLOSING

         7.1  Closing.  The  closing  of the  transaction  contemplated  by this
Agreement  ("Closing")  shall be held at [the  offices of Buyer] on December 31,
1997,  at 1:00 p.m.,  or at such other date or time as the parties may  mutually
agree upon in writing. Such date of Closing is referred to herein as the Closing
Date.

         7.2  Documents to be Delivered by Seller.  Seller agrees to deliver the
following documents, duly executed as appropriate, to Buyer at the Closing:

                  (a)  Certified  copies  of  corporate  resolutions  of  Seller
         authorizing  it to enter  into this  Agreement  and to  consummate  the
         transactions contemplated herein.

                  (b) A Bill of Sale  for the  assignment  and  transfer  of the
         Purchased Assets.

                  (c) Appropriate  assignment documents assigning Seller's title
         and interest in and to the Purchased Assets.

                  (d) Opinion of  Seller's  Counsel as  required  under  Section
         6.1(b).

                  (e)  Documentation  of receipt of  consents  from all  persons
         listed on Exhibit , except as waived by Buyer.

                  (f)  Copies  in  hardcopy  and  machine  readable  code of all
         software comprising the FastCall Products, and the Computer Programs.

                  (g) Such other  documents as Buyer may reasonably  request for
         the  purpose  of  assigning,  transferring,  granting,  conveying,  and
         confirming to Buyer or reducing to its  possession all of the Purchased
         Assets.

         7.3 Documents Delivered by Buyer. Buyer agrees to deliver the following
documents, duly executed as appropriate, to Seller at the Closing:

                  (a)  Certified  copies  of  corporate   resolutions  of  Buyer
         authorizing  it to enter  into this  Agreement  and to  consummate  the
         transactions contemplated herein.

                  (b) Wire  transfer  of the net  amount of funds  described  in
         Section 2.2(a).

                  (c) Royalty-free  non-exclusive  License for Seller to use the
         Patents.

                  (d)  Opinion of  Buyer's  counsel as  required  under  Section
         6.2(b).

                  (e) An assumption of the obligations identified in Exhibit and
 .

                  (f) Such other  documents as Seller  reasonably may request to
         carry out the transactions contemplated under this Agreement.


                                   ARTICLE 8.

                            POST CLOSING OBLIGATIONS

         8.1 Covenant Not to Compete. Seller and Comdial Corporation ("Comdial")
covenant  and agree  (the  "Covenant  Not to  Compete")  that from and after the
Closing,  without the prior written consent of Buyer, neither Seller nor Comdial
(for  itself  and its  controlled  subsidiaries)  will  develop,  market or sell
desktop-based  screen pop products in competition with the Royalty Products sold
for use as  middleware  in  connection  with  telephone  systems  including  key
systems,  private  branch  exchanges  (PBX's) and  automatic  call  distribution
(ACD's)  ("Protected  Products") by the Buyer, in accordance with and subject to
the following provisions:

                  (a) The term "Protected  Products" shall not include  products
         used in connection with telephone systems including key systems,  PBX's
         and ACD's sold by Comdial or its  subsidiaries,  or marketed  under the
         Comdial(R) name.

                  (b) The term  "Protected  Products"  shall not include  visual
         call products  developed,  marketed or sold by Key Voice  Technologies,
         Inc., a subsidiary of Comdial,  or by any other  subsidiary of Comdial,
         such as the  Key  Voice  Visual  Call  management  products  and  their
         derivatives or replacements.

                  (c) The  Covenant  Not to Compete  shall expire five (5) years
         after the Closing Date.

         8.2 Further Documents and Assurances. At any time and from time to time
after the  Closing  Date,  each party  shall,  upon  request  of another  party,
execute,  acknowledge  and deliver all such  further  and other  assurances  and
documents,  and  will  take  such  action  consistent  with  the  terms  of this
Agreement,  as may  be  reasonably  requested  to  carry  out  the  transactions
contemplated  herein and to permit  each party to enjoy its rights and  benefits
hereunder.  If requested by Buyer,  each of Seller and Comdial  further agree to
prosecute  or  otherwise  enforce  in its own name for the  benefit of Buyer any
claim,  right  or  benefit  transferred  by  this  Agreement  that  may  require
prosecution  or enforcement  in Seller's or Comdial's  name. Any  prosecution or
enforcement of claims,  rights, or benefits under this provision shall be solely
at Buyer's expense, unless the prosecution or enforcement is made necessary by a
breach of this Agreement on the part of Seller or Comdial.

