As filed with the Securities and Exchange Commission on April 25, 2005 
SEC File No. 333-121566
================================================================================

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                               AMENDMENT NO. 1 TO
                                    FORM S-3
                             REGISTRATION STATEMENT
                        UNDER THE SECURITIES ACT OF 1933
                              DATA I/O CORPORATION
             (Exact Name of Registrant as Specified in its Charter)

         Washington                                            91-0864123
(State or other jurisdiction of                            (I.R.S. Employer
incorporation or organization)                             Identification No.)

                             10525 Willows Road N.E.
                            Redmond, Washington 98052
                                 (425) 881-6444
  (Address, including zip code, and telephone number, including area code, of
                   registrant's principal executive offices)

                                 Joel S. Hatlen
        Vice President, Chief Financial Officer, Secretary and Treasurer
                             10525 Willows Road N.E.
                            Redmond, Washington 98052
                                 (425) 881-6444
 (Name, address, including zip code, and telephone number, including area code,
 of agent for service)

                                    Copy to:
                           Kimberley R. Anderson, Esq.
                              Dorsey & Whitney LLP
                          1420 Fifth Avenue, Suite 3400
                             Seattle, WA 98101-4010
                            Telephone: (206) 903-8800
                            Facsimile: (206) 903-8820

        Approximate date of commencement of proposed sale to the public:
   From time to time after the effective date of this Registration Statement.

     If the only  securities  being  registered  on this Form are to be  offered
pursuant to dividend or interest  reinvestment plans, please check the following
box. |_|

     If any of the securities being registered on this Form are to be offered on
a delayed or continuous  basis  pursuant to Rule 415 under the Securities Act of
1933, as amended, other than securities offered only in connection with dividend
or interest reinvestment plans, check the following box. |X|

     If this Form is filed to  register  additional  securities  for an offering
pursuant to Rule 462(b) under the  Securities  Act of 1933,  as amended,  please
check the  following  box and list the  Securities  Act  registration  statement
number of the earlier  effective  registration  statement for the same offering.
|_|

     If this Form is a  post-effective  amendment  filed pursuant to Rule 462(c)
under the Securities  Act of 1933, as amended,  check the following box and list
the  Securities  Act  registration  statement  number of the  earlier  effective
registration statement for the same offering. |_|

     If delivery of the  prospectus is expected to be made pursuant to Rule 434,
check the following box. |_|
                           
                          ---------------------------

     The registrant  hereby amends this  Registration  Statement on such date or
dates as may be necessary to delay its effective date until the registrant shall
file a further  amendment  which  specifically  states  that  this  Registration
Statement shall  thereafter  become effective in accordance with Section 8(a) of
the  Securities  Act of 1933, as amended,  or until the  registration  statement
shall become  effective on such date as the Securities and Exchange  Commission,
acting pursuant to said Section 8(a), may determine.

================================================================================



The  information  in this  prospectus  is not complete  and may be changed.  The
selling  shareholders  may not sell  these  securities  until  the  registration
statement filed with the Securities and Exchange  Commission is effective.  This
prospectus is not an offer to sell these securities, and it is not soliciting an
offer to buy  these  securities  in any  state  where  the  offer or sale is not
permitted.

                   Subject to completion: Dated April 25, 2005

                              DATA I/O CORPORATION

                        1,050,000 Shares of Common Stock

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

This prospectus relates to the sale, transfer or distribution of up to 1,050,000
shares of the common stock, without par value per share, of Data I/O Corporation
by the selling  shareholders  described  herein.  The price at which the selling
shareholders  may sell the shares will be  determined by the  prevailing  market
price for the shares or in negotiated transactions.

We will not receive any  proceeds  from the sale or  distribution  of the common
stock by the  selling  shareholders.  We could  receive up to  $339,625 in gross
proceeds from the cash exercise of certain options by the selling  shareholders,
which proceeds would be used for general corporate purposes.

Our  common  stock is quoted on the Nasdaq  SmallCap  Market  under the  trading
symbol  "DAIO."  On April 22,  2005,  the last price for our  common  stock,  as
reported by the Nasdaq SmallCap Market, was $2.80 per share.

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

See "Risk  Factors"  beginning  at page two to read about  certain  factors  you
should consider before buying shares of our common stock.

