<PAGE>   1
                                                                   EXHIBIT 10.3

                      MARFIELD, BELGARDE & YAFFE COMPANIES
                               MANAGED PROPERTIES
                         OFFICE/SERVICE BUILDING LEASE

This LEASE is made this 15th day of August 1996, between 94th Street Associates
(as LANDLORD) and Ringer Corporation (as TENANT).

                                  WITNESSETH:
                                  -----------

In consideration of the mutual covenants, promises, and agreements herein
contained, the parties agree as follows:

1. DESCRIPTION OF THE PREMISES

TENANT hereby leases from LANDLORD certain Premises (Leased Premises) within
the building (Building), identified as 9555 James Ave. S., Bloomington MN. The
Lease Premises is identified on the building plans as Suite 200 and is more
specifically designated in Building Floor Plan (Exhibit "A") and Detailed Floor
Plan (Exhibit "B") which are made a part hereof. The Lease Premises is measured
from the outside of all exterior walls to the center of tenant division and
common area walls. The Leased Premises contain:

        Office, Restroom, entry and finished spaces             4,851 S.F.
        Storage or service area                                 1,589 S.F.
                Total Area                                      6,440 S.F.

2. RENT

TENANT covenants to pay annual Base Rent for the Leased Premises of Forty One
Thousand Five Hundred Thirty-Eight and no/100 ($41,538.00) payable to the
LANDLORD, or to any other entity designated by LANDLORD, without further
notice, in equal monthly installments, subject to proration in the case of the
first and last months of the Lease term, of $3,461.50 on the first business day
of each month during the full term hereof. See Section 7 for TENANT's
Additional Rent obligations. TENANT's obligation to pay Base and Additional
Rent is unconditional and independent of any other provision of this Lease.
TENANT agrees not to withhold Base and Additional Rent for any reason. TENANT
agrees to pay a ten percent (10%) late charge fee each month on any sums due
LANDLORD which are owing to the LANDLORD by the tenth day of that month. The
first month's Base Rent is included with this Lease as Check #052767 dated
8/19/96 $3,461.50, issued by Ringer Corporation.

Notwithstanding the foregoing, the granting of any rent abatement, above
standard leaseholds, or other concessions is conditioned upon TENANT fulfilling
all its obligations under the Lease, all Rent previously abated and other
concessions granted shall be immediately paid to the Landlord.

3. TERM OF LEASE

Tenant shall be given occupancy upon issuance of "Certificate of Occupancy",
with rental abatement until October 14, 1996, with full rental payments to
begin October 15, 1996.

The Lease is 3 years 0 months commencing on the 1st day of October, 1996 and
expiring on the last day of September, 1999.


                                       1

<PAGE>   2

4. USE OF PREMISES

TENANT agrees to use the Leased Premises for office, warehouse, laboratory and
no other purpose; subject to all local, state, and federal laws regulating such
use. Such use shall not cause excessive odors, humidity, noise or vibrations
which may injure the building, cause harm to, or disrupt other tenants.

5. PARKING AND COMMON AREAS

The TENANT, its employees and invitees shall have the non-exclusive right to
use the common areas, driveways and parking lots along with the other tenants
of the Building and their employees and invitees. The use of common areas, and
the portion of the land set aside by LANDLORD for non-exclusive use of tenants,
is subject to such reasonable rules and regulations as the LANDLORD may impose
from time to time. No more than 24 parking spaces are to be occupied at any one
time by the TENANT, its employees and invitees. Overnight parking of vehicles
and the storage, at any time, of any other property in the common area 
is prohibited.

6. NET LEASE

This is a "net" Lease, and LANDLORD shall not be required to provide any
services or do any acts in connection with the Leased Premises not specifically
set forth in this Lease. As hereinafter further described in this Lease, the
TENANT is responsible for and shall pay its utility charges, trash removal,
interior cleaning and maintenance, its proportionate share of real estate taxes
including installments of assessments and its proportionate share of the
Building's operating expenses.

7. ADDITIONAL RENT

The net rentable area of the building(s) #9555 James in the project is/are
115,000 sq. ft.
and accordingly, the TENANT's proportionate share for purposes of allocating
real estate taxes and assessments and operating expenses is 5.6%.

