SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549
                            -------------------------

                                  SCHEDULE 13G
                                 (Rule 13d-102)

                    INFORMATION TO BE INCLUDED IN STATEMENTS
                  FILED PURSUANT TO RULES 13d-1(b), (c) AND (d)
                AND AMENDMENTS THERETO FILED PURSUANT TO 13d-2(b)
                         (Amendment No. ____________)1

                                    Castelle

                                (Name of Issuer)

                                     Common
                         (Title of Class of Securities)

                                   147905-10-3
                                 (CUSIP NUMBER)

                                 April 29, 2004

             (Date of Event Which Requires Filing of this Statement)


Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

                             / /    Rule 13d-1(b)
                             /X/    Rule 13d-1(c)
                             / /    Rule 13d-1(d)





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1    The  remainder  of this  cover  page  shall be filled  out for a  reporting
     person's  initial  filing on this form with respect to the subject class of
     securities,  and for any subsequent amendment containing  information which
     would alter disclosures provided in a prior cover page.

     The  information  required on the remainder of this cover page shall not be
     deemed to be  "filed"  for the  purpose  of  Section  18 of the  Securities
     Exchange  Act of 1934  or  otherwise  subject  to the  liabilities  of that
     section of the Act but shall be subject to all other  provisions of the Act
     (however, see the Notes).





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        NAME OF REPORTING PERSONS:         Daniel Zeff
1.      I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
--------------------------------------------------------------------------------
        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
2.
                                                                   (a)     0
                                                                   (b)
--------------------------------------------------------------------------------
        SEC USE ONLY
3.
--------------------------------------------------------------------------------
        CITIZENSHIP OR PLACE OF ORGANIZATION        United States of America
4.
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     NUMBER OF      5.       SOLE VOTING POWER                       368,123
      SHARES
   BENEFICIALLY
     OWNED BY
      EACH
    REPORTING
   PERSON WITH
--------------------------------------------------------------------------------
                          SHARED VOTING POWER                              0
                    6.
--------------------------------------------------------------------------------
                          SOLE DISPOSITIVE POWER                     368,123
                    7.
--------------------------------------------------------------------------------
                          SHARED DISPOSITIVE POWER                         0
                    8.
--------------------------------------------------------------------------------
        AGGREGATE AMOUNT BENEFICIALLY OWNED BY
        EACH REPORTING PERSON                                        368,123
9.

--------------------------------------------------------------------------------
        CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES
10.     CERTAIN SHARES*
--------------------------------------------------------------------------------
        PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)              10.39%
11.
--------------------------------------------------------------------------------
        TYPE OF REPORTING PERSON*                                         IN
12.
--------------------------------------------------------------------------------

                      *SEE INSTRUCTION BEFORE FILLING OUT!


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Item 1(a).        Name of Issuer:

                           Castelle

Item 1(b).        Address of Issuer's Principal Executive Offices:

                           855 Jarivs Drive
                           Morgan Hill, CA 95037

Item 2(a).        Name of Person Filing:

                           Daniel Zeff
                           (the "Reporting Person")

Item 2(b).        Address of Principal Business Office or, if None, Residence:

                           The principal business address of the Reporting
Person is:

                           c/o Zeff Holding Company, LLC
                           50 California Street, Suite 1500
                           San Francisco, CA 94111


Item 2(c).        Citizenship:

                           Mr. Zeff is a United States citizen.

Item 2(d).        Title of Class of Securities:

                           Common Stock, par value $.01

Item 2(e).        CUSIP Number:

                           147905-10-3



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Item 3.    If this statement is filed pursuant to Rule 13d-1(b), or 13d-2(b) or
           (c), check whether the person filing is a:       Not Applicable

                      (a)           [ ] Broker or dealer registered under
                                    Section 15 of the Exchange Act;

                      (b)           [ ] Bank as defined in Section 3(a)(6) of
                                    the Exchange Act;

                      (c)           [ ] Insurance Company as defined in Section
                                    3(a)(19) of the Exchange Act;