         8.3 Consulting. For a period of ninety (90) days after the Closing Date
Seller  or  Comdial  will  make  available  to Buyer up to fifty  (50)  hours of
consulting  services  each from Paul M. Gasparro and, to the extent she does not
become an employee of Buyer, Sandra Scheer. Such consulting services shall be at
no cost to Buyer, except that Buyer will be responsible for any necessary travel
expenses  incurred  at  Buyer's  request.  Notwithstanding  the  foregoing,  the
obligation  of Seller and Comdial to provide  consulting  services  from Paul M.
Gasparro and Sandra Scheer shall be contingent upon their continued  employment,
respectively, with Seller or Comdial.

         8.4 Accounts  Receivable.  Seller shall use its normal business efforts
to collect the Excess Accounts Receivable for the benefit of Buyer, and remit to
Buyer all payments received thereon as and when collected.  The Seller shall not
be obligated  to  institute  legal  proceedings  to collect the Excess  Accounts
Receivable.  At any time at the written request of Buyer,  and on March 31, 1998
in any event,  Seller will assign the uncollected Excess Accounts  Receivable to
Buyer and Seller shall have no further obligation to Buyer with respect thereto.

         8.5 Un-Invoiced Sales. Buyer may invoice customers for amounts owing to
Seller on account of the  Un-Invoiced  Sales and may  collect  the same.  Seller
shall have no obligation to Buyer with respect thereto.

         8.6.  Fleet  Capital  Corporation  Releases.  Within 20 days  after the
Closing  Date,  Seller and its parent  company,  Comdial  Corporation,  agree to
obtain releases of the Fleet Liens against the Purchased  Assets as set forth on
Exhibit 3.5 hereto,  including,  but not limited to,  partial  releases  for the
original financing  statements filed by Fleet Capital Corporation against Seller
in  Massachusetts  and  Virginia  as well as a partial  release of the  Security
Agreement-Intellectual   Property  to  release  the  patents,   trademarks   and
copyrights  identified  on Exhibits  1.1(a) and 1.1(b) of this  Agreement.  Such
releases  shall be in  recordable  form and otherwise  reasonably  acceptable to
Purchaser.


                                   ARTICLE 9.

                                 INDEMNIFICATION

         9.1 Indemnification by Seller.  Subject to the limitations set forth in
Section 9.2,  Seller and Comdial shall  indemnify and hold Buyer harmless at all
times from and after the date of this  Agreement  against  and in respect of all
damages, losses, costs and expenses (including reasonable attorneys' fees) which
Buyer may suffer or incur in connection with any of the following matters:

                  (a) Any claim,  demand,  action or  proceeding  asserted  by a
         creditor of Seller under the provisions of any applicable Bulk Transfer
         Act or asserted  by any other  person  respecting  any  liabilities  of
         Seller which are not expressly assumed by Buyer under this Agreement.

                  (b) A material breach by Seller of any of its representations,
         warranties or covenants in this Agreement.

         9.2      Seller's Limitation of Liability.

                  (a) Buyer shall assert any claim under  Section  9.1(b) within
         twelve  (12) months  from the  Closing  Date or be forever  barred from
         asserting such claim.

                  (b) The  rights of Buyer with  respect  to any claims  arising
         under Section 9.1 shall be limited to recovery of actual losses,  costs
         and  expenses  (including  reasonable  attorneys'  fees).  Buyer hereby
         waives any remedy or right of  rescission  arising on the basis of such
         claims.

         9.3 Indemnification by Buyer. Buyer shall indemnify and hold Seller and
Comdial harmless at all times from and after the date of this Agreement, against
and in respect of all losses,  damages, costs and expenses (including reasonable
attorneys'  fees) which Seller or Comdial may suffer or incur in connection with
any of the following matters:

                  (a)  A  material  breach  by  Buyer  of  any  representations,
         warranties or covenants in this Agreement.

