-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 JVu7YNUL2aR5cu4oIR5rYUITdey1CdytHz1EhkG1OseihqaTaPcXgE+aEoytuaOa
 tYebGtOK3i1VoiGl+GMjgQ==

<SEC-DOCUMENT>0001029296-03-000004.txt : 20030717
<SEC-HEADER>0001029296-03-000004.hdr.sgml : 20030717
<ACCEPTANCE-DATETIME>20030717162132
ACCESSION NUMBER:		0001029296-03-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030602
FILED AS OF DATE:		20030717

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BISCO INDUSTRIES INC
		CENTRAL INDEX KEY:			0001029296
		STATE OF INCORPORATION:			IL

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-10394
		FILM NUMBER:		03791453

	BUSINESS ADDRESS:	
		STREET 1:		1500 N. LAKEVIEW AVE.
		CITY:			ANAHEIM
		STATE:			CA
		ZIP:			92807
		BUSINESS PHONE:		7146932901

	MAIL ADDRESS:	
		STREET 1:		1500 N. LAKEVIEW AVE.
		CITY:			ANAHEIM
		STATE:			CA
		ZIP:			92807

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			DATA I/O CORP
		CENTRAL INDEX KEY:			0000351998
		STANDARD INDUSTRIAL CLASSIFICATION:	INSTRUMENTS FOR MEAS & TESTING OF ELECTRICITY & ELEC SIGNALS [3825]
		IRS NUMBER:				910864123
		STATE OF INCORPORATION:			WA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		10525 WILLOWS RD NE
		STREET 2:		P O BOX 97046
		CITY:			REDMOND
		STATE:			WA
		ZIP:			98073-9746
		BUSINESS PHONE:		4258676922

	MAIL ADDRESS:	
		STREET 1:		P O BOX 97046
		STREET 2:		10525 WILLOWS RD NE
		CITY:			REDMOND
		STATE:			WA
		ZIP:			98073-9746
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-06-02</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000351998</issuerCik>
        <issuerName>DATA I/O CORP</issuerName>
        <issuerTradingSymbol>DAIO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001029296</rptOwnerCik>
            <rptOwnerName>BISCO INDUSTRIES INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Data I/O</value>
        </securityTitle>
        <transactionDate>
            <value>2003-06-02</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>S</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>2000</value>
            </transactionShares>
            <transactionValue>
                <value>2.02</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>452025</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>Profit Sharing Plan</value>
            </natureOfOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Data I/O</value>
        </securityTitle>
        <transactionDate>
            <value>2003-06-03</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>S</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>17500</value>
            </transactionShares>
            <transactionValue>
                <value>2.02</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>970201</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>Bisco Industries</value>
            </natureOfOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>


    <ownerSignature>
        <signatureName>Glen Ceiley</signatureName>
        <signatureDate>2003-07-17</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----