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

Neither  the  Securities  and  Exchange  Commission  nor  any  state  securities
commission  has approved or disapproved  of these  securities,  or determined if
this prospectus is truthful or complete. Any representation to the contrary is a
criminal offense.

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

                     The date of this prospectus is       , 2005.



                                       i

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                                TABLE OF CONTENTS

Section                                                                 Page

Data I/O Corporation......................................................4
Risk Factors..............................................................5
Special Note About Forward-Looking Information...........................10
Use of Proceeds..........................................................10
Selling Shareholders.....................................................10
Plan of Distribution.....................................................11
Validity of Common Stock.................................................11
Experts..................................................................11
Where You Can Find More Information......................................12


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================================================================================



                              DATA I/O CORPORATION

Data I/O Corporation ("Data I/O") designs,  manufactures,  and sells programming
systems  used  by  designers  and  manufacturers  of  electronic  products.  Our
programming  system products are used to program  integrated  circuits ("ICs" or
"devices" or  "semiconductors")  so that the ICs will function as desired in the
customer's  electronic  product.  They are an important tool for the electronics
industry  experiencing  growing use of  programmable  ICs.  Data I/O markets and
distributes our programming  systems  worldwide,  and is a global leader in this
market. Data I/O was incorporated in the state of Washington in 1969.

Data I/O  Mission.  Data  I/O's  mission  is to design  and  deliver  innovative
customer-focused  programming solutions,  which enable customers to manage their
firmware supply chain,  getting their products to market faster,  while reducing
costs in their process.  We align our products and services to make  programming
easy, delight our customers and satisfy their whole product needs.

Helping customers manage their firmware supply chain. Much of the innovation and
competitive  advantage of today's  electronic  products  comes from the software
buried  inside  the  product,  which  is  commonly  referred  to as  "firmware."
Companies use firmware to differentiate  their products from their  competitors'
products, constantly writing new code to add features. This allows them to build
multiple  models with identical  hardware and many versions of firmware,  all on
one  production  line.  Any  improvement  in  production  efficiency  boosts the
profitability   of  all  products  on  that  line.   Many   original   equipment
manufacturers  ("OEMs") now outsource  production to  specialists  in electronic
manufacturing  services  ("EMS") to  maximize  the  profit  impact  from  highly
efficient  production.  The  challenges  of managing the  firmware  supply chain
remain,  however,  and can even increase  with this  additional  interface.  Our
systems  allow our  customers - both OEM and EMS  companies - to build  products
with the exact firmware  features that consumers  specify,  virtually  real-time
with the latest  software  release.  We help our customers  eliminate  inventory
risks,  delays,  rework,  and lost market  opportunities  while enabling them to
better serve their customers.

Connected  Strategy.  Data I/O's connected  strategy  leverages  network capable
products to move the customer's intellectual property seamlessly and securely up
and down the supply chain.  Our connected  strategy allows  customers to connect
engineering to manufacturing to end customers.

Our principal  executive  offices are located at 10525 Willows Road NE, Redmond,
Washington  98052.  Our  telephone  number at that  location is (425)  881-6444.
Unless the context otherwise  requires,  when used herein, the terms "we," "us,"
"our,"  "Data  I/O," or the  "Company"  refers to Data I/O  Corporation  and its
subsidiaries.



                                  RISK FACTORS

Our business is subject to a number of risks, some of which are discussed below.
Other risks are presented  elsewhere in this  prospectus and in the  information
incorporated by reference into this prospectus. Before deciding to invest in our
company or to  maintain  or  increase  your  investment,  you  should  carefully
consider  the risks  described  below,  in  addition  to the  other  information
contained in this prospectus, our Annual Report on Form 10-K for the fiscal year
ended  December  31,  2004 and in our  other  filings  with the  Securities  and
Exchange Commission (the "SEC"), including any subsequent reports filed on Forms
10-K, 10-Q and 8-K. The risks and uncertainties described below are not the only
ones that we face.  Additional risks and uncertainties not presently known to us
or that we currently deem immaterial may also affect our business and results of
operations.  If any of these risks  actually  occurs,  our  business,  financial
condition or results of operations could be seriously harmed. In that event, the
market price for our common stock could  decline and you may lose all or part of
your investment.