                  (b) Any claim,  demand,  action or proceeding  asserted by any
         person against Seller or Comdial or any of its subsidiaries relating to
         any obligation or liability imposed on or assumed by Buyer hereunder or
         to  any  obligation  or  liability  relating  to the  Royalty  Products
         incurred after the Closing.

         9.4      Buyer's Limitation of Liability.

                  (a)  Seller or  Comdial  shall  assert  any such  claim  under
         Section  9.2(a)  within  twelve (12)  months of the Closing  Date or be
         forever barred from asserting such claim.

                  (b) The rights of Seller or Comdial with respect to any claims
         arising  under  Section  9.3 shall be  limited  to  recovery  of actual
         losses,  costs and expenses  (including  reasonable  attorney's  fees).
         Seller and Comdial hereby waive any remedy or right of recision arising
         on the basis of such claims.

         9.5  Limitations  on  Indemnification.  Notwithstanding  the  foregoing
provisions of this Article,  neither Seller nor Comdial shall be liable to Buyer
under Section 9.1 unless and until the aggregate  amount of liability under such
Section  exceeds   [$17,500],   and  thereafter   Buyer  shall  be  entitled  to
indemnification  thereunder  only for the aggregate  amount of such liability in
excess of  [$17,500].  Buyer  shall not be  liable  to Seller or  Comdial  under
Section  9.3  unless  and until the  aggregate  amount of  liability  under such
Section exceeds  [$17,500],  and thereafter Seller and Comdial shall be entitled
to indemnification thereunder only for the aggregate amount of such liability in
excess of [$17,500].  In no event shall either Buyer's  liability or Seller's or
Comdial's liability under Sections 9.1 and 9.3 exceed the Purchase Price.

         9.6 Third Party Claims. If a claim by a third party is made against any
of the indemnified  parties,  and if any of the  indemnified  parties intends to
seek indemnity with respect to such claim under this Article,  such  indemnified
party  shall  promptly  notify  the  indemnifying   party  of  such  claim.  The
indemnifying   party  shall  have   thirty  (30)  days  after   receipt  of  the
above-mentioned  notice to undertake,  conduct and control,  through  counsel of
such party's own choosing (subject to the consent of the indemnified party, such
consent  not to be  unreasonably  withheld)  and at such  party's  expense,  the
settlement or defense of it, and the indemnified  party shall cooperate with the
indemnifying  party in connection  with such  efforts;  provided  that:  (i) the
indemnifying  party  shall  not by this  Agreement  permit  to exist  any  lien,
encumbrance  or other adverse  charge upon any asset of any  indemnified  party,
(ii) the indemnifying party shall permit the indemnified party to participate in
such  settlement or defense  through  counsel chosen by the  indemnified  party,
provided  that the  fees  and  expenses  of such  counsel  shall be borne by the
indemnified  party,  and (iii) the  indemnifying  party shall agree  promptly to
reimburse the  indemnified  party for the full amount of any loss resulting from
such claim and all related expense incurred by the indemnified party pursuant to
this Article.  So long as the  indemnifying  party is reasonably  contesting any
such claim in good faith, the indemnified party shall not pay or settle any such
claim. If the  indemnifying  party does not notify the indemnified  party within
thirty (30) days after receipt of the  indemnified  party's notice of a claim of
indemnity  under this Article that such party elects to undertake the defense of
such claim,  the  indemnified  party shall have the right to contest,  settle or
compromise  the  claim in the  exercise  of the  indemnified  party's  exclusive
discretion at the expense of the indemnifying party.


                                   ARTICLE 10.

                                     GENERAL

         10.1  Assignment.  This Agreement may be assigned by the Buyer, and the
Royalty  Products sold or  transferred  by the Buyer,  without the prior written
consent of Seller only on the following terms:

                  (a) The Buyer shall pay to Seller the amount, if any, by which
         the Minimum  Purchase  Price exceeds the Total Payment Amount as of the
         date of such assignment, sale or transfer; and

                  (b) The  assignee  of or  purchaser  from the Buyer  agrees in
         writing  and for the benefit of Seller to be bound by the terms of this
         Agreement to the same extent as the Buyer,  and Buyer furnishes  Seller
         with an  appropriate  written  agreement to this effect duly signed and
         delivered by such assignee or purchaser.

