Exhibit 4.12

                 Permanent Global Registered Fixed Rate Security


                  THESE NOTES ARE A GLOBAL SECURITY WITHIN THE MEANING OF THE
INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY
OR A NOMINEE THEREOF. UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR
NOTES IN CERTIFICATED FORM, THESE NOTES MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE
BY THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO A NOMINEE OF
DTC OR BY DTC OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH
SUCCESSOR DEPOSITARY. UNLESS THESE NOTES ARE PRESENTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC TO AT&T CORP. OR ITS AGENT FOR REGISTRATION OF TRANSFER,
EXCHANGE OR PAYMENT, AND ANY NOTE ISSUED IS REGISTERED IN THE NAME OF CEDE &
CO., OR IN SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC
(AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED
BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE
HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE
REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.


                                   AT&T CORP.

                  $400,000,000 6.75% Notes due 2004 (Series 2)

REGISTERED                                                 CUSIP NO. 001957 BF 5
No. ______

                  AT&T Corp., a New York corporation (herein referred to as the
"Company"), for value received, hereby promises to pay to CEDE & CO. or
registered assigns the principal sum of FOUR HUNDRED MILLION DOLLARS on April 1,
2004 (the "Maturity Date"), and to pay interest semiannually on April 1 and
October 1 (each, an "Interest Payment Date"), commencing April 1, 2003, on said
principal sum at the rate per annum specified in these Notes, from ________,
2002 (the "Original Issue Date") until the principal thereof is paid or made
available for payment.

                  Reference is hereby made to the further provisions of this
global security (the "Global Security") set forth on the reverse hereof, which
further provisions shall for all purposes have the same effect as if set forth
in this place.

                  This Global Security shall not be valid or become obligatory
for any purpose until the certificate of authentication hereon shall have been
executed by the Trustee under the Indenture referred to herein.

                  IN WITNESS WHEREOF, the Company has caused this Global
Security to be duly executed under its corporate seal.

Dated:  _________, 2002


                                                          
TRUSTEE'S CERTIFICATE OF AUTHENTICATION                      AT&T CORP.

This is one of the Securities described in the               By:______________________________
within-mentioned Indenture.                                      Vice President and Treasurer

THE BANK OF NEW YORK,                                        ATTEST:
                           As Trustee

By:__________________________________________                _________________________________
         Authorized Signatory                                    Assistant Secretary




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                                REVERSE OF NOTES

                  Payment of the principal of, and interest on, this Global
Security will be made in immediately available funds at the office or agency of
the Trustee maintained for that purpose in the Borough of Manhattan, The City of
New York, State of New York, in such coin or currency of the United States of
America as at the time of payment shall be legal tender for payment of public
and private debts; provided, however, that at the option of the Company payment
of interest on any Notes other than interest due at the Maturity Date shown
above may be made by check mailed to the address of the person entitled thereto
as such address shall appear in the Note register. Interest will be paid to
persons in whose names the Notes are registered at the close of business on the
March 15 or September 15, as the case may be, prior to any Interest Payment
Date.

                  These Notes are one of a duly authorized issue of securities
of the Company, issued and to be issued under and pursuant to an indenture dated
as of September 7, 1990 as amended by the First Supplemental Indenture dated as
of October 30, 1992 and the Second Supplemental Indenture dated as of _________,
2002 (herein referred to as the "Indenture"), duly executed and delivered by the
Company to The Bank of New York, as trustee (herein referred to as the
"Trustee"), to which Indenture and all indentures supplemental thereto reference
is hereby made for description of the rights, limitations of rights,
obligations, duties and immunities thereunder of the Trustee, the Company and
the Holder (the words "Holders" or "Holder" meaning the registered holders or
registered holder) of these Notes.

                  In case an Event of Default with respect to the Notes, as
defined in the Indenture, shall have occurred and be continuing, the principal
hereof may be declared, and upon such

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declaration shall become due and payable in the manner, with the effect and
subject to the conditions provided in the Indenture.

                  The Indenture permits, with certain exceptions as therein
provided, the amendment thereof and the modification of the rights and
obligations of the Company and the rights of the Holders of the Notes to be
affected under the Indenture at any time by the Company and the Trustee with the
consent of the Holders of a majority in principal amount of the outstanding
Notes. The Indenture also contains provisions permitting the Holders of not less
than a majority in principal amount of the outstanding Notes, on behalf of the
Holders of all Notes, to waive compliance by the Company with certain provisions
of the Indenture. The Indenture also provides that the Holders of not less than
a majority in principal amount of the outstanding notes may waive certain past
defaults and their consequences on behalf of the Holders of all Notes. Any such
consent or waiver by the Holder of any Note shall be conclusive and binding upon
such Holder and upon all future Holders of such Note and of any Note issued upon
registration of transfer hereof or in exchange herefor or in lieu hereof whether
or not notation of such consent or waiver is made upon these Notes.

