EXHIBIT 10.27

   Confidential  Materials  omitted  and   filed  separately  with   the
   Securities and Exchange Commission.  Asterisks denote omissions.

   OPERATING AGREEMENT

        This Agreement  is  entered into  as  of October 19,  1998  (the
   "Effective Date") among Spyglass, Inc., a Delaware corporation having
   a principal  place of  business at  1240 E.  Diehl Road,  4th  Floor,
   Naperville, IL 60563  ("Spyglass"), Spyglass DSIC,  Inc., a  Delaware
   corporation having a  principal place of  business at  1240 E.  Diehl
   Road, 4th Floor, Naperville, IL 60563 (the "Subsidiary"), and General
   Instrument Corporation,  a Delaware  corporation  having a  place  of
   business at 101 Tournament Drive, Horsham, Pennsylvania 19044 ("GI").
    Spyglass, the Subsidiary and  GI are hereinafter sometimes  referred
   to individually as a "Party" and collectively as the "Parties."

        WHEREAS, contemporaneously with the execution of this Agreement,
   the Company and the  Purchaser are entering  into a Digital  Software
   Integration Center Sourcing Agreement (the "Sourcing Agreement");

        WHEREAS, contemporaneously with the execution of this Agreement,
   the Company has organized the Subsidiary for the purpose of operating
   and managing a Digital Software Integration Center in accordance with
   the terms of the Sourcing Agreement:

        WHEREAS, Spyglass, the  Subsidiary and GI  desire to enter  into
   this Agreement for  the purpose  of establishing  certain rights  and
   obligations with respect to the Subsidiary;

        NOW, THEREFORE,  in consideration  of  the mutual  promises  and
   covenants contained in this Agreement and for other good and valuable
   consideration, the  receipt  and  sufficiency  of  which  are  hereby
   acknowledged, Spyglass, the Subsidiary and  GI, each intending to  be
   legally bound, hereby agree as follows:

        1.   Organization of Subsidiary.

             1.1  Spyglass  organized  the  Subsidiary  as  a   Delaware
   corporation on October 14, 1998.   The Subsidiary  has engaged in  no
   activities to  date  other  than  routine  matters  incident  to  its
   organization.

             1.2  The Certificate of  Incorporation and  By-laws of  the
   Subsidiary  are  attached  hereto  as   Exhibit  A  and  Exhibit   B,
   respectively.  The Board of Directors  of the Subsidiary consists  of
   Douglas P. Colbeth and Gary Vilchick.

             1.3  Promptly following  the execution  of this  Agreement,
   (a) the Subsidiary shall issue and sell, and Spyglass shall purchase,
   900 shares of the common stock, $.01 par value per share (the "Common
   Stock"), of the Subsidiary for a purchase price of *** per share, and

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             Confidential Materials  omitted and  filed separately  with
   the Securities and Exchange Commission.  Asterisks denote omissions.

             (b) the Subsidiary  shall  issue  and sell,  and  GI  shall
   purchase, 100 shares of Common Stock of the Subsidiary for a purchase
   price of *** per share.

             1.4  Each of  Spyglass and  GI represents  as follows  with
   respect to its purchase of Common Stock of the Subsidiary:

                  (a)  It is purchasing such shares for its own  account
   for investment  only,  and  not  with  a view  to,  or  for  sale  in
   connection with, any distribution of such shares in violation of  the
   Securities Act  of  1933  (the "Securities  Act"),  or  any  rule  or
   regulation under the Securities Act. 

                  (b)  It understands that (i) such shares have not been
   registered under the Securities  Act and are "restricted  securities"
   within the meaning of Rule 144 under the Securities Act and (ii) such
   shares cannot be  sold, transferred or  otherwise disposed of  unless
   they are  subsequently  registered under  the  Securities Act  or  an
   exemption from registration is then available. 