8. REAL ESTATE TAXES

Real estate taxes include the following:

        (a) all real estate taxes

        (b) all installments of assessments, general or special, levied against
the property

9. OPERATING EXPENSES

Operating Expenses include the following:

        (a) City water and sewer charges, except where used by tenants in
            substantial amounts for production and is therefore separately
            metered, and the monitoring surveillance of the fire protection 
            system.


                                       2

<PAGE>   3
     (b) Lawn care, snow and liter removal, and the repair and maintenance as
         reasonably required for:  parking lots, drives, sidewalks, landscaped
         areas, roof, H.V.A.C. systems, garage doors and garage door openers,
         and exterior panes of exterior panes of exterior windows and foyer
         glass.

     (c) Electrical service for the trash room (if any) and mechanical rooms and
         for lighting, replacement of bulbs used for exterior lighting and trash
         removal from the common area trash room serving the TENANT, if any.

     (d) Insurance for fire and extended coverage, loss of rents and business
         interruption general liability. 

     (e) All other maintenance, replacement, repair and miscellaneous operating
         expenses except structural maintenance and that which is covered by
         manufacturer or subcontractor warranties.

     (f) Property management expenses of four percent of the Base Rents and
         Additional Rents collected.

     (g) Such other expenses incurred in operating the Building generally, if of
         a type normally incurred in the operating of similar buildings.

     (h) Maintenance of vestibules.

Commencing with the operating expenses incurred and real estate taxes payable in
the year this Lease commences and each subsequent year during the Lease term,
TENANT will pay, in equal monthly installments, payable in advance on the first
day of each calendar month, its estimated monthly proportionate share of all
such real estate taxes and operating expenses.  As the actual amount will not be
known at the beginning of each calendar year, LANDLORD shall make a reasonable
estimate, to the best of its knowledge, of what the amount will be for that
year, and TENANT will pay its estimated proportionate share each month.  In no
way should LANDLORD's estimate be construed as actuals or as a guarantee.

After the actual real estate tax statement is received, LANDLORD shall have the
right to make adjustments for any difference between that which TENANT has
paid and that which it should have paid.  TENANT shall then start paying its
proportionate share based upon the actual tax statement.

LANDLORD shall have the right to make adjustments periodically (but at least
annually) to the operating expenses, and adjust accordingly.  When actual
operating expenses have been compiled, a final year-end adjustment will be made,
and either a charge or credit will be issued.  LANDLORD agrees to exercise due
to care and diligence to obtain operating expenses, services and supplies at
competitive and reasonable market costs with acceptable quality and service
standards.





                                       3



<PAGE>   4



TENANT may have been given projections for real estate taxes by LANDLORD's
agents.  LANDLORD does not warrant that these projections are correct or that
they even approximate the amounts shown.  The TENANT is encouraged to call the
city assessor to verify the real estate tax projections before executing the
lease.



10.  UTILITIES

TENANT is responsible and shall pay for all of its utility services.  The TENANT
is separately metered for gas and electricity and will contract with the utility
companies for service requirements and billing.  TENANT is also responsible for
its own telephone service.

LANDLORD reserves the right to protect its Property and interest with respect to
utilities in any way it sees fit should TENANT not pay utility charges.

In the event the TENANT uses water and sewer in substantial amounts or for
production purposes, the LANDLORD shall install at TENANT's expense a water
meter to sub-meter for said water and sewer at rates as charged by the City.
TENANT shall pay to the City any water availability charge (WAC) and sewer
availability charge high usage.

LANDLORD shall, under no circumstances, be liable for; a) physical loss
arising from any failure  to furnish heating, cooling, water, electricity,
telephone, or any other utility; b) any consequential damages; regardless of
the cause; or c)) any loss or damages of any kind not resulting from the
LANDLORD's willful nonperformance or grossly negligent performance of its
duties hereunder.

11. INSURANCE                                           

The TENANT shall maintain in full force and effect during the term hereof, a
policy of public liability insurance under which LANDLORD and TENANT are named
insured.  The minimum limits of liability of such insurance shall be
$1,000,000.00 combined single limit for bodily injury and property damage, and
in addition the TENANT shall carry a policy of property insurance for fire and
extended coverage including an all leasehold improvements to the premises on a
replacement cost value.  TENANT agrees to deliver a duplicate copy of said
policy, or a certificate of insurance evidencing such coverage, to LANDLORD.
Such policy shall contain a provision requiring ten (10) days written notice to
the LANDLORD before cancellation of the policy can be effected.

