Callable Warrant

NEITHER THESE  SECURITIES  NOR THE  SECURITIES  INTO WHICH THESE  SECURITIES ARE
EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE  COMMISSION OR
THE  SECURITIES  COMMISSION  OF ANY STATE IN  RELIANCE  UPON AN  EXEMPTION  FROM
REGISTRATION  UNDER THE  SECURITIES  ACT OF 1933,  AS AMENDED  (THE  "SECURITIES
ACT"),  AND,  ACCORDINGLY,  MAY NOT BE OFFERED  OR SOLD  EXCEPT  PURSUANT  TO AN
EFFECTIVE  REGISTRATION  STATEMENT  UNDER THE  SECURITIES  ACT OR PURSUANT TO AN
AVAILABLE  EXEMPTION  FROM  THE  REGISTRATION  REQUIREMENTS  THEREUNDER  AND  IN
COMPLIANCE WITH APPLICABLE STATE SECURITIES OR BLUE SKY LAWS.

                                          GENERAL DATACOMM INDUSTRIES, INC.


                                     WARRANT

Warrant No.                                              Dated  July 31, 2000


         General  DataComm   Industries,   Inc.,  a  Delaware  corporation  (the
"Company"), hereby certifies that, for value received, or its registered assigns
("Holder"), is entitled,  subject to the terms set forth below, to purchase from
the  Company a total of shares of common  stock,  $.10 par value per share  (the
"Common Stock"), of the Company (each such share, a "Warrant Share" and all such
shares,  the "Warrant Shares") at an exercise price equal to $5.75 per share (as
adjusted from time to time as provided in Section 9, the "Exercise  Price"),  at
any time and from time to time from and after the date  hereof and  through  and
including July 31, 2005 (the  "Expiration  Date"),  and subject to the following
terms and conditions:

                  1.  Registration  of Warrant.  The Company shall register this
Warrant,  upon  records to be  maintained  by the Company for that  purpose (the
"Warrant Register"),  in the name of the record Holder hereof from time to time.
The  Company  may deem and treat the  registered  Holder of this  Warrant as the
absolute owner hereof for the purpose of any exercise hereof or any distribution
to the Holder, and for all other purposes, and the Company shall not be affected
by notice to the contrary except in compliance with Section 2 hereof.

<PAGE>

                  2.       Registration of Transfers and Exchanges.

                           (a)      The Company  shall  register the  transfer
of any portion of this Warrant in the Warrant  Register,  upon surrender of this
Warrant,  with the Form of Assignment attached hereto duly completed and signed,
to the  Company at the office  specified  in or pursuant to Section 13. Upon any
such  registration  or  transfer,  a new warrant to purchase  Common  Stock,  in
substantially the form of this Warrant (any such new warrant,  a "New Warrant"),
evidencing  the portion of this  Warrant so  transferred  shall be issued to the
transferee and a New Warrant  evidencing  the remaining  portion of this Warrant
not so  transferred,  if any, shall be issued to the  transferring  Holder.  The
acceptance  of the New  Warrant by the  transferee  thereof  shall be deemed the
acceptance by such  transferee of all of the rights and  obligations of a holder
of a Warrant.

                           (b)      This Warrant is exchangeable  upon the
surrender  hereof by the Holder to the  office of the  Company  specified  in or
pursuant to Section 13 for one or more New Warrants, evidencing in the aggregate
the right to purchase  the number of Warrant  Shares which may then be purchased
hereunder. Any such New Warrant will be dated the date of such exchange.

                  3.       Duration, Exercise and Redemption of Warrants.

                           (a)      This Warrant shall be exercisable  by the
registered  Holder on any business day before 5:30 P.M.,  New York City time, at
any time and from time to time on or after the date hereof to and  including the
Expiration  Date. At 5:30 P.M., New York City time on the  Expiration  Date, the
portion of this Warrant not exercised prior thereto shall be and become void and
of no value.