                  (c)  Legends substantially in the following form  will
   be placed on the certificate representing such shares: 

             "The shares represented by this certificate  have
             not been registered under  the Securities Act  of
             1933,  as   amended,  and   may  not   be   sold,
             transferred  or  otherwise  disposed  of  in  the
             absence of  an effective  registration  statement
             under  such  Act   or  an   opinion  of   counsel
             satisfactory to  the  corporation to  the  effect
             that such registration is not required."  

             "The shares represented  by this certificate  are
             subject  to  restrictions   on  transfer  and   a
             purchase option set forth in an agreement between
             Spyglass, Inc.  and certain  other parties  dated
             October 19, 1998, a  copy of  which is  available
             upon request to the Secretary of Spyglass, Inc."

        2.   Operation of Subsidiary.

             2.1  The Subsidiary  shall not  engage in  any  activities,
   shall not acquire  any assets, shall  not incur  any liabilities  and
   shall not  hire any  personnel except  for  the specific  purpose  of
   performing services for GI under the Sourcing Agreement and otherwise
   in accordance with the terms of the Sourcing Agreement.
   Confidential  Materials  omitted  and   filed  separately  with   the
   Securities and Exchange Commission.  Asterisks denote omissions.

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             2.2  Without  limiting  the   restrictions  set  forth   in
   Section 2.1, the  Subsidiary shall  not,  without the  prior  written
   consent of both Spyglass and GI, take any of the following actions:
                  (a)  amend its  Certificate  of Incorporation  or  By-
                       laws;

                  (b)  issue any shares of  capital stock, or any  other
   securities exercisable for, convertible into or exchangeable for  any
   shares of capital stock of the Subsidiary;

                  (c)  declare or pay any dividends or distributions  on
   its  outstanding  Common  Stock   or  repurchase  or  reacquire   any
   outstanding shares of its Common Stock;

                  (d)  merge with or into or consolidate with any  other
   entity, or sell or otherwise dispose  of all or substantially all  of
   its properties or assets to any other entity; or

                  (e)  voluntarily liquidate or dissolve.

             2.3  The Subsidiary will operate its business in compliance
   with all laws, rules and regulations applicable to the Subsidiary and
   its business.

        3.   Purchase Option.   GI shall have  an option (the  "Purchase
   Option") to purchase, for  cash, all (but not  less than all) of  the
   shares of Common Stock of the Subsidiary owned by Spyglass, upon  the
   terms and conditions set forth in this Section 3.

             3.1  Term of the Purchase Option.

                  (a)  The Purchase Option shall become exercisable upon
   the earliest to occur of the following dates:  (i) ***, provided that
   if GI  elects  to extend,  pursuant  to  the terms  of  the  Sourcing
   Agreement, the expiration of the Sourcing Agreement from  October 31,
   2001 to October 31,  2002, the Purchase  Option shall instead  become
   exercisable on ***; (ii) the date on which the Sourcing Agreement  is
   terminated by GI pursuant to Section 11.3 of the Sourcing  Agreement;
   and (iii) the date on which a Spyglass Change in Control (as  defined
   below) occurs.  If the  Purchase Option becomes exercisable  pursuant
   to clause  (i) of  this Section  3.1(a),  the Purchase  Option  shall
   continue in effect until April 30, 2001  or (if GI elects to  extend,
   pursuant to the terms  of the Sourcing  Agreement, the expiration  of
   the Sourcing  Agreement from  October 31, 2001  to October 31,  2002)
   April 30, 2002.  If the Purchase Option becomes exercisable  pursuant
   to clauses (ii) or (iii) of this Section 3.1(a), the Purchase  Option
   shall continue in effect through and  including the date that is  six
   months  after  the   date  on  which   the  Purchase  Option   became
   exercisable.    The  period  during  which  the  Purchase  Option  is
   exercisable shall be  referred to in  this Agreement  as the  "Option
   Term."

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        Confidential Materials  omitted and  filed  separately
   with the  Securities  and  Exchange  Commission.    Asterisks  denote
   omissions.