DELAYS IN DEVELOPMENT, INTRODUCTION AND SHIPMENT OF NEW PRODUCTS MAY RESULT IN A
DECLINE IN SALES.

Data I/O  currently is developing  new  engineering  and  automated  programming
systems.  Significant technological,  supplier,  manufacturing or other problems
may delay the development, introduction or production of these products.

For example, we may encounter these problems:

o technical problems in the development of a new programming system platform or
  the robotics for new automated handing systems

o inability to hire qualified personnel

o delays or failures to perform by third parties involved in our development
  projects

Delays in the development,  completion and shipment of new products,  or failure
of customers to accept new products, may result in a decline in sales.

QUARTERLY  FLUCTUATIONS IN OUR OPERATING  RESULTS MAY ADVERSELY AFFECT OUR STOCK
PRICE.

Data I/O's operating  results tend to vary from quarter to quarter.  Our revenue
in each quarter  substantially depends upon orders received within that quarter.
Conversely,  our  expenditures  are based on  investment  plans and estimates of
future revenues. We may, therefore,  be unable to quickly reduce our spending if
our revenues decline in a given quarter. As a result, operating results for that
quarter  will  suffer.  Our  results of  operations  for any one quarter are not
necessarily indicative of results for any future periods.

Other  factors,  which may cause our quarterly  operating  results to fluctuate,
include:

o increased competition

o timing of new product announcements

o product releases and pricing changes by us or our competitors

o market acceptance or delays in the introduction of new products

o production constraints

o labor or material shortages

o the timing of significant orders

o the sales channel mix of direct vs. indirect distribution

o war or terrorism

o health issues (such as SARS)

o customers' budgets

o adverse movements in exchange rates, interest rates or tax rates

o cyclical nature of demand for our customers' products

o general economic conditions in the countries where we sell products

Due  to all of the  foregoing  factors,  it is  possible  that  in  some  future
quarters,  our  operating  results  will be below  expectations  of analysts and
investors.

FAILURE TO ADAPT TO TECHNOLOGY  TRENDS IN OUR INDUSTRY MAY NEGATIVELY IMPACT OUR
COMPETITIVENESS AND FINANCIAL RESULTS.

Product technology in Data I/O's industry evolves rapidly, making timely product
innovation  essential to success in the marketplace.  Introducing  products with
improved  technologies or features may render our existing products obsolete and
unmarketable.  Technological  advances that may  negatively  impact our business
include:

o new device package types, densities, and technologies requiring
  hardware and software changes in order to be programmed by our products

o electronics equipment manufacturing practices, such as widespread use of
  custom in-circuit programming

o customer software platform preferences different from those on which our
  products operate

o more rigid industry standards, which would decrease the value-added element
  of our products and support services

If we cannot  develop  products  in a timely  manner  in  response  to  industry
changes,  or if our products do not perform  well,  our  business and  financial
condition will be adversely affected. Also, our new products may contain defects
or errors  that give rise to product  liability  claims  against us or cause our
products to fail to gain market  acceptance.  Our future success  depends on our
ability to successfully  compete with other  technology  firms in attracting and
retaining key technical personnel.

A DECLINE IN ECONOMIC  AND MARKET  CONDITIONS  MAY RESULT IN  DECREASED  CAPITAL
SPENDING BY OUR CUSTOMERS.

Our business is highly  impacted by capital  spending  plans and other  economic
cycles that affect the users and  manufacturers  of ICs.  These  industries  are
highly  cyclical and are  characterized  by rapid  technological  change,  short
product  life cycles,  fluctuations  in  manufacturing  capacity and pricing and
gross margin  pressures.  Our operations  may in the future reflect  substantial
fluctuations from  period-to-period as a consequence of these industry patterns,
general economic conditions affecting the timing of orders from major customers,
and other  factors  affecting  capital  spending.  These  factors  could  have a
material adverse effect on our business and financial condition.

WE HAVE A  HISTORY  OF RECENT  OPERATING  LOSSES  AND MAY BE UNABLE TO  GENERATE
ENOUGH REVENUE TO ACHIEVE AND MAINTAIN PROFITABILITY.