                  The Indenture also provides that the Covered Transactions (as
defined in the Indenture), individually or together, (a) will not result in a
consolidation, merger, sale, conveyance or other transfer of property of the
Company (including stock of subsidiaries) as an entirety or substantially as an
entirety for purposes of Section 5.01 of the Indenture or any other provision of
the Indenture or these Notes, and (b) will not violate Sections 5.01, 5.02, or
5.03 of the Indenture or any other provision of the Indenture or these Notes,
regardless of whether any person assumes any of the indebtedness outstanding
under the Indenture or any other obligation under the Indenture or these Notes.


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                  The Indenture contains provisions setting forth certain
conditions to the institution of proceedings by Holders of Securities with
respect to the Indenture or for any remedy under the Indenture.

                  No reference herein to the Indenture and no provision of these
Notes or of the Indenture shall alter or impair the obligation of the Company,
which is absolute and unconditional, to pay the principal of and interest on
these Notes at the place, at the respective times, at the rate and in the coin
or currency herein prescribed.

                  The Notes are issuable as registered Notes without coupons in
denominations of U.S. $1,000 or any amount in excess thereof which is a multiple
of U.S.$1,000 at the office or agency of the Company referred to above and in
the manner and subject to the limitations provided in the Indenture. Notes may
be exchanged without service charge for like aggregate principal amount of Notes
having the same maturity, interest rate, redemption provisions, repayment
provisions, and Original Issue Date of other authorized denominations.


                  The initial interest rate per annum on the principal sum of
these Notes is 6.75%. At the Effective Time (as defined in the Merger
Agreement), the interest rate per annum on the principal sum of these Notes will
be increased to ____%. If the Merger Agreement is terminated and the Mergers (as
defined therein) are abandoned at any time prior to the Effective Time, the
interest rate per annum on the principal sum of these Notes shall remain at
6.75%. These Notes have been exchanged for 6.75% Notes Due 2004 (the "Prior
Notes"). Interest accrued and unpaid on the Prior Notes through but not
including the date of such exchange will be paid, without interest, on the first
Interest Payment Date hereunder.



                                      -5-

                  "MERGER AGREEMENT" means the Agreement and Plan of Merger by
and among the Company, AT&T Broadband Corp., Comcast Corporation, AT&T Broadband
Acquisition Corp., Comcast Acquisition Corp. and AT&T Comcast Corporation, dated
as of December 19, 2001, as it may be amended, supplemented or otherwise
modified from time to time, whether prior to or after the date hereof.

                  These Notes may not be redeemed and are not subject to
repayment at the option of the Holder.

                  Upon due presentment for registration of transfer of these
Notes at the above-mentioned office or agency of the Trustee, a new Global
Security or Notes of authorized denominations, for a like aggregate principal
amount will be issued to the transferee as provided in the Indenture. No service
charge shall be made for any such transfer, but the Company may require payment
of a sum sufficient to cover any tax or other governmental charge that may be
imposed in relation thereto.

                  The Company, the Trustee, and any agent of the Company and the
Trustee may deem and treat the Holder hereof as the absolute owner hereof
(whether or not this Global Security shall be overdue and notwithstanding any
notation of ownership or other writing hereon) for the purpose of receiving
payment of or on account of the principal hereof and subject to the provisions
above, of premium or interest thereon, and for all other purposes and neither
the Company nor the Trustee nor any such agent shall be affected by any notice
to the contrary.

                  No recourse shall be had for the payment of the principal of,
or the interest on, this Global Security or for any claims based hereon, or
otherwise in respect hereof, or based on or with respect of the Indenture or any
indenture supplemental therein against any incorporator,

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shareholder, officer or director as such, past, present or future, of the
Company or of any successor corporation, either directly or through the Company
or of any successor corporation whether by virtue of any constitution, statute
or rule of law or by the enforcement of any assessment or penalty or otherwise,
all such liability being, by the acceptance hereof and as part of the
consideration for the issue hereof, expressly waived and released.

                  This Global Security shall be deemed to be a contract made
under the laws of the State of New York and for all purposes shall be governed
by and construed in accordance with the laws of said State.

                  All terms used in this Global Security which are defined in
the Indenture shall have the meanings assigned to them in the Indenture.


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                                  ABBREVIATIONS

                  The following abbreviations, when used in the inscription on
the face of this instrument, shall be construed as though they were written out
in full according to applicable laws or regulations:

TEN COM              -   as tenants in common
TEN ENT              -   as tenants by the entireties
JT TEN               -   as joint tenants with right of survivorship and not as
                         tenants in common
UNIF GIFT MIN ACT    -   ________________(Cust)__________________________(Minor)
Under Uniform Gifts to Minor Act ________________________________________(State)



                  Additional abbreviations may also be used though not in the
above list.

                  FOR VALUE RECEIVED, the undersigned hereby sell(s), assign(s)
and transfer(s) unto

[PLEASE INSERT SOCIAL SECURITY OR
OTHER IDENTIFYING NUMBER OF ASSIGNEE]

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[PLEASE PRINT OR TYPE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE]

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the within Notes and all rights thereunder, hereby irrevocably constituting and
appointing such person attorney to transfer such Note on the books of the
Company, with full power of substitution in the premises.

Dated:___________________________________

NOTICE:  The signature to this assignment must correspond with the name as
         written upon the face of the within Notes in every particular without
         alteration or enlargement or any change whatsoever.

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