                  (b)  For  purposes  of  this  Agreement,  a  "Spyglass
   Change in  Control"  shall mean  the  consummation of  (i) a  merger,
   consolidation,  reorganization,  recapitalization  or  tender   offer
   involving Spyglass, immediately following  which the individuals  and
   entities who  were  the beneficial  owners  of the  Common  Stock  of
   Spyglass immediately  prior  to such  transaction  beneficially  own,
   directly or indirectly, less than 60% of the combined voting power of
   the then-outstanding  securities entitled  to vote  generally in  the
   election of  directors  of Spyglass  or  the resulting  or  acquiring
   corporation  in   such  transaction,   (ii) the   sale  of   all   or
   substantially all of the assets of Spyglass, or (iii) the acquisition
   by any  of  the companies  listed  on Exhibit C  attached  hereto  of
   beneficial ownership  (within the  meaning  of Section 13(d)  of  the
   Securities Exchange  Act  of  1934) of  shares  of  common  stock  of
   Spyglass representing 20% or more of the outstanding common stock  of
   Spyglass.

             3.2  Purchase Price.  The purchase price  to be paid by  GI
   to Spyglass for the shares of Common Stock of the Subsidiary owned by
   Spyglass (the "Purchase Price") shall be *** of the fair market value
   of the Subsidiary as  of the date on  which GI delivers the  Exercise
   Notice (as defined  in Section 3.3(a) below)  to Spyglass (the  "Fair
   Market Value"), to be determined as follows:

                  (a)  Upon the delivery by GI of an Exercise Notice  to
   Spyglass, GI and Spyglass  shall commence discussions regarding,  and
   shall use good faith efforts to  agree upon, the Fair Market Value.  
   If GI and  Spyglass reach  such an  agreement, they  shall execute  a
   written instrument setting forth the agreed-upon Fair Market Value.

                  (b)  If GI and  Spyglass do  not agree  upon the  Fair
   Market Value within 30 days after  the date (the "Exercise Date")  on
   which GI delivers the Exercise Notice to Spyglass, then:

                       (i)  The Fair Market Value  shall be the  average
   of the estimates, by each of three investment banking firms  selected
   in accordance with this Section  3.2(b) (the "Investment Banks"),  of
   the Fair Market Value.

                       (ii) GI and Spyglass shall each select, within 45
   days of the  Exercise Date, one  Investment Bank,  and shall  deliver
   notice to each other of the Investment Bank so selected.  Neither  GI
   nor Spyglass  may select  an Investment  Bank  after such  Party  has
   received notice that such  Investment Bank has  been selected by  the
   other Party.    Spyglass and  GI  shall cause  the  Investment  Banks

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   selected by them to together select a third Investment Bank no  later
   than 30 days following the Exercise Date. 

                       (iii)     Promptly following the selection of the
   third Investment Bank, GI and Spyglass shall jointly engage the three
   Investment Banks to make a written estimate of the fair market  value
   of the  Subsidiary as  of the  Exercise  Date (without  applying  any
   discount due to  a lack  of a public  trading market  for the  Common
   Stock of the Subsidiary), and to deliver to each of GI and  Spyglass,
   as soon  as practicable,  but in  any  event no  later than  75  days
   following the Exercise Date, a  written valuation report stating  the
   estimated fair market value  of the Subsidiary  and setting forth  in
   reasonable  detail  the  methodology  by  which  such  estimate   was
   determined.  The  valuation estimates by  each Investment Bank  shall
   take into  account  such factors  as  such Investment  Bank,  in  its
   reasonable discretion, deems relevant, which factors may include  the
   valuations of comparable privately or publicly held companies and the
   estimated value of the equity of  the Subsidiary in a private  equity
   financing, an initial public offering,  and/or an acquisition of  the
   entire company.  The valuation  estimates prepared by the  Investment
   Banks shall be binding upon both  GI and Spyglass and neither GI  nor
   Spyglass  may  dispute  the  fair  market  value  estimates  or   the
   methodologies used in arriving at such estimates.