We have  incurred  net losses in two of our last  three  fiscal  years.  We will
continue  to examine our level of  operating  expense  based upon our  projected
revenues.  Any planned  increases  in  operating  expenses  may result in larger
losses in future periods if projected revenues are not achieved. As a result, we
may need to  generate  greater  revenues  than we have  recently  to achieve and
maintain  profitability.  However, we cannot provide assurance that our revenues
will increase and our strategy may not be successful resulting in future losses.

OUR RECENT  RESTRUCTURING  ACTIVITIES  MAY HAVE A NEGATIVE  IMPACT ON OUR FUTURE
OPERATIONS.

Our restructuring plans may yield unanticipated consequences,  such as increased
burden on our administrative, operational, and financial resources and increased
responsibilities  for our  management  personnel.  As a result,  our  ability to
respond to  unexpected  challenges  may be impaired and we may be unable to take
advantage of new opportunities.

In  addition,  many  of the  employees  that  were  terminated  as  part  of our
restructuring  possessed specific knowledge or expertise,  and that knowledge or
expertise  may prove to have been  important  to our  operations.  In that case,
their absence may create significant difficulties,  particularly if our business
experiences  significant growth. Any failure by us to properly manage this rapid
change in workforce could impair our ability to efficiently manage our business,
to maintain  and develop  important  relationships  with  third-parties,  and to
attract and retain  customers.  It could also cause us to incur higher operating
costs and delays in the  execution of our business  plan or in the  reporting or
tracking of our financial results.

WE MAY NEED TO RAISE  ADDITIONAL  CAPITAL  AND OUR  FUTURE  ACCESS TO CAPITAL IS
UNCERTAIN.

Our  past  revenues  have  been  and our  future  revenues  may  continue  to be
insufficient  to support the expense of our  operations and any expansion of our
business. We may therefore need additional equity or debt capital to finance our
operations.  If we are unable to generate  sufficient cash flows from operations
or to obtain funds through  additional debt or equity financing,  we may have to
reduce some or all of our development and sales and marketing  efforts and limit
the expansion of our business.

We believe our existing cash and cash equivalents will be sufficient to meet our
working capital  requirements  for at least the next twelve months.  Thereafter,
depending on the  development of our business,  we may need to raise  additional
cash for working capital or other expenses. We may also encounter  opportunities
for  acquisitions or other business  initiatives  that require  significant cash
commitments,  or  unanticipated  problems  or  expenses  that could  result in a
requirement for additional cash before that time.

Therefore,  we may seek  additional  funding  through  public or private debt or
equity  financing or from other sources.  We have no commitments  for additional
financing,  and we may experience  difficulty in obtaining  funding on favorable
terms,  if at all. Any financing we obtain may contain  covenants  that restrict
our freedom to operate our business or may require us to issue  securities  that
have  rights,  preferences  or  privileges  senior to Data  I/O's  common  stock
("Common Stock") and may dilute your ownership interest.

WE MAY FACE INCREASED  COMPETITION  AND MAY NOT BE ABLE TO COMPETE  SUCCESSFULLY
WITH CURRENT AND FUTURE COMPETITORS.

Technological  advances have reduced the barriers of entry into the  programming
systems  markets.  We expect  competition to increase from both  established and
emerging  companies.  If we fail to compete  successfully  against  current  and
future sources of competition,  our profitability and financial performance will
be adversely impacted.

IF OUR RELATIONSHIPS WITH SEMICONDUCTOR MANUFACTURERS DETERIORATE,  OUR BUSINESS
MAY BE ADVERSELY AFFECTED.

We work  closely  with  most  semiconductor  manufacturers  to  ensure  that our
programming   systems  comply  with  their  requirements.   In  addition,   many
semiconductor  manufacturers  recommend our programming systems for use by users
of their programmable devices. These working relationships enable us to keep our
programming systems product line up to date and provide end-users with broad and
current  programmable device support.  Our business may be adversely affected if
our relationships with semiconductor manufactures deteriorate.

OUR RELIANCE ON A SMALL  NUMBER OF  SUPPLIERS  COULD RESULT IN A SHORTAGE OF KEY
COMPONENTS, WHICH MAY ADVERSELY AFFECT OUR BUSINESS.

Certain parts used in our products are currently available from either a single
supplier or from a limited number of suppliers. If we cannot develop alternative
sources of these components, if sales of parts are discontinued by the supplier
or we experience deterioration in our relationship with these suppliers, there
may be delays or reductions in product introductions or shipments, which may
materially adversely affect our operating results.