         10.2  Counterparts.  This Agreement may be executed in counterparts and
by different  parties on different  counterparts  with the same effect as if the
signatures  thereto  were  on the  same  instrument.  This  Agreement  shall  be
effective  and  binding  upon all  parties  hereto as of when all  parties  have
executed a counterpart of this Agreement.

         10.3  Exhibits.  Each Exhibit  delivered  pursuant to the terms of this
Agreement shall be in writing and shall constitute a part of this Agreement.

         10.4 Notices.  Any notice or other communication  required or permitted
hereunder  shall be in  writing  and shall be deemed  to have been  given,  when
received,  if  delivered  by  hand,  telegram,  telex  or  telecopy,  and,  when
deposited,  if placed in the mails for  delivery by air mail,  postage  prepaid,
addressed  to the  appropriate  party as  specified  on the  first  page of this
Agreement.  Addresses  may be changed by written  notice given  pursuant to this
section,  provided that any such notice shall not be effective, if mailed, until
three (3) working days after depositing in the mails or when actually  received,
whichever occurs first.

         10.5  Successors and Assigns.  Neither Seller nor Buyer shall assign or
transfer any of its rights or  obligations  hereunder  without the prior written
consent of the other party which consent shall not be unreasonably withheld.

         10.6 Expenses.  Except as otherwise provided herein,  each party hereto
shall  bear and pay for its own  costs  and  expenses  incurred  by it or on its
behalf in  connection  with the  transactions  contemplated  hereby,  including,
without  limitation,  all fees and  disbursements of attorneys,  accountants and
financial consultants incurred through the Closing Date.

         10.7 Entire Agreement.  This Agreement,  together with the Exhibits and
the related written agreements  specifically referred to herein,  represents the
only  agreement  among the  parties  concerning  the subject  matter  hereof and
supersedes all prior agreements whether written or oral, relating thereto.

         10.8 Modification and Waiver. No purported  amendment,  modification or
waiver of any  provision  hereof shall be binding  unless set forth in a written
document signed by all parties (in the case of amendments or  modifications)  or
by the party to be charged thereby (in the case of waivers). Any waiver shall be
limited to the  circumstance  or event  specifically  referenced  in the written
waiver  document and shall not be deemed a waiver of any other term hereof or of
the same circumstance or event upon any recurrence thereof.

         10.9  Publicity.  Seller and Buyer each  represent  and warrant that it
will make no announcement  to public  officials or the press in any way relating
to the  transaction  described  herein without the prior written  consent of all
parties.

         10.10 Governing Law. This Agreement and the legal relations between the
parties shall be governed by and  construed in  accordance  with the laws of the
State of Minnesota.

         10.11  Knowledge.   Knowledge,   as  used  in  this  Agreement  or  the
instruments,  certificates  or other  documents  required under this  Agreement,
means  actual  knowledge  of a fact or  constructive  knowledge  if a reasonably
prudent  person in a like position would have known,  or should have known,  the
fact.

         10.12  Benefit.  Nothing in this  Agreement,  expressed or implied,  is
intended  to confer on any person  other than the parties to this  Agreement  or
their  permitted  successors or assigns,  any rights,  remedies,  obligations or
liabilities under or by reason of this Agreement.

         10.13 Comdial Corporation. Comdial executes this Agreement for the sole
purposes of (a) evidencing its  obligations  expressly set forth in Articles and
hereof, (b) confirming that the financial information attached hereto as Exhibit
is true and correct,  and (c)  confirming  that it has  accurately  prepared and
timely  filed the tax returns  described in Section , and has paid the taxes due
thereon except as disclosed in Exhibit .


         IN WITNESS WHEREOF, each of the parties hereto has caused this FastCall
Purchase  Agreement  to be executed  in the manner  appropriate  to each,  to be
effective as of the day and year first above written.

                               SPANLINK COMMUNICATIONS, INC. ("Buyer")

                               By     \s\ T. E. Briggs
                                  Its    Chief Financial Officer


                               AURORA SYSTEMS, INC. ("Seller")

                               By     \s\ Linda P. Falconer
                                  Its    Assistant Secretary


                               COMDIAL CORPORATION

                               By      \s\ Linda P. Falconer
                                  Its    Assistant Secretary