                      (d)           [ ] Investment Company registered under
                                    Section 8 of the Investment Company Exchange
                                    Act;

                      (e)           [ ] Investment Adviser in accordance with
                                    Rule 13d-1(b)(1)(ii)(E);

                      (f)           [ ] Employee Benefit Plan or Endowment Fund
                                    in accordance with Rule 13d-1(b)(1)(ii)(F);

                      (g)           [ ] Parent Holding Company or Control Person
                                    in accordance with Rule 13d-1(b)(1)(ii)(G);

                      (h)           [ ] Saving Association as defined in Section
                                    3(b) of The Federal Deposit Insurance Act;

                      (i)           [ ] Church Plan that is excluded from the
                                    definition of an Investment Company under
                                    Section 3(c)(14) of the Investment Company
                                    Act;

                      (j)           [ ] Group, in accordance with Rule
                                    13d-1(b)(1)(ii)(J).




                                                                                           

Item 4.           Ownership.

                  A.  Daniel Zeff

                  (a)  Amount beneficially owned:                                             368,123
                  (b)  Percent of Class:                                                        10.39%
                  (c)   Number of shares as to which such person has:

                      (i)  Sole power to vote or direct the vote:                             368,123
                      (ii) Shared power to vote or to direct the vote:                              0
                      (iii)Sole power to dispose or direct the disposition of:                368,123
                      (iv) Shared power to dispose or to direct the disposition of:                 0





                           As calculated in accordance with Rule 13d-3 of the
                           Securities Exchange Act of 1934, as amended, Daniel
                           Zeff beneficially owns 368,123 shares of the Issuer's
                           Common Stock, par value $.01 ("Common Stock"),

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                           representing 10.39% of the Common Stock. Mr. Zeff
                           does not directly own any shares of Common Stock, but
                           he indirectly owns 368,123 shares of Common Stock in
                           his capacity as the sole manager and member of Zeff
                           Holding Company, LLC a Delaware limited liability
                           company ("ZHC") which in turn serves as the general
                           partner for Zeff Capital Partners I, L.P. ("ZCP"), a
                           Delaware Limited Partnership. Mr. Zeff also provides
                           discretionary investment management services to Zeff
                           Capital Offshore Fund ("ZCF"), a class of shares of
                           Spectrum Galaxy Fund Ltd., a company incorporated in
                           the British Virgin Islands.

Item 5.           Ownership of Five Percent or Less of a Class.

                           If this statement is being filed to report the fact
                           that as of the date hereof the reporting person has
                           ceased to be the beneficial owner of more than five
                           percent of the class of securities, check the
                           following: [ ]

Item 6.           Ownership of More than Five Percent on Behalf of Another
                  Person.

                           Each of ZCP and ZCF have the right to receive and the
                           power to direct the receipt of dividends from, and
                           the proceeds from the sale of, the shares of Common
                           Stock held by them.

Item 7.           Identification and Classification of the Subsidiary Which
                  Acquired the Security Being Reported on by the Parent
                  Holding Company.

                           Not Applicable

Item 8.           Identification and Classification of Members of the Group.

                           Not Applicable

Item 9.           Notice of Dissolution of Group.

                           Not Applicable


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Item 10. Certification.

     By signing  below I certify  that,  to the best of my knowledge and belief,
the  securities  referred  to above were not  acquired  and are not held for the
purpose of or with the effect of  changing  or  influencing  the  control of the
issuer of the  securities  and were not acquired and are not held in  connection
with or as a participant in any transaction having that purpose or effect.

                                    SIGNATURE


     After  reasonable  inquiry and to the best of my  knowledge  and belief,  I
certify that the information  set forth in this statement is true,  complete and
correct.

Dated:  April 30, 2004

                                                          /s/ Daniel Zeff
                                                          ---------------
                                                              Daniel Zeff





     Attention:  Intentional  misstatements  or  omissions  of  fact  constitute
Federal criminal violations (see 18 U.S.C. 1001).



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