Because we rely on a small number of suppliers for certain parts, we are subject
to  possible  price  increases  by these  suppliers.  Also,  we may be unable to
accurately forecast our production schedule. If we under estimate our production
schedule,  suppliers may be unable to meet our demand for components. This delay
in the supply of key components may  materially  adversely  affect our business.
Over  estimation  of  demand  will lead to excess  inventories  that may  become
obsolete.

The non-automated  programming  system products we acquired when we acquired SMS
in  November  1998  are  currently  manufactured  to  our  specifications  by  a
third-party  foreign  contract  manufacturer.  We may not be able  to  obtain  a
sufficient  quantity of these  products if and when needed,  which may result in
lost sales.

IF WE ARE UNABLE TO ATTRACT AND RETAIN QUALIFIED THIRD-PARTY  DISTRIBUTORS,  OUR
OPERATIONS MAY BE ADVERSELY AFFECTED.

Data  I/O  has  an   internal   sales  force  and  also   utilizes   third-party
representatives,  and distributors.  Therefore, the financial stability of these
distributors is important. Highly skilled professional engineers use most of our
products.  To be effective,  third-party  distributors must possess  significant
technical,  marketing  and sales  resources  and must devote their  resources to
sales  efforts,  customer  education,   training  and  support.  These  required
qualities limit the number of potential third-party  distributors.  Our business
will suffer if we cannot  attract and retain a  sufficient  number of  qualified
third-party distributors to market our products.

OUR  INTERNATIONAL  OPERATIONS  MAY  EXPOSE  US TO  ADDITIONAL  RISKS  THAT  MAY
ADVERSELY AFFECT OUR BUSINESS.

International sales represented 80% of our net revenue for the fiscal year ended
December  31, 2004.  We expect that  international  sales will  continue to be a
significant  portion of our net revenue.  International sales and operations may
fluctuate due to various factors, including:

o migration of manufacturing to low cost geographies

o unexpected changes in regulatory requirements

o tariffs and taxes

o difficulties in staffing and managing foreign operations

o longer average payment cycles and difficulty in collecting accounts receivable

o fluctuations in foreign currency exchange rates

o compliance with applicable export licensing requirements

o product safety and other certification requirements

o difficulties in integrating foreign and outsourced operations

o political and economic instability

The European  Community and European  Free Trade  Association  have  established
certain electronic emission and product safety requirements ("CE"). Although our
products  currently  meet  these  requirements,  failure  to obtain  either a CE
certification  or a waiver for any product may  prevent us from  marketing  that
product in Europe.

We operate  subsidiaries  in Germany,  China and Canada and soon in Brazil.  Our
business and financial  condition is sensitive to currency exchange rates or any
other restrictions imposed on their currencies.  Currency exchange  fluctuations
in Canada,  China, Germany and Brazil may adversely affect our investment in our
subsidiaries.

IF WE ARE UNABLE TO PROTECT  OUR  INTELLECTUAL  PROPERTY  OR  INFRINGE  ON OTHER
INTELLECTUAL  PROPERTY,  WE MAY NOT BE ABLE TO  COMPETE  EFFECTIVELY  OR OPERATE
PROFITABLY.

Data I/O relies on patents,  copyrights, trade secrets and trademarks to protect
our intellectual property, as well as product development and marketing skill to
establish and protect our market  position.  We attempt to protect our rights in
proprietary  software products,  including TaskLink and other software products,
by retaining  the title to and copyright of the software and  documentation,  by
including  appropriate  contractual  restrictions  on use and  disclosure in our
licenses, and by requiring our employees to execute non-disclosure agreements.

Because of the rapidly  changing  technology  in the  semiconductor,  electronic
equipment  and  software  industries,  portions of our products  might  possibly
infringe upon existing patents or copyrights, and we may, therefore, be required
to obtain  licenses or  discontinue  the use of the  infringing  technology.  We
believe that any exposure we may have regarding possible  infringement claims is
a reasonable  business  risk  similar to that assumed by other  companies in the
electronic   equipment   and  software   industries.   However,   any  claim  of
infringement,  with or  without  merit,  could  be  costly  and a  diversion  of
management's attention,  and an adverse determination could adversely affect our
reputation,  preclude  us from  offering  certain  products,  and  subject us to
substantial liability.