The LANDLORD shall carry and cause to be in full force and effect a fire and
extended coverage insurance policy on the Building an leasehold improvements;
but not on TENANT's personal property, trade fixtures, contents or improvements
owned, or otherwise -in possession of the TENANT, or any improvements to the
premises which improvement and contents are to be insured by the TENANT.  Such
policy shall contain a provision that the policy shall no be canceled except
upon ten (10) days written notice to the TENANT.

Each insurance policy carried by either the LANDLORD of TENANT covering the
Lease Premises or its contents shall provide that the insured party has
relinquished all rights to recover against the other party for loss or damage
resulting from perils insured against by the policy.  LANDLORD and TENANT each
hereby waive any claim based upon liability which may arise



                                       4

<PAGE>   5



against the other so far as the claim relates to loss or damage to the premises
or contents which is covered by insurance or coverable under the aforementioned
insurance policies, whether maintained or not.

12.  MAINTENANCE

The TENANT shall be wholly responsible for the maintenance and repair of the
interior of the Leased Premises, and will keep it in as good condition as when
turned over to tenant, reasonable wear and tear and damage by fire and the
elements excepted.

The TENANT agrees to keep the Leased Premises in a clean, orderly and sanitary
condition and will neither do nor permit to be done therein anything which is.
in violation of insurance polices on the building or that is contrary to law.
The TENANT will neither commit nor suffer waste to the Building or to the
Leased Premises.

The maintenance and repair obligations of the TENANT specifically extend to all
exterior walls, interior doors, interior windows, plumbing and electrical
fixtures within the Lease Premises, except as these obligations may be covered
by manufacturer or contractor warranties.  The LANDLORD agrees to cooperate with
and reasonably assist TENANT in pursuing such warranties which are still in
effect.

The LANDLORD shall at its own expense keep in good order, safe condition and
repair the structural integrity of the Building, except where repairs to the
structural parts are required  due to the fault or negligence of the TENANT, its
employees or invitees, in which case the TENANT shall be responsible.

13.  APPEARANCE AND ACCESS

LANDLORD and TENANT mutually agree to keep the grounds, Building, Leased
Premises and common areas in a condition of good repair and appearance as their
respective responsibilities and rights may allow.  LANDLORD shall provide
general access to TENANT and its invitees to the common areas except as
reasonable security  requirements and temporary conditions may prevent, and
shall make a reasonable effort to keep the common areas well maintained and free
of nuisance.  LANDLORD may establish form time to time and TENANT will abide by
reasonable rules for parking, security, handling of trash and like procedures.

TENANT agrees to keep all of its trash containers, pallets, dumpsters, refuse
and waste within its Leased Premises and not outside or in common areas and
agrees not to litter any of the grounds or entries.  TENANT is responsible for
the cost of the removal of its trash.



                                                     Tenant to Initial
                                           ---------

Window coverings, if desired by TENANT, are to be installed by TENANT at
TENANT's expense and must be horizontal levelour type made of metal.  TENANT
shall also provide and maintain fire extinguishers as required for its
particular use by the City.



                                       5
<PAGE>   6

If TENANT's bathroom is contiguous to a bathroom of an adjoining TENANT, and
LANDLORD installs a common hallway serving these bathrooms , TENANT agrees to
allow the adjoining TENANT the use of its bathroom, and shall have the right to
use the adjoining tenant's bathroom.  TENANT agrees to keep in good order,
cleanliness and repair the contiguous bathroom, as does the adjoining tenant.

TENANT agrees not to have or keep any animals, including dogs and/or cats,
within the Leased Premises.

TENANT agrees to use chair pads under any chairs within the Leased Premises that
is placed at a desk so that wear of the carpet is minimal.

14. LANDLORD'S RESPONSIBILITY

LANDLORD agrees that prior to the commencement of the term hereof, at its sole
cost and expense, it will construct the Building(s), and will also finish the
Leased Premises substantially in accordance with the Building Floor Plan
(Exhibit "A") and Detailed Floor Plan (Exhibit "B") and by specifications in the
Landlord's Finishing Schedule (Exhibit "C") attached and made a part hereof.  It
is understood and agreed that minor changes from any plans or specifications
which may be necessary during construction of the Leased Premises shall not
affect or invalidate this Lease.

TENANT agrees that upon occupancy hereof, it will inspect the Leased Premises in
order to ascertain the condition thereof; that any objections (except for latent
deficiencies not the discoverable ) thereto not delivered in writing to LANDLORD
within 60 days after occupancy shall be deemed waived; and that no
representations, either expressed or implied, have been made regarding the
quality or condition thereof except as specifically stated below:

          (a) The Leased Premises, at the time of initial occupancy, shall
              comply with applicable building codes; and the Americans with
              Disabilities Act.

          (b) The Leased Premises will be completed substantially as agreed to
              in this Lease; and

          (c) The mechanical system serving the Leased Premises will have been
              checked and found to be operating satisfactorily.

 15. CONDEMNATION LOSS

Should all the Leased Premises to be taken in condemnation proceedings or by
exercise of any right of eminent domain, then this Lease shall automatically
terminate as of the date the condemning authority or the authority exercising
its right of eminent domain takes possession of the Leased Premises.  If, as a
result of a partial taking, the Leased Premises is no longer useable for the
purposes specified in of this Lease, then, in any such case, the TENANT or
LANDLORD may terminate this Lease as of the date the condemning authority or the
authority exercising its right of eminent domain takes possession of the
property.  If this Lease is not terminated,  LANDLORD will immediately make all
repairs necessary to make the Leased Promises complete



                                       6



<PAGE>   7




and tenable.  The LANDLORD shall be specifically entitled to all awards for
condemnation, except in the case of awards made specifically foe loss or damage
to TENANT's property or TENANT's relocation expenses.

16. TENANT ASSIGNMENT

The TENANT shall not assign this Lease, and shall not sublet any part of the
Leased Premises without the prior written consent of the LANDLORD.  Said
consent will not be unreasonably withheld or delayed.  Any such assignment or
subletting will not release the TENANT from its responsibilities under this
Lease, unless expressly agreed to in writing by the LANDLORD.  TENANT shall pay
LANDLORD's reasonable attorneys fees for reviewing the sublease.

If the TENANT shall be declared bankrupt, shall have a receiver appointed of
its property, shall make an assignment for the benefit of creditors, or its
rights hereunder shall be taken under execution; it shall be construed as an
assignment of this Lease within the meaning hereof, and the LANDLORD shall have
the right to terminate this Lease.

17. DEFAULT BY TENANT

It is a Default for TENANT: (a) if Base Rent, Additional Rent, or any other sum
due by TENANT under this Lease shall be unpaid of the date payment is required;
(b) if TENANT fails to perform any of the other terms, conditions, covenants and
obligations of this Lease to be observed or performed by the TENANT for more
than (10) days after LANDLORD gives TENANT written notice of such Default ( it
being agreed that a Default, other than failure to pay Base Rent, Additional
Rent or other sums due, which is of such character that the cure thereof
reasonably requires longer than (10) ten days, shall be deemed cured within said
period, if TENANT in good faith commences a cum within the (10) ten day period
and diligently undertakes to complete the cure with reasonable dispatch); (c)
if TENANT abandons the Leased Premises (it being agreed that the Leased Premises
shall be considered abandoned should TENANT fail to openly conduct business from
the aforementioned premises for a period of (7) seven calendar days; (d) if
TENANT or guarantor knowingly misrepresents any material fact in any written
statement provided to the LANDLORD or at its request, pursuant to or in
connection with this Lease; or (e) if TENANT, any guarantor, general partner,
joint venture, or majority shareholder becomes insolvent or the subject of a
bankruptcy petition.

A Default gives LANDLORD the right (without further notice except as
hereinafter expressly provided) to: (a) immediately reenter the Leased
Premises, change the locks, and remove all persons and property; (b) at
TENANT's expense, store or sell said property for TENANT's account; (c) treat
said property as abandoned upon TENANT's failure to remove it within (10) ten
days of written demand to remove; (d) make alterations and repairs; (e) without
terminating the Lease, relet all or part of the Leased Premises, at TENANT's
expense and for its account, on such terms, for such rentals, and for such a
term as LANDLORD in it sole discretion deems advisable' and /or (h) resort to
any other remedy authorized by this Lease or by statute, law or equity.