                       (iv) GI shall pay  the fees and  expenses of  the
   Investment Bank  selected by  it; Spyglass  shall  pay the  fees  and
   expenses of the Investment Bank selected  by it; and GI and  Spyglass
   shall each  pay  one-half of  the  fees  and expenses  of  the  third
   Investment Bank.

             3.3  Exercise Procedure.

                  (a)  To exercise the Purchase Option, GI must  deliver
   a written notice  to Spyglass  (the "Exercise  Notice") which  states
   GI's election to exercise the Purchase Option and specifies a closing
   date for the exercise  of the Purchase  Option (the "Closing  Date"),
   which date shall be no earlier than 60 days and no later than 90 days
   after the Exercise Date; provided that if the Purchase Option becomes
   exercisable pursuant  to  clause (i) of Section 3.1(a),  the  Closing
   Date  specified  shall  be  the  expiration  date  of  the   Sourcing
   Agreement.  The Exercise Notice must  be delivered by GI to  Spyglass
   during the Option Term (although the Closing Date may occur after the
   expiration of the  Option Term,  subject to  the time  limits in  the
   preceding sentence).  If  GI does not deliver  an Exercise Notice  to
   Spyglass prior to  the expiration of  the Option  Term, the  Purchase
   Option shall expire.  GI shall be under no obligation to exercise the
   Purchase Option.  GI's delivery of an Exercise Notice shall be deemed
   an irrevocable commitment to purchase the  shares of Common Stock  of
   the Subsidiary owned by Spyglass, subject to the terms and conditions
   set forth in this Section 3.


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                  (b)  On the Closing Date,  subject to compliance  with
   all applicable laws and regulations (including without limitation the
   Hart-Scott-Rodino Antitrust Improvements Act of 1976):

                       (i)  Spyglass shall  deliver to  GI: (A)  one  or
   more stock certificates  representing the shares  of Common Stock  of
   the  Subsidiary  owned  by  Spyglass,  duly  endorsed  in  blank   or
   accompanied by duly executed stock  powers; (B) a certificate of  the
   Secretary of  Spyglass certifying  that Spyglass  is the  record  and
   beneficial owner of such shares of Common Stock, and that such shares
   are not  subject to  any lien,  pledge,  security interest  or  other
   encumbrance; and (C) a certificate of the  Secretary of State of  the
   State of  Delaware certifying  as to  the  legal existence  and  good
   standing of both the Subsidiary and Spyglass; and

                       (ii)      GI  shall:  (A)  pay  to  Spyglass  the
   amount of  the Purchase  Price, by  a  wire transfer  of  immediately
   available funds to an account designated by Spyglass; and (B) deliver
   to Spyglass a certificate of the  Secretary of State of the State  of
   Delaware certifying as to  the legal existence  and good standing  of
   GI.

                  (c)  If on the scheduled Closing Date the consummation
   of the  purchase  and sale  of  the shares  of  Common Stock  of  the
   Subsidiary owned by Spyglass cannot  take place because the  Purchase
   Price has not yet been determined or because a legal requirement  for
   the  consummation  of  such  purchase  and  sale  has  not  yet  been
   satisfied, the  scheduled  Closing Date  shall  be deferred  until  a
   mutually agreeable later  date.  If  such purchase and  sale has  not
   been consummated by  the date 120  days following  the Exercise  Date
   (or,  if  the   Purchase  Option  became   exercisable  pursuant   to
   clause (i) of Section 3.1(a),  by  the  date 30  days  following  the
   scheduled Closing Date), then  either GI or  Spyglass shall have  the
   right to cancel such pending purchase and sale; provided that neither
   GI nor Spyglass  may cancel  such pending  purchase and  sale if  the
   failure to consummate such purchase and sale results primarily from a
   breach by such Party of any provision contained in this Agreement  or
   a failure  by such  Party to  use good  faith efforts  to effect  the
   consummation of such purchase and sale.