WE MAY PURSUE BUSINESS  ACQUISITIONS THAT MAY IMPAIR OUR FINANCIAL  POSITION AND
PROFITABILITY.

We may pursue  acquisitions  of  complementary  technologies,  product  lines or
businesses. Future acquisitions may include risks, such as:

o burdening management and our operating teams during the integration of the
  acquired entity

o diverting management's attention from other business concerns

o failing to successfully integrate the acquired products

o lack of acceptance of the acquired products by our sales channels or customers

o entering markets where we have no or limited prior experience

o potential loss of key employees of the acquired company

o additional burden of support for an acquired programmer architecture

Future acquisitions may also impact Data I/O's financial position.  For example,
we may use significant  cash or incur  additional  debt,  which would weaken our
balance sheet. We may also capitalize  goodwill and intangible  assets acquired,
the impairment of which would reduce our profitability. We cannot guarantee that
future acquisitions will improve our business or operating results.

THE LOSS OF KEY EMPLOYEES MAY ADVERSELY AFFECT OUR OPERATIONS.

As of December 31, 2004, we had 122 employees,  of which 38 were located outside
the U.S. We also utilize independent  contractors for specialty work,  primarily
in  research  and  development,  and in our  Brazilian  operation,  and  utilize
temporary  workers  to  adjust  capacity  to  fluctuating  demand.  Many  of our
employees are highly skilled and our continued  success will depend in part upon
our ability to attract and retain  employees  who can be in great demand  within
the industry.  None of our employees are represented by a collective  bargaining
unit and we  believe  relations  with our  employees  are  favorable,  though no
assurance  can be made that this  will be the case in the  future.  Refer to the
section captioned "Recent Restructuring Activities" above.

FAILURE TO COMPLY WITH REGULATORY  REQUIREMENTS  MAY ADVERSELY  AFFECT OUR STOCK
PRICE AND BUSINESS.

We are subject to numerous  governmental  and stock exchange  requirements  as a
public company,  which we believe we are in compliance with. The  Sarbanes-Oxley
Act of 2002, the Securities and Exchange Commission (SEC) and the Public Company
Oversight Accounting Board (PCOAB) have requirements that we may fail to meet by
required  deadlines or we may fall out of compliance  with, such as the internal
controls  assessment,  reporting and auditor attestation  required under Section
404 of the  Sarbanes-Oxley  Act of 2002 for which we are relying on not being an
accelerated filer. We are in the process of documenting and testing our internal
control  procedures in order to satisfy the  requirements  of Section 404 of the
Sarbanes-Oxley Act of 2002, which requires annual management  assessments of the
effectiveness of our internal controls over financial  reporting and a report by
our Independent  Auditors addressing these assessments.  The compliance date for
non-accelerated  filers has been  extended to the first fiscal year ending on or
after  July  15,  2006.  This  is  a  one-year  extension  from  the  previously
established  July 15,  2005  compliance  date.  Data I/O assumes the status of a
non-accelerated  filer  based on the  aggregate  market  value of the voting and
non-voting  shares held as of June 30, 2005. During the course of our testing we
may identify  deficiencies which we may not be able to remediate in time to meet
the deadline imposed by the  Sarbanes-Oxley  Act of 2002 for compliance with the
requirements of Section 404. In addition, if we fail to achieve and maintain the
adequacy of our internal controls, as such standards are modified,  supplemented
or amended from time to time,  we may not be able to ensure that we can conclude
on an ongoing basis that we have  effective  internal  controls  over  financial
reporting  in  accordance  with Section 404 of the  Sarbanes-Oxley  Act of 2002.
Moreover,  effective  internal  controls,  particularly those related to revenue
recognition,  are necessary for us to produce reliable financial reports and are
important  to help  prevent  financial  fraud.  If we  cannot  provide  reliable
financial  reports or prevent fraud, our business and operating results could be
harmed,  investors could lose confidence in our reported financial  information,
and the trading price of our stock could drop significantly. Our failure to meet
requirements  and exchange  listing  standards may result in actions such as the
delisting of our stock impacting our stock's liquidity; SEC enforcement actions;
and result in securities claims and litigation.