Whether or not LANDLORD reenters and/or relets the Leased Premises, TENANT will
remain liable, for all periods in which this Lease is in full force and not
terminated, for the Base Rent, Additional Rent and utilities due hereunder,
subject only to a credit for rental received from a substitute tenant over and
above expenses of reletting and other sums due hereunder. Additionally, whether
or not LANDLORD has already resorted to any other above-mentioned



                                       7



<PAGE>   8






right, LANDLORD may elect, by giving a written notice, to terminate the Lease
effective as of any date specified in the notice.  No act, including the
re-entering and/or reletting, except the giving of such notice, shall be deemed
a termination, or acceptance of surrender of the Lease.  Upon said effective
date, TENANT will comply with any surrender provisions.

TENANT will be liable for (a) all expenses and damages incurred by LANDLORD
resulting, whether before or after termination, from a Default, including
without limitation attorney's fees and brokers' fees to obtain a new tenant,
reclaiming possession and alteration or repair costs to obtain a new tenant and
(b) 0% interest on any sum due under the Lease, from the date due.

Whether or not LANDLORD terminates the Lease, LANDLORD may elect, by giving
written notice, to accelerate unaccrued rent and hold TENANT immediately
liable for the amount of the base and additional rents payable during the
remainder of the Lease term.  In addition to this amount due shall be all free
rent received and all above normal construction costs paid by LANDLORD.

18. ALTERATIONS

The TENANT shall not make any alterations to the Lease Premises without the
written consent of the LANDLORD, such consent not to be unreasonably withheld or
delayed.  If the TENANT shall desire to make any such alterations, it shall
furnish plans and specifications of the work to be so performed together with a
construction statement containing a complete breakdown of the cost of all labor
and material included therein, and together with an escrow of cash with Title
Services, Inc. in an amount equal to the estimated cost of all such work, if it
should exceed one thousand dollars ($1,000.00). TENANT agrees to obtain a
building permit from the city for any alterations exceeding fifty dollars
($50.00) in cost.  TENANT agrees that all such work shall be done in a good,
workmanlike manner, and in compliance with applicable building codes and all
applicable laws, including, without limitation, the American Disabilities Act,
that the structural integrity of the Building shall not be impaired, and that no
liens shall attach to the Building or Leased Premises by reason thereof.  No
such alteration(s) shall change the office/finish area to storage/service area
ration without LANDLORD's permission.

The TENANT shall, before the expiration of the Lease, restore the Leased
Premises to its original condition unless the LANDLORD elects that all of part
of the alterations may remain.  Any such alterations shall become the property
of LANDLORD as soon as they are affixed to the Leased Premises and all right,
title and interest therein of the TENANT shall immediately cease unless
otherwise stated in writing.  The TENANT however, shall remain the owner of any
installed trade fixtures and shall have the right to remove such trade fixtures
at the expiration of this Lease Agreement, so long as the Lease Premises and/or
Building is restored to its original conditions.





                                       8
<PAGE>   9

TENANT agrees that, if by reason of TENANT's operations, the use to which TENANT
puts the space, or any alterations made by TENANT (whether or not approved
unconditionally by LANDLORD), applicable law, including, without limitation, the
American Disabilities Act, requires further alterations or modifications of the
lease premises or the building(s), that the TENANT will make such alterations or
modifications so as to promptly address such requirements; or, if TENANT fails
to do so, that TENANT will reimburse LANDLORD promptly for the cost of such
alterations or modifications as LANDLORD may make upon TENANT's default
(LANDLORD having the right but not the obligation to make such alterations or
modifications under that circumstance); and that this provision shall survive
termination or expiration of the lease.

19. SIGNS

The LANDLORD will provide, install, and the TENANT shall maintain in good
repair, one standard exterior entry sign at the TENANT's front entry.  The sign
will remain property of the LANDLORD.  The LANDLORD shall also provide one
standard rear-entry sign to be installed by LANDLORD near the rear door serving
the Leased Premises.  No other signage, including no soliciting or other
directional type signage, promotional material, or identification of any type
shall be place in, on, or externally visible from, any entry, window, outer
door, or exterior surface without the written consent of LANDLORD.  TENANT
agrees that no visitor parking or other parking signage will be installed on any
part of the parking or common areas without the written consent of the LANDLORD.
Exceptions to this are security system signs not to exceed sixty (60) square
inches in size.

20. ENTRY

The TENANT agrees that no additional locks will be placed on any of the
TENANT's doors without the written consent of the LANDLORD.  LANDLORD, its
agents, and its employees shall have the right to enter the premises at all
reasonable times to inspect them, to make repairs, and to maintain the Building
of which the Leases Premises are part.  During the one hundred and eighty (I 80)
days prior to the expiration of the term, the LANDLORD or its agents may exhibit
the Leased Premises to prospective tenant.  LANDLORD shall also have the right
of entry as provided in Paragraph 17.

21. SUBORDINATION

It is mutually agreed that this Lease shall be subordinate to any and all
mortgages, ground leases, or other securities, including any renewals,
modifications, consolidations, replacements and extensions thereof now or
hereafter recorded against the Leased Premises by the LANDLORD.  TENANT's right
to quiet possession of the Leased Premises shall not be disturbed if TENANT is
not in Default and so long as TENANT shall pay the Base and Additional Rents and
observe and perform all of the provisions of this Lease, unless this Lease is
otherwise terminated pursuant to its terms.

22. NOTICES

All notices, consents, demands and requests which may be or are required to be
given by either party of the other, shall be in writing, and sent by United
States registered or certified mail, with return receipt requested, addressed to
the TENANT at the street address set forth in Paragraph I and to the LANDLORD in
care of Marfield, Belgarde and Yaffe Companies, 7841 Wayzata



                                       9



<PAGE>   10



Boulevard, Minneapolis, Minnesota 55426 or to such other address as LANDLORD may
direct in writing in the future.

The date which said registered or certified mail is mailed by the LANDLORD or
TENANT shall be conclusively deemed to be the date on which a notice, consent,
demand, or request is given or made,

The above address of a party may be changed at any time or form time to time by
notice given by said party to the other party in the manner herein above
provided.

23. SHORT FORM LEASE

The parties hereto shall, at the option of either party, execute a short form of
Lease for recording purposes and, in such event, the terms thereof shall
constitute a part of this Lease as fully as though recited at length herein.

24. LANDLORD ASSIGNMENT

The LANDLORD may assign its right, title and interest in this Lease, and such
assignment shall then terminate all the LANDLORD's obligations so long as the
LANDLORD is not in default when such assignment is made and the assignee assumes
the LANDLORD's responsibilities thereafter.

25. OCCUPANCY

If the Leased Premises is not ready for occupancy on the Lease commencement
date, then the lease term shall commence on the date of TENANT's possession but
still terminate on the date previously shown.  LANDLORD shall not be liable to
TENANT for any loss or damage resulting if the Leased Premises is not ready for
occupancy on the commencement date of this Lease.  TENANT agrees to take
possession within ten (10) days after the Leased Premises is substantially ready
for occupancy and permission to occupy is granted by the City.  All TENANT's
obligations hereunder will commence on the first day TENANT occupies any portion
of the Leased Premises.

26.    FIRE REPAIR

In the event of damage to the promises by fire, the elements or other casualty,
LANDLORD shall repair the damage with reasonable dispatch (with Base Rent to
abate in the meantime), unless any mortgagee or financial participant, who from
time to time might have an interest in on the demised promises, shall require
that the fire insurance proceeds to be used to reduce its interest or the
indebtedness on the promises.

If the damage renders the Leased Promises untenantable in part but TENANT
continues to occupy them in part, the Base and Additional Rent shall be reduced
in an equitable manner.

27. QUIET ENJOYMENT

TENANT, upon payment of the Base and Additional Rent herein reserved and upon
performance of all of the terms, covenants and conditions of this Lease by it to
be kept and performed, shall at



                                       10


<PAGE>   11



all times during the term hereof or during any extension or renewal hereof,
peaceably and quietly enjoy the Leased Premises without any disturbance from
LANDLORD or from any other person claiming through LANDLORD.  Upon expiration or
sooner termination of the term hereof, TENANT shall surrender the Leased
Premises in good condition and repair, except for reasonable wear and tear,
condemnation and casualty.

28. HOLDING OVER

If TENANT shall hold over the Leased Premises or any part thereof after the
expiration of the term hereof, or any extension thereof, such holding over
shall be construed only to be a tenancy from day to day subject to all of the
covenants, conditions and obligations hereof except that the Base Rent shall be
150% of the rent normally due.  Nothing herein shall be construed to give
TENANT any rights to holdover and to continue in possession of the Leased
Premises after expiration of the term hereof.

29.    DEPOSIT

TENANT has deposited with LANDLORD the sum of one full month's Base Rent.  Said
sum shall be held by LANDLORD as security for the faithful performance by
TENANT of all the terms, covenants, and conditions of this Lease to be kept and
performed by TENANT.  The deposit shall not bear interest.  If TENANT shall
fully and faithfully perform every provision of this Lease to be performed by
it, the security deposit or any balance thereof shall be returned to TENANT at
the expiration of the Lease term.  Said deposit was made by check # 052767,
dated 8-19-96, $3,461.50, issued by Ringer Corporation.

30. OTHER PROVISIONS

The invalidity or unenforceability of any provisions hereof shall not effect
or impair the validity of any other provision.  The headings herein are
inserted only for convenience and reference and shall have no substantive 
import. Where necessary, the singular imports the plural and vice
versa, and masculine, feminine and neuter pronouns and expressions are
interchangeable. The Lease shall bind and inure to the benefit of the LANDLORD
and TENANT, their respective heirs, administrators, legal representatives,
successors and assigns.

During the term of the Lease, LANDLORD's acceptance of an amount which is less
then the amount due at that time, will be deemed partial payment only, not
payment in full.

This Lease shall be governed by Minnesota Law.

One or more waivers of any provision by either party shall not be construed as a
waiver of subsequent breach of same.  Failure to enforce or delay in enforcing
any right hereunder will not be construed as a waiver thereof.  Each party
expressly (a) consents to the maintaining of any such action in any court of
competent subject matter jurisdiction, and (b) agrees that the mailing, with
postage pre-paid, registered or certified mail, of any complaint or other legal
process to it, at either the address stated in this Lease for notices or any
other address where that party is then actually residing or doing business,
constitutes legally sufficient service of the same upon that party as of the
postmark date of the mailing, it being each party's intent to waive in the event
of such a mailing, any insufficiency of service of process, lack of personal
jurisdiction claim, or the like that might otherwise arise from provisions of
the law otherwise requiring a different form of personal service.


                                       11
<PAGE>   12





TENANT and any guarantors agree to provide LANDLORD with a current financial
statement on or before (4) months after the end of their fiscal year.  The
financial statement shall meet generally accepted accounting principles.

TENANT hereby agrees that in the event of a purchase of the Leased Premises by
another party, TENANT will sign a Lease Estoppel Agreement, stating that this
Lease agreement between TENANT and LANDLORD is in full force and effect and that
all covenants herein have been met.  Any uncompleted covenants should be noted
and listed on the Lease Estoppel Agreement.

SECTION 31: BROKERAGE: It is hereby agreed and understood that the Tenant is
represented by Landmark Partners, as their agent. It is further agreed that the
Landlord will pay all and any fees/commissions due for this transaction to
Landmark Partners within thirty days of Tenant occupancy, It is further agreed
that both Tenant and Landlord will indemnify each other against all and any
claims arising from any and all sources other than Landmark Partners in regards
to fees or commissions that may result from this transaction.

     EXHIBITS AND ADDENDUMS

     This instrument contains all of the agreements made between the parties and
     may not be modified orally or in any manner other than by agreement in
     writing signed by all parties to this Lease.  The following exhibits and
     addendums are attached and hereby made a part of this Lease:

<TABLE>
<S>                        <C>
          X   Exhibit "A"     Building Floor Plan                              
         ---
          X   Exhibit "B"     Detailed Floor Plan or Blueprint                 
         ---
          X   Exhibit "C"     Landlord's Finishing Schedule                    
         ---
          X   Exhibit "D"     TENANT's and/or Guarantor(s)                     
         ---                  Financial Statement Rider                        
                              
          X   Exhibit "E"     Material Use Rider  
         ---

              Exhibit "F"     Personal Guaranty
         ---
</TABLE>

The signatories below warrant that they are duly authorized to enter into this
Lease representing the parties hereto.

IN WITNESS WHEREOF, the parties hereto have caused this Lease to be executed the
day and year first above written.

                                       
LANDLORD                                    TENANT
By                                          By   Ringer Corporation
   --------------------------------            --------------------------
   Partner
-----------------------------------         -----------------------------

Its Authorized Agent                        Its Chief Financial Officer
                                                -------------------------