             3.4  Restrictions on Transfer. 

                  (a)  Until  such  time  as  the  Purchase  Option  has
   expired unexercised, Spyglass shall  not sell, transfer or  otherwise
   dispose of, and shall  not pledge or otherwise  encumber, any of  the
   shares of Common Stock  of the Subsidiary owned  by Spyglass, and  no
   such pledge  or encumbrance  currently exists.   Notwithstanding  the
   foregoing sentence, Spyglass may transfer its shares of Common  Stock
   of the Subsidiary to a wholly-owned subsidiary of Spyglass,  provided
   such subsidiary delivers a written notice to GI agreeing to be  bound

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<PAGE>
   Confidential Materials omitted and filed separately with the 
   Securities and Exchange Commission.  Asterisks denote omissions.
                                     
   by the terms and  conditions of this Agreement  with respect to  such
   shares of the Subsidiary.

                  (b)  Until  such  time  as  the  Purchase  Option  has
   expired unexercised, GI shall not sell, transfer or otherwise dispose
   of, and shall not pledge or otherwise encumber, any of the shares  of
   Common Stock of  the Subsidiary owned  by GI, and  no such pledge  or
   encumbrance  currently   exists.     Notwithstanding  the   foregoing
   sentence,  GI  may  transfer  its  shares  of  Common  Stock  of  the
   Subsidiary  to  a  wholly-owned  subsidiary  of  GI,  provided   such
   subsidiary delivers a written notice to Spyglass agreeing to be bound
   by the terms and  conditions of this Agreement  with respect to  such
   shares of the Subsidiary.
 
             3.5  Restrictions Regarding Employees.  From and after  the
   Exercise  Date,  Spyglass  shall  not  hire  any  employees  of   the
   Subsidiary, reassign their employment responsibilities such that they
   are performing services for Spyglass (rather than the Subsidiary)  or
   terminate their employment except for valid reasons.

        4.   Management Services.

             4.1  Spyglass shall  provide to  the Subsidiary,  upon  the
   request of the Subsidiary,  the following administrative and  support
   services:  accounting  (including processing  of accounts  receivable
   and  accounts   payable),  payroll   processing,  employee   benefits
   administration, and such other administrative and support services as
   Spyglass  and  the  Subsidiaries  shall  mutually  agree  upon.    In
   addition, Spyglass shall  provide executive  management services  and
   advice to the Subsidiary to assist  it in performing its  obligations
   under the Sourcing Agreement.

             4.2  As consideration  for  the provision  of  services  by
   Spyglass to the  Subsidiary under Section  4.1, the Subsidiary  shall
   pay ***, of  the Subsidiary for  each fiscal year  of the  Subsidiary
   (beginning with  the  fiscal  year ending  September  30,  1999),  as
   determined  in   accordance   with  generally   accepted   accounting
   principles and  Spyglass'  accounting  principles  and  practices  as
   reflected  in  its  audited  financial  statements  filed  with   the
   Securities and Exchange Commission.   Such fees  shall be payable  by
   the Subsidiary to Spyglass on a  quarterly basis (with any  necessary
   adjustments made based upon actual  financial results for the  fiscal
   year), or in  accordance with such  other schedule as  may be  agreed
   upon by Spyglass and  the Subsidiary.  Spyglass  shall be liable  for
   and shall pay all federal, state, local and foreign taxes incurred by
   the Subsidiary as a result of its existence and operations.

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             4.3  Spyglass shall  use good  faith efforts  in  providing
   services to the Subsidiary  under this Section 4,  and shall use  the
   same degree of  care in  providing such  services as  it utilizes  in
   providing such services for  its own operations.   In no event  shall
   Spyglass be  liable  for any  error  or omission  in  providing  such
   services, or defect in the services  provided, except for any  error,
   omission, or defect  attributable to the  gross negligence or  wilful
   misconduct  of  Spyglass.     Spyglass   makes  no   representations,
   warranties or  guaranties,  express  or  implied  (including  without
   limitation  any  warranty  of   merchantability  or  fitness  for   a
   particular purpose)  with respect  to the  services provided  to  the
   Subsidiary under this Section 4, and shall not be liable for any lost
   profits or special, incidental or consequential damages caused by any
   delay in providing or any failure to provide such services.

             4.4  The provisions of Sections 4.1 and 4.2 shall terminate
   upon the expiration or termination of the Sourcing Agreement.

        5.   Representations of  Spyglass.   Spyglass hereby  represents
   and warrants to GI as follows:

             5.1  Organization and Standing.  Spyglass is a  corporation
   duly organized, validly existing and in good standing under the  laws
   of the State of Delaware.

             5.2  Authorization  of  Transaction.    Spyglass  has   all
   requisite power and authority to  execute and deliver this  Agreement
   and to perform its obligations hereunder.  The execution and delivery
   of  this  Agreement   by  Spyglass  and   the  consummation  of   the
   transactions contemplated  hereby  by  Spyglass have  been  duly  and
   validly authorized by all necessary corporate  action on the part  of
   Spyglass.   This Agreement  has been  duly and  validly executed  and
   delivered by Spyglass and constitutes a valid and binding  obligation
   of Spyglass, enforceable against it in accordance with its terms.

             5.3  Noncontravention.  Neither the execution and  delivery
   of this Agreement by  Spyglass, nor the  consummation by Spyglass  of
   the transactions contemplated hereby, (a) conflicts with or  violates
   any provision  of  the Certificate  of  Incorporation or  By-laws  of
   Spyglass, (b) requires on  the part of Spyglass  any filing with,  or
   permit, authorization,  consent  or  approval  of,  any  governmental
   entity, (c) conflicts  with,  results  in breach  of,  constitutes  a
   default under, or requires any notice,  consent or waiver under,  any
   contract, agreement or other instrument to which Spyglass is a  party
   or by which it is bound (other  than any consent or waiver which  has
   already been obtained), or (d) violates any order, writ,  injunction,
   decree, statute, rule or regulation applicable to Spyglass.

        6.   Representations of the Subsidiary.   The Subsidiary  hereby
   represents and warrants to GI as follows:


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             6.1  Organization  and  Standing.    The  Subsidiary  is  a
   corporation duly  organized, validly  existing and  in good  standing
   under the laws of the State of Delaware.

             6.2  Capitalization.  The authorized  capital stock of  the
   Subsidiary consists of 1,000 shares of  Common Stock, $.01 par  value
   per share,  none of  which are  issued or  outstanding.   All of  the
   shares of Common Stock  of the Subsidiary to  be  issued pursuant  to
   this Agreement will be, when so  issued, duly authorized and  validly
   issued and fully paid and nonassessable.

             6.3  Authorization of Transaction.  The Subsidiary has  all
   requisite power and authority to  execute and deliver this  Agreement
   and to perform its obligations hereunder.  The execution and delivery
   of this  Agreement by  the Subsidiary  and  the consummation  of  the
   transactions contemplated hereby by the Subsidiary have been duly and
   validly authorized by all necessary corporate  action on the part  of
   the Subsidiary.  This  Agreement has been  duly and validly  executed
   and delivered by the Subsidiary and  constitutes a valid and  binding
   obligation of the  Subsidiary, enforceable against  it in  accordance
   with its terms.

             6.4  Noncontravention.  Neither the execution and  delivery
   of this  Agreement by  the Subsidiary,  nor the  consummation by  the
   Subsidiary of  the transactions  contemplated hereby,  (a)  conflicts
   with or violates any provision of the Certificate of Incorporation or
   By-laws of the Subsidiary, (b) requires on the part of the Subsidiary
   any filing with,  or permit, authorization,  consent or approval  of,
   any governmental entity,  (c) conflicts with, results  in breach  of,
   constitutes a  default  under, or  requires  any notice,  consent  or
   waiver under, any  contract, agreement or  other instrument to  which
   the Subsidiary is a  party or by  which it is  bound (other than  any
   consent or waiver which has already  been obtained), or (d)  violates
   any order,  writ, injunction,  decree,  statute, rule  or  regulation
   applicable to the Subsidiary.

        7.   Representations of GI.   GI hereby represents and  warrants
   to Spyglass and the Subsidiary as follows:

             7.1  Organization and Standing.   GI is a corporation  duly
   organized, validly existing and  in good standing  under the laws  of
   the State of Delaware.

             7.2  Authorization of Transaction.   GI  has all  requisite
   power and  authority to  execute and  deliver this  Agreement and  to
   perform its obligations  hereunder.   The execution  and delivery  of
   this Agreement  by  GI  and  the  consummation  of  the  transactions
   contemplated hereby by GI  have been duly  and validly authorized  by
   all necessary corporate action on the part of GI.  This Agreement has
   been duly and validly executed and delivered by GI and constitutes  a
      
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<PAGE>                                    
   valid and  binding  obligation  of  GI,  enforceable  against  it  in
   accordance with its terms.

             7.3  Noncontravention.  Neither the execution and  delivery
   of  this  Agreement  by  GI,  nor  the  consummation  by  GI  of  the
   transactions contemplated hereby, (a) conflicts with or violates  any
   provision of the Certificate of Incorporation  or By-laws of GI,  (b)
   requires on the part of GI any filing with, or permit, authorization,
   consent or approval of, any governmental entity, (c) conflicts  with,
   results in breach of,  constitutes a default  under, or requires  any
   notice, consent or  waiver under,  any contract,  agreement or  other
   instrument to which GI is a party or by which it is bound (other than
   any consent  or  waiver which  has  already been  obtained),  or  (d)
   violates any  order,  writ,  injunction,  decree,  statute,  rule  or
   regulation applicable to GI.

        8.   Miscellaneous.

             8.1  Successors and  Assigns.   No  Party may  assign  this
   Agreement or any of its rights  or obligations hereunder without  the
   prior written consent of the other Parties, except (i) to the limited
   extent permitted  by Section  3.4  or (ii) as  part  of the  sale  or
   transfer of all or substantially all of the business, stock or assets
   of Spyglass or GI.  This Agreement, and the rights and obligations of
   the Parties hereunder,  shall be  binding upon  their successors  and
   permitted assigns.

             8.2  Confidentiality.    GI  agrees   that  it  will   keep
   confidential and  will  not  disclose or  divulge  any  confidential,
   proprietary or secret information which  GI may obtain from  Spyglass
   or the Subsidiary pursuant to this Agreement, unless such information
   is known, or  until such information  becomes known,  to the  public;
   provided, however, that GI may disclose  such information (i) to  its
   attorneys, accountants, consultants  and other  professionals to  the
   extent necessary  to obtain  their services  in connection  with  its
   investment in Spyglass or the Subsidiary, or (ii) to any Affiliate of
   GI; subject to the agreement of  such party to keep such  information
   confidential as set forth herein.   Spyglass and the Subsidiary  each
   agree that  they will  keep confidential  and  will not  disclose  or
   divulge any  confidential, proprietary  or secret  information  which
   they may  obtain from  GI pursuant  to  this Agreement,  unless  such
   information is known, or until such information becomes known, to the
   public; provided,  however,  that  Spyglass and  the  Subsidiary  may
   disclose  such  information  (i)  to  their  attorneys,  accountants,
   consultants and other professionals to the extent necessary to obtain
   their services  in connection  with this  Agreement, or  (ii) to  any
   Affiliate of Spyglass or the Subsidiary; subject to the agreement  of
   such party to keep such information confidential as set forth herein.

             8.3  Survival of Representations, Warranties and Covenants.
    All representations and  warranties contained  herein shall  survive

                                  10
<PAGE>                                    
   the execution  and delivery  of this  Agreement  and continue  for  a
   period  of  two  years  thereafter.    All  covenants  shall  survive
   indefinitely, except as limited in accordance with their terms.

             8.4  Notices.  All notices,  requests, consents, and  other
   communications under this Agreement  shall be in  writing and in  the
   English language, and shall be delivered by any lawful means, to  the
   following address:

        If to  Spyglass  or  the  Subsidiary,  at  Spyglass,  Inc.,  One
   Cambridge  Center,  Cambridge,  Massachusetts    02142,  Attn:  Chief
   Financial Officer, or at such other address or addresses as may  have
   been furnished in writing by Spyglass to GI; or

        If to GI, at 101 Tournament Drive, Horsham, Pennsylvania  19044,
   Attn: Executive Vice President, Business Development, with a copy  to
   the Senior  Vice President  and General  Counsel,  or at  such  other
   address or addresses as may have  been furnished in writing by GI  to
   Spyglass.

        Any such notices,  requests, consents  and other  communications
   shall be deemed delivered upon receipt by the addressee.

             8.5  Entire Agreement.  This Agreement embodies the  entire
   agreement and understanding among the Parties hereto with respect  to
   the subject matter  hereof and  supersedes all  prior agreements  and
   understandings relating to such subject matter.

             8.6  Amendments and Waivers.  Except as otherwise expressly
   set forth  in this  Agreement,  any term  of  this Agreement  may  be
   amended and  the observance  of any  term of  this Agreement  may  be
   waived (either  generally  or in  a  particular instance  and  either
   retroactively  or  prospectively),  with   the  written  consent   of
   Spyglass, the Subsidiary and GI.  No waivers of or exceptions to  any
   term, condition or provision  of this Agreement, in  any one or  more
   instances, shall  be deemed  to be,  or construed  as, a  further  or
   continuing waiver of any such term, condition or provision.

             8.7  Counterparts.  This Agreement  may be executed in  one
   or more  counterparts,  each  of  which shall  be  deemed  to  be  an
   original, but all of which shall be one and the same document.

             8.8  Severability.  The  invalidity or unenforceability  of
   any provision  of this  Agreement shall  not affect  the validity  or
   enforceability of any other provision of this Agreement.

             8.9  Costs and Expenses.   Except as specifically  provided
   otherwise in  this  Agreement,  all  costs  and  expenses  (including
   without limitation fees and expenses of attorneys, brokers, agents or
   finders) incurred by any Party in connection with this Agreement  and
      
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<PAGE>                                    
   the transactions  contemplated  hereby shall  be  paid by  the  party
   incurring such costs and expenses.

             8.10 Titles.  The  section headings of  this Agreement  are
   for convenience  of reference  only and  shall not  be considered  in
   construing this Agreement.

             8.11 Cooperation.   Each Party  shall, at  the request  and
   expense of  the  other Party,  at  any time  and  from time  to  time
   following the execution of this Agreement, execute and deliver to the
   other  Party  such   further  instruments  and   take  such   further
   administrative and ministerial actions as may be reasonably necessary
   or  appropriate  to  carry  out  the  purposes  and  intent  of  this
   Agreement.

             8.12 No Third Party  Beneficiaries.   Nothing expressed  or
   implied in this Agreement  or shall be construed  to confer upon  any
   person or  entity,  other  than  the  Parties  and  their  respective
   successors and permitted assigns, any rights or remedies under or  in
   connection with this Agreement.

             8.13 Governing Law.   This Agreement shall  be governed  by
   and construed in accordance with the laws of the State of Delaware.



             [Remainder of Page Intentionally Left Blank]
<PAGE>

             IN WITNESS WHEREOF, the Parties have caused this  Agreement
   to be executed  by their duly  authorized representatives  as of  the
   Effective Date.


                                    SPYGLASS, INC.


                                    By:  /s/ Micahel F. Tyrrell

                                          (print name and title)
                                    Michael F. Tyrrell, E.V.P.
                                    Bus.Dev.


                                  
                                    SPYGLASS DSIC, INC.


                                    By:  /s/ Michael F. Tyrrell

                                    Michael F. Tyrrell, E.V.P.
                                          (print name and title)


                                    GENERAL INSTRUMENT CORPORATION


                                    By:   /s/ Richard C. Smith


                                    Richard C. Smith
                                          (print name and title)

<PAGE>
                                                               Exhibit C


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