                           (b)      Subject to  Sections  2(b) and 10, upon
surrender of this Warrant, with the Form of Election to Purchase attached hereto
duly completed and signed, to the Company at its address for notice set forth in
Section 13, and upon payment of the Exercise  Price  multiplied by the number of
Warrant  Shares  that the Holder  intends to purchase  hereunder,  in the manner
provided  hereunder,  all as  specified by the Holder in the Form of Election to
Purchase,  the Company shall promptly (but in no event later than 5 Trading Days
(as defined in the Securities  Purchase  Agreement dated July 31, 2000 after the
Date of Exercise (as defined herein) issue or cause to be issued and cause to be
delivered  to or upon the written  order of the Holder and in such name or names
as the Holder may designate,  a certificate for the Warrant Shares issuable upon
such exercise, free of restrictive legends except (i) either in the event that a
registration  statement covering the resale of the Warrant Shares and naming the
Holder as a selling stockholder  thereunder is not then effective or the Warrant
Shares are not freely transferable without volume restrictions  pursuant to Rule
144(k) promulgated under the Securities Act of 1933, as amended (the "Securities
Act"),  or (ii) if this  Warrant  shall have been  issued  pursuant to a written
agreement  between  the  original  Holder and the  Company,  as required by such
agreement.  Any person so  designated  by the Holder to receive  Warrant  Shares
shall be deemed to have become holder of record of such Warrant Shares as of the
Date of Exercise of this Warrant.

                                       2
<PAGE>

                           A "Date of  Exercise"  means  the  date on which  the
Company shall have received (i) this Warrant (or any New

Warrant,  as applicable),  with the Form of Election to Purchase attached hereto
(or attached to such New Warrant)  appropriately  completed and duly signed, and
(ii) payment of the Exercise Price for the number of Warrant Shares so indicated
by the holder hereof to be purchased.

                           (c)      This Warrant shall be  exercisable,  either
in its  entirety  or, from time to time,  for a portion of the number of Warrant
Shares. If less than all of the Warrant Shares which may be purchased under this
Warrant  are  exercised  at any time,  the  Company  shall  issue or cause to be
issued,  at its  expense,  a New Warrant  evidencing  the right to purchase  the
remaining  number of Warrant  Shares for which no exercise has been evidenced by
this Warrant.

                           (d)      Commencing at any time after the date the
Securities and Exchange Commission declares effective the registration statement
covering  the  resale of the  Warrant  Shares  and  naming the Holder as selling
stockholder  thereunder,  but no earlier  than July 31,  2002 if (i) the average
closing bid price of the Common  Stock on the New York Stock  Exchange  (or such
other national  securities  exchange on which the Common Stock is then listed or
quoted for trading) for any 20 trading days during a 30 consecutive  Trading Day
period exceeds 200% of the Exercise Price (a "Trigger Period"),  and (ii) during
the  Trigger  Period and up to and  including  the  Redemption  Date (as defined
herein),  the Warrant  Shares are either  registered  for resale  pursuant to an
effective  registration  statement  naming the  Holder as a selling  stockholder
thereunder or freely transferable  without volume restrictions  pursuant to Rule
144(k)  promulgated  under the  Securities  Act, as determined by counsel to the
Company pursuant to a written opinion letter addressed and in form and substance
acceptable to the Holder and the transfer  agent for the Common Stock,  then the
Company shall have the right, upon ten (10) days' notice to the Holder given not
later than five (5) Trading Days after the conclusion of any such Trigger Period
(the "Redemption  Notice"),  to redeem 100% of the total Warrant Shares issuable
under  this  Warrant  as such  number  may be  adjusted,  at a price of $.01 per
Warrant Share (the "Redemption  Price"), on the date set forth in the Redemption
Notice,  but in no event  earlier than ten (10) days  following  the date of the
receipt by the Holder of the  Redemption  Notice (the  "Redemption  Date").  The
Holder may exercise this Warrant at any time prior to the  Redemption  Date. Any
portion of this Warrant not  exercised by 5:30 p.m.  (New York City time) on the
Redemption  Date shall no longer be  exercisable  and shall be  returned  to the
Company,  and the Company,  upon its receipt of the unexercised  portion of this
Warrant,  shall  issue  therefor  in  full  and  complete  satisfaction  of  its
obligations under such remaining portion of this Warrant to the Holder an amount
equal to the number of shares of Common Stock then issuable hereunder multiplied
by the Redemption  Price. The Redemption Price shall be mailed to such Holder at
its address of record, and the Warrant shall be canceled.

                  4. Registration  Rights.  The Warrant Shares issuable pursuant
to the exercise of this Warrant shall be entitled to the registration rights set
forth in the  Registration

                                       3
<PAGE>

Rights  Agreement  dated July 31,  2000 to which the  Company  and the  original
Holder are parties (the "Registration Rights Agreement").

                  5.       [Intentionally left blank]

                  6.  Payment of Taxes.  The  Company  will pay all  documentary
stamp taxes  attributable to the issuance of Warrant Shares upon the exercise of
this Warrant;  provided,  however, that the Company shall not be required to pay
any tax  which  may be  payable  in  respect  of any  transfer  involved  in the
registration of any  certificates for Warrant Shares or Warrants in a name other
than that of the  Holder.  The  Holder  shall be  responsible  for all other tax
liability that may arise as a result of holding or transferring  this Warrant or
receiving Warrant Shares upon exercise hereof.

                  7. Replacement of Warrant. If this Warrant is mutilated, lost,
stolen or  destroyed,  the Company shall issue or cause to be issued in exchange
and  substitution  for  and  upon  cancellation   hereof,  or  in  lieu  of  and
substitution for this Warrant, a New Warrant,  but only upon receipt of evidence
reasonably  satisfactory  to the Company of such loss,  theft or destruction and
indemnity, if requested,  satisfactory to it. Applicants for a New Warrant under
such circumstances shall also comply with such other reasonable  regulations and
procedures and pay such other reasonable charges as the Company may prescribe.

                  8. Reservation of Warrant Shares.  The Company  covenants that
it will at all times  reserve and keep  available  out of the  aggregate  of its
authorized but unissued  Common Stock,  solely for the purpose of enabling it to
issue  Warrant  Shares upon  exercise of this  Warrant as herein  provided,  the
number of  Warrant  Shares  which are then  issuable  and  deliverable  upon the
exercise of this entire Warrant, free from preemptive rights or any other actual
contingent purchase rights of persons other than the Holder (taking into account
the adjustments and  restrictions of Section 9). The Company  covenants that all
Warrant Shares that shall be so issuable and  deliverable  shall,  upon issuance
and the payment of the applicable  Exercise  Price in accordance  with the terms
hereof, be duly and validly authorized, issued and fully paid and nonassessable.

                  9.  Certain  Adjustments.  The  Exercise  Price and  number of
Warrant Shares  issuable upon exercise of this Warrant are subject to adjustment
from time to time as set forth in this Section. Upon each such adjustment of the
Exercise Price pursuant to this Section,  the Holder shall  thereafter  prior to
the Expiration  Date be entitled to purchase,  at the Exercise  Price  resulting
from such  adjustment,  the number of Warrant Shares obtained by multiplying the
Exercise Price in effect  immediately  prior to such adjustment by the number of
Warrant Shares issuable upon exercise of this Warrant  immediately prior to such
adjustment and dividing the product thereof by the Exercise Price resulting from
such adjustment. Any adjustment to the number of Warrant Shares shall apply only
to the Warrant Shares for which this Warrant has not been exercised.

                            (a)     If the Company,  at any time while this
Warrant is  outstanding  shall,  (i) pay a stock  dividend to all holders of its
Common Stock or otherwise make a

                                       4
<PAGE>

distribution  or  distributions  of Common Stock to holders of its Common Stock,
(ii)  subdivide  outstanding  shares of  Common  Stock  into a larger  number of
shares,  or (iii)  combine  outstanding  shares of Common  Stock  into a smaller
number of shares,  the Exercise Price shall be multiplied by a fraction of which
the numerator shall be the number of shares of Common Stock (excluding  treasury
shares, if any) outstanding before such event and of which the denominator shall
be the number of shares of Common  Stock  (excluding  treasury  shares,  if any)
outstanding after such event. Any adjustment made pursuant to this Section shall
become  effective  immediately  after the record date for the  determination  of
stockholders  entitled to receive such dividend or distribution and shall become
effective  immediately  after the effective date in the case of a subdivision or
combination, and shall apply to successive subdivisions and combinations.

                           (b)      In case of any  reclassification  of the
Common Stock or any compulsory share exchange pursuant to which the Common Stock
is converted into other securities, cash or property, then the Holder shall have
the right  thereafter to exercise this Warrant only into the shares of stock and
other  securities,  cash and  property  receivable  upon or deemed to be held by
holders of Common Stock following such  reclassification or share exchange,  and
the Holder,  upon exercise of this Warrant,  shall be entitled by reason of such
event to receive such amount of securities, cash or property equal to the amount
of Warrant  Shares  such  Holder  would have been  entitled  to had such  Holder
exercised  this  Warrant  immediately  prior to such  reclassification  or share
exchange.  This provision shall apply to successive  reclassifications  or share
exchanges.

                            (c)     [Intentionally left blank]

                           (d)      In case of any merger or consolidation of
the Company with or into another Person (as defined in the  Securities  Purchase
Agreement dated July 31, 2000) or sale of all or substantially all of the assets
of the Company,  then the Holder shall have the right  thereafter in the case of
such merger or consolidation  or sale of all or substantially  all of the assets
of the Company to receive upon the exercise of this Warrant, the same number and
kind of shares of stock or the same amount of property, cash or securities as it
would have been entitled to receive upon the  occurrence of any such event as if
it had been immediately prior to such event, the holder of the number of Warrant
Shares then exercisable under this Warrant.

                           (e)      For the purposes of this Section 9, the
following clauses shall also be applicable:

                                    (i) Record  Date.  In case the Company
shall  take a record of the  holders  of its  Common  Stock for the  purpose  of
entitling them to receive a stock  dividend,  then such record date shall be the
date of the issue of the  shares of Common  Stock to have been  issued  upon the
declaration of such dividend.

                                    (ii)  Treasury  Shares. The number of shares
of Common Stock  outstanding at any given time shall not include shares owned or
held by or for the  account  of

                                       5
<PAGE>

the Company, and the disposition of any such shares shall be considered an issue
or sale of Common Stock.

                           (f)     All  calculations  under this Section 9 shall
be made to the nearest cent or the nearest  1/100th of a share,  as the case may
be.

                            (g) If (i) the Company shall declare a dividend
(or any other  distribution)  on its Common  Stock;  or (ii) the  Company  shall
declare a special  nonrecurring  cash  dividend on or a redemption of its Common
Stock;  or (iii) the Company shall  authorize the granting to all holders of the
Common  Stock  rights or warrants  to  subscribe  for or purchase  any shares of
capital  stock  of any  class or of any  rights;  or (iv)  the  approval  of any
stockholders   of  the  Company  shall  be  required  in  connection   with  any
reclassification  of the Common Stock, any  consolidation or merger to which the
Company is a party,  any sale or  transfer  of all or  substantially  all of the
assets of the Company, or any compulsory share exchange whereby the Common Stock
is converted into other securities,  cash or property;  or (v) the Company shall
authorize the voluntary dissolution, liquidation or winding up of the affairs of
the Company,  then the Company  shall cause to be mailed to each Holder at their
last  addresses  as they shall  appear  upon the Warrant  Register,  at least 10
calendar  days prior to the  applicable  record or  effective  date  hereinafter
specified,  a notice  stating  (x) the date on which a record is to be taken for
the purpose of such dividend,  distribution,  redemption, rights or warrants, or
if a record is not to be taken, the date as of which the holders of Common Stock
of record to be entitled to such dividend, distributions,  redemption, rights or
warrants are to be  determined  or (y) the date on which such  reclassification,
consolidation,  merger,  sale,  transfer or share exchange is expected to become
effective  or close,  and the date as of which it is  expected  that  holders of
Common  Stock of record  shall be entitled to  exchange  their  shares of Common
Stock  for   securities,   cash  or  other   property   deliverable   upon  such
reclassification,   consolidation,   merger,  sale,  transfer,  share  exchange,
dissolution,  liquidation or winding up; provided,  however, that the failure to
mail such  notice or any defect  therein  or in the  mailing  thereof  shall not
affect the  validity of the  corporate  action  required to be specified in such
notice.

                  10.      Payment of Exercise Price.  The Holder shall pay the
Exercise Price in one of the following manners:

                           (a)      Cash Exercise.  The Holder may deliver
immediately available funds; or
                           (b)      Cashless  Exercise.  At any time after the
earlier  to occur of the  Effectiveness  Date (as  defined  in the  Registration
Rights Agreement) and the date the initial registration statement filed pursuant
to the Registration  Rights  Agreement is declared  effective by the Commission,
when a  registration  statement  covering  the resale of the Warrant  Shares and
naming the Holder as a selling stockholder thereunder is not then effective, and
the Holder is unable to sell the  Warrant  Shares  without  volume  restrictions
under Rule 144(k), the Holder may surrender this Warrant to the Company together
with a notice of cashless exercise, in

                                       6
<PAGE>

which event the Company shall issue to the Holder the number of Warrant Shares
determined as follows:

                  X = Y (A-B)/A

         where:
                  X = the number of Warrant Shares to be issued to the Holder.

                  Y = the number of Warrant Shares with respect to which this
                      Warrant is being exercised.

                  A = the average of the  closing  sale prices of the  Common
                      Stock for the  fifteen (15) consecutive Trading Days
                      immediately  prior to (but not including) the Date of
                      Exercise.

                  B = the Exercise Price.

For purposes of Rule 144  promulgated  under the Securities Act, it is intended,
understood  and  acknowledged  that the  Warrant  Shares  issued  in a  cashless
exercise  transaction  shall be deemed to have been acquired by the Holder,  and
the  holding  period  for the  Warrant  Shares  shall  be  deemed  to have  been
commenced, on the issue date.

                  11. Certain Exercise  Restrictions.  A Holder may not exercise
this Warrant to the extent such  exercise  would result in the Holder,  together
with any affiliate  thereof,  beneficially  owning (as  determined in accordance
with  Section  13(d)  of the  Securities  Exchange  Act  of  1934,  as  amended,
("Exchange  Act") and the rules  promulgated  thereunder) in excess of 9.999% of
the then issued and  outstanding  shares of Common  Stock,  including  shares of
Common  Stock  issuable  upon  such  exercise  and  held  by such  Holder  after
application of this Section. Since the Holder will not be obligated to report to
the Company  the number of shares of Common  Stock it may hold at the time of an
exercise hereunder, unless the exercise at issue by itself alone would result in
the  issuance  of  shares  of  Common  Stock in  excess  of  9.999%  of the then
outstanding  shares of Common Stock without regard to any other shares of Common
Stock which may be beneficially owned by the Holder or an affiliate thereof, the
Holder  shall  have the  authority  and  obligation  to  determine  whether  the
restriction  contained  in this  Section  will  limit  any  particular  exercise
hereunder  and to the extent  that the  Holder  determines  that the  limitation
contained in this Section  applies,  the  determination of which portion of this
Warrant is exercisable shall be the responsibility and obligation of the Holder.
If the Holder has  delivered  a Form of  Election  to  Purchase  for a number of
Warrant  Shares that by itself  alone would  result in the issuance in excess of
9.999% of the then  outstanding  shares of Common  Stock  without  regard to any
other shares of Common Stock which may be beneficially owned by the Holder or an
affiliate  thereof,  the Company  shall notify the Holder of this fact and shall
honor the  exercise  for the maximum  portion of this  Warrant  permitted  to be
exercised  on such Date of Exercise  in  accordance  with the periods  described
herein and  disregard  the balance of such Form of Election to  Purchase,  as if
never  delivered.  The provisions of this Section may be waived by a Holder (but
only as to itself and not to any other  Holder) upon not less than 61 days prior
notice to the Company. Other Holders shall be

                                       7
<PAGE>

unaffected  by any such  waiver.  The Company  shall not be liable in damages or
otherwise for any failure to so notify the Holder.

                  12.  Fractional  Shares.  The Company shall not be required to
issue or cause to be issued  fractional  Warrant  Shares on the exercise of this
Warrant.  The number of full  Warrant  Shares  which shall be issuable  upon the
exercise of this Warrant shall be computed on the basis of the aggregate  number
of Warrant Shares  purchasable on exercise of this Warrant so presented.  If any
fraction of a Warrant Share would, except for the provisions of this Section, be
issuable on the  exercise of this  Warrant,  the Company  shall pay an amount in
cash equal to the Exercise Price multiplied by such fraction.

                  13. Notices.  Any and all notices or other  communications  or
deliveries hereunder shall be in writing and shall be deemed given and effective
on the earliest of (i) the date of transmission, if such notice or communication
is delivered via facsimile at the facsimile  telephone  number specified in this
Section  prior to 5:30 p.m.  (New York City  time) on a business  day,  (ii) the
business day after the date of transmission,  if such notice or communication is
delivered  via  facsimile at the facsimile  telephone  number  specified in this
Section at or later than 5:30 p.m.  (New York City time) on any date and earlier
than  11:59  p.m.  (New York City time) on such  date,  (iii) the  business  day
following  the  date of  mailing,  if sent by  nationally  recognized  overnight
courier service, or (iv) upon actual receipt by the party to whom such notice is
required to be given. The addresses for such communications  shall be: (i) if to
the  Company,  to  Park  Road  Extension,  Middlebury,  Connecticut  06762-1299;
facsimile number (203) 577-6244,  attention Chief Financial Officer,  or (ii) if
to the Holder, to the Holder at the address or facsimile number appearing on the
Warrant  Register or such other  address or  facsimile  number as the Holder may
provide to the Company in accordance with this Section.

                  14.  Warrant  Agent.  The Company shall serve as warrant agent
under this Warrant. Upon thirty (30) days' notice to the Holder, the Company may
appoint a new warrant agent.  Any corporation  into which the Company or any new
warrant agent may be merged or any corporation  resulting from any consolidation
to  which  the  Company  or any  new  warrant  agent  shall  be a  party  or any
corporation   to  which  the  Company  or  any  new  warrant   agent   transfers
substantially all of its corporate trust or shareholders services business shall
be a successor  warrant  agent under this  Warrant  without any further act. Any
such  successor  warrant agent shall  promptly cause notice of its succession as
warrant agent to be mailed (by first class mail,  postage prepaid) to the Holder
at the Holder's last address as shown on the Warrant Register.

                  15.      Miscellaneous.

                           (a)      This  Warrant  shall be  binding  on and
inure to the benefit of the parties hereto and their  respective  successors and
assigns.  This Warrant may be amended only in writing  signed by the Company and
the Holder and their successors and assigns.

                                       8
<PAGE>

                           (b)      Subject to Section 15(a),  above,  nothing
in this Warrant  shall be construed to give to any person or  corporation  other
than the Company and the Holder any legal or  equitable  right,  remedy or cause
under this Warrant.  This Warrant shall inure to the sole and exclusive  benefit
of the Company and the Holder.

                           (c)      The corporate laws of the State of Delaware
shall govern all issues  concerning  the relative  rights of the Company and its
stockholders.  All  other  questions  concerning  the  construction,   validity,
enforcement  and  interpretation  of  this  Warrant  shall  be  governed  by and
construed and enforced in accordance  with the internal laws of the State of New
York, without regard to the principles of conflicts of law thereof.  The Company
and the Holder hereby  irrevocably  submit to the exclusive  jurisdiction of the
state and federal courts sitting in the City of New York,  borough of Manhattan,
for the adjudication of any dispute hereunder or in connection  herewith or with
any transaction  contemplated hereby or discussed herein, and hereby irrevocably
waives,  and agrees not to assert in any suit,  action or proceeding,  any claim
that it is not personally subject to the jurisdiction of any such court, or that
such suit, action or proceeding is improper.  Each of the Company and the Holder
hereby  irrevocably  waives personal  service of process and consents to process
being served in any such suit,  action or proceeding by receiving a copy thereof
sent to the  Company  at the  address  in effect  for  notices  to it under this
instrument  and agrees that such service shall  constitute  good and  sufficient
service of process and notice thereof.  Nothing contained herein shall be deemed
to limit in any way any right to serve process in any manner permitted by law.

                           (d)      The headings  herein are for  convenience
only, do not  constitute a part of this Warrant and shall not be deemed to limit
or affect any of the provisions hereof.

                           (e)      In case any one or more of the provisions
of this Warrant shall be invalid or unenforceable  in any respect,  the validity
and  enforceability  of the remaining terms and provisions of this Warrant shall
not in any way be affected or impaired  thereby and the parties  will attempt in
good  faith to agree upon a valid and  enforceable  provision  which  shall be a
commercially  reasonable  substitute  therefor,  and  upon  so  agreeing,  shall
incorporate such substitute provision in this Warrant.

                           (f)      The Holder of this  Warrant  shall  have no
rights as a stockholder  of the Company in respect of Warrant Shares as to which
this Warrant shall not have been exercised and payment made as herein provided.

                           (g)  The Holder of this Warrant is subject to certain
trading and other limitations  contained in of the Securities Purchase Agreement
of the Company dated as of July 31, 2000.

                  16. A Holder may not exercise  this Warrant to the extent such
exercise  would  result in the  Holder,  together  with any  affiliate  thereof,
beneficially  owning (as  determined  in  accordance  with Section  13(d) of the
Exchange Act and the rules  promulgated  thereunder)  in excess of 4.999% of the
then issued and outstanding  shares of Common Stock,  including shares of Common
Stock  issuable upon such exercise and held by such Holder after

                                       9
<PAGE>

application of this Section. Since the Holder will not be obligated to report to
the Company  the number of shares of Common  Stock it may hold at the time of an
exercise hereunder, unless the exercise at issue would result in the issuance of
shares of Common  Stock in  excess of 4.999% of the then  outstanding  shares of
Common  Stock  without  regard to any other  shares of Common Stock which may be
beneficially owned by the Holder or an affiliate thereof,  the Holder shall have
the authority and obligation to determine  whether the restriction  contained in
this Section will limit any particular exercise hereunder and to the extent that
the Holder determines that the limitation contained in this Section applies, the
determination  of which  portion  of this  Warrant is  exercisable  shall be the
responsibility  and obligation of the Holder. If the Holder has delivered a Form
of Election to Purchase for a number of Warrant  Shares that would result in the
issuance  in excess of the  permitted  amount  hereunder,  and the Company is so
aware of such result, the Company shall notify the Holder of this fact and shall
honor the  exercise  for the maximum  portion of this  Warrant  permitted  to be
exercised  on such Date of Exercise  in  accordance  with the periods  described
herein and  disregard  the balance of such Form of Election to  purchase,  as if
never  delivered.  The provisions of this Section may be waived by a Holder (but
only as to itself and not to any other Holder) upon not less than 61 days' prior
notice to the Company. Other Holders shall be unaffected by any such waiver. The
Company shall not be liable in damages or otherwise for any failure to so notify
the Holder.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK,
                             SIGNATURE PAGE FOLLOWS]

                                       10
<PAGE>


                  IN WITNESS WHEREOF,  the Company has caused this Warrant to be
duly executed by its authorized officer as of the date first indicated above.

                                    GENERAL DATACOMM INDUSTRIES, INC.

                                    By: /S/ WILLIAM G. HENRY
                                    Name: William G. Henry
                                    Title:  Vice President, Finance

                                       11

<PAGE>



                          FORM OF ELECTION TO PURCHASE

(To be executed by the Holder to exercise the right to purchase shares of Common
Stock under the foregoing Warrant)

To General DataComm Industries, Inc.:

         In accordance  with the Warrant  enclosed with this Form of Election to
Purchase,  the undersigned hereby  irrevocably elects to purchase  _____________
shares  of  common  stock,  $.10  par  value  per  share,  of  General  DataComm
Industries,  Inc. (the "Common Stock") and , if such Holder is not utilizing the
cashless  exercise  provisions  set  forth in this  Warrant,  encloses  herewith
$________  in cash,  certified  or  official  bank  check or  checks,  which sum
represents  the  aggregate  Exercise  Price (as defined in the  Warrant) for the
number of shares of Common  Stock to which  this Form of  Election  to  Purchase
relates,  together with any applicable taxes payable by the undersigned pursuant
to the Warrant.

         The  undersigned  requests that  certificates  for the shares of Common
Stock issuable upon this exercise be issued in the name of

                        PLEASE INSERT SOCIAL SECURITY OR
                            TAX IDENTIFICATION NUMBER




                         (Please print name and address)


         If the number of shares of Common  Stock  issuable  upon this  exercise
shall not be all of the shares of Common Stock which the undersigned is entitled
to purchase in accordance with the enclosed  Warrant,  the undersigned  requests
that a New Warrant (as defined in the Warrant)  evidencing the right to purchase
the shares of Common  Stock not  issuable  pursuant  to the  exercise  evidenced
hereby be issued in the name of and delivered to:

                                           (Please print name and address)





Dated:            ,                 Name of Holder:


                                   (Print)
                                   (By:)
                                   (Name:)
                                   (Title:)
                                   (Signature  must  conform in all  respects
                                    to name of holder as specified
                                    on the face of the Warrant)

                                       12
<PAGE>




                               FORM OF ASSIGNMENT

           [To be completed and signed only upon transfer of Warrant]

         FOR VALUE RECEIVED, the undersigned hereby sells, assigns and transfers
unto  ________________________________  the  right  represented  by  the  within
Warrant to  purchase  ____________  shares of Common  Stock of General  DataComm
Industries,   Inc.   to  which  the  within   Warrant   relates   and   appoints
________________  attorney  to  transfer  said  right on the  books  of  General
DataComm Industries, Inc. with full power of substitution in the premises.

Dated:

---------------, ----


                             ---------------------------------------
                            (Signature  must  conform in all respects to name of
                             holder as specified on the face of the Warrant)


                             ---------------------------------------
                                  Address of Transferee
                             ---------------------------------------

                              ---------------------------------------

In the presence of:


--------------------------

                                       13