OUR STOCK  PRICE MAY BE VOLATILE  AND, AS A RESULT,  YOU MAY LOSE SOME OR ALL OF
YOUR INVESTMENT.

The stock prices of technology  companies  tend to fluctuate  significantly.  We
believe factors such as  announcements of new products by us or our competitors,
quarterly  variations  in  financial  results and sales of our common  stock may
cause the market price of Data I/O's Common Stock to fluctuate substantially. In
addition, overall volatility in the stock market, particularly in the technology
company sector, is often unrelated to the operating performance of companies. If
these market fluctuations  continue in the future, they may adversely affect the
price of Data I/O's Common Stock.



                 SPECIAL NOTE ABOUT FORWARD-LOOKING INFORMATION

This  prospectus and the documents  incorporated by reference in this prospectus
contain forward-looking  statements.  These forward-looking statements are based
on our current  expectations,  estimates  and  projections  about our  industry,
management's  beliefs  and  certain  assumptions  made  by  us.  Words  such  as
"anticipate,"   "expect,"   "intend,"  "plan,"  "believe,"  "seek,"  "estimate,"
"predict," "continue," "will" and "may" and variations of these words or similar
expressions  are  intended  to  identify   forward-looking   statements.   These
statements  reflect the views of our  management at the time they are made based
on  information  currently  available to  management.  These  statements are not
guarantees of future performance and are subject to certain risks, uncertainties
and  assumptions  that are difficult to predict.  Therefore,  our actual results
could   differ   materially   from  those   expressed  or   forecasted   in  any
forward-looking  statements as a result of a variety of factors, including those
set forth in "Risk Factors" above and elsewhere in, or incorporated by reference
into, this prospectus.  Except as required by law, we undertake no obligation to
update  publicly  any  forward-looking  statements  for any reason,  even if new
information becomes available or other events occur in the future.

                                 USE OF PROCEEDS

The  shares  of  Common  Stock  offered  by  this  prospectus  will  be  sold or
distributed  by the  selling  shareholders,  and the selling  shareholders  will
receive all of the  proceeds,  if any, from the sales of such shares by them. We
will not receive any proceeds from the sale or  distribution of the Common Stock
by the selling  shareholders.  We could receive up to $339,625 in gross proceeds
from the cash  exercise of certain  options by the selling  shareholders,  which
proceeds would be used for general corporate purposes.

                              SELLING SHAREHOLDERS

This  prospectus  covers the  offering of shares of Common  Stock by the selling
shareholders  named below.  This prospectus is part of a registration  statement
filed in order to register, on behalf of the selling shareholders,  an aggregate
total of  1,050,000  shares of Common  Stock.  The  following  are the number of
shares  beneficially  owned by the selling  shareholders prior to this offering;
the number of shares to be offered for the selling shareholders'  accounts;  and
the  number  of  shares  to be  owned  by  the  selling  shareholders  following
completion of the offering:




                                   Number of Shares     Number of Shares      Number of Shares       Percentage of
                                     Owned Before            Offered             Owned Upon        Shares Owned Upon
             Name                      Offering                                Completion of         Completion of
                                                                                  Offering             Offering
-------------------------------- --------------------- -------------------- --------------------- --------------------
                                                                                                       
Fredrick R. Hume                     243,308(1)             100,000            143,308(2)             1.75%(3)
-------------------------------- --------------------- -------------------- --------------------- --------------------
Bisco Industries, Inc.               694,916(4)             680,000             14,916(2)             0.18%(3)
-------------------------------- --------------------- -------------------- --------------------- --------------------
Bisco Industries, Inc. Profit        273,564(4)             270,000              3,564(2)             0.04%(3)
Sharing and Savings Plan
-------------------------------- --------------------- -------------------- --------------------- --------------------
Total                              1,211,788(1)(4)        1,050,000(1)         161,788(2)             1.97%(3)
-------------------------------- --------------------- -------------------- --------------------- --------------------


(1)  Includes options to purchase 125,000 shares exercisable within 60 days.

(2)  This figure  assumes that the selling  shareholders  will sell all of their
     shares  available  for sale during the  effectiveness  of the  registration
     statement that includes this prospectus.  The selling  shareholders are not
     required to sell their shares. See "Plan of Distribution."

(3)  Based on 8,199,678 shares of Common Stock  outstanding as of March 21, 2005
     as reported by the Company in its annual report on Form 10-K filed with the
     SEC on March 28, 2005.

(4)  The holding  shown is as of April 20, 2005, as reported to Data I/O by Glen
     F.  Ceiley  on  behalf  of  Bisco  Industries,  Inc.  ("Bisco")  and  Bisco
     Industries,  Inc.  Profit Sharing and Savings Plan (the "Bisco Plan").  Mr.
     Glen Ceiley is the President, a director, and the sole shareholder of Bisco
     and is also the sole trustee of the Bisco Plan.

Mr. Glen Ceiley has been a director of Data I/O since February 1999. Since 1973,
Mr.  Ceiley  has  been  the  President  and  Chief  Executive  Officer  of Bisco
Industries, a distributor of fasteners and electronic components, which, as part
of a group,  currently owns  approximately  11.85% of the Company's  outstanding
Common Stock.

Frederick R. Hume became  President and Chief  Executive  Officer of Data I/O on
February 23, 1999. He has been a director of Data I/O since January 1999.



                              PLAN OF DISTRIBUTION

We are  registering  the shares on behalf of the selling  shareholders.  When we
refer to selling shareholders,  we intend to include donees and pledgees selling
shares  received  from a  named  selling  shareholder  after  the  date  of this
prospectus.  All costs, expenses and fees in connection with the registration of
the  shares  offered  under  this  Registration  Statement  will be borne by us.
Brokerage  commissions and similar selling expenses, if any, attributable to the
sale of shares will be borne by the selling shareholders. Sales of shares may be
effected by the selling  shareholders  from time to time in one or more types of
transactions  (which may  include  block  transactions)  on the Nasdaq  National
Market,  the  Nasdaq  SmallCap  Market,  in  the  over-the-counter   market,  in
negotiated  transactions,  through put or call options transactions  relating to
the shares,  through short sales of shares,  or a combination of such methods of
sale, at market prices prevailing at the time of sale, or at negotiated  prices.
Such  transactions  may or may not  involve  brokers  or  dealers.  The  selling
shareholders  have  advised us that they have not entered  into any  agreements,
understandings or arrangements with any underwriters or broker-dealers regarding
the sale of their securities, nor is there an underwriter or coordinating broker
acting  in  connection   with  the  proposed  sale  of  shares  by  the  selling
shareholders.

The selling shareholders may effect such transactions by selling shares directly
to  purchasers  or to or  through  broker-dealers,  which  may act as  agents or
principals.  Such  broker-dealers  may  receive  compensation  in  the  form  of
discounts,  concessions,  or commissions  from the selling  shareholders  and/or
purchasers of shares for whom such  broker-dealers  may act as agents or to whom
they  sell  as  principal,  or  both  (which  compensation  as  to a  particular
broker-dealer might be in excess of customary commissions).

The selling  shareholders and any broker-dealers that act in connection with the
sale of shares  might be deemed  to be  "underwriters"  within  the  meaning  of
Section 2(11) of the Securities Act of 1933, as amended (the "Securities  Act"),
and any commissions received by such broker-dealers and any profit on the resale
of  shares  sold by them  while  acting  as  principals  might be  deemed  to be
underwriting  discounts or  commissions  under the  Securities  Act. The selling
shareholders  may agree to indemnify  any agent,  dealer or  broker-dealer  that
participates  in  transactions  involving  sales  of  the  shares  against  some
liabilities arising under the Securities Act.

Because the selling  shareholders may be deemed to be "underwriters"  within the
meaning of Section 2(11) of the Securities Act, the selling shareholders will be
subject to the prospectus  delivery  requirements of the Securities Act. We have
informed  the selling  shareholders  that the  anti-manipulative  provisions  of
Regulation M promulgated  under the Securities  Exchange Act of 1934, as amended
(the "Exchange Act") may apply to their sales in the market.

Selling  shareholders  also may  resell  all or a portion  of the shares in open
market transactions in reliance upon Rule 144 under the Securities Act, provided
they meet the criteria and conform to the requirements of such Rule.

Upon being notified by any selling shareholder that any material arrangement has
been entered into with a  broker-dealer  for the sale of shares  through a block
trade, special offering,  exchange  distribution or secondary  distribution or a
purchase by a broker or dealer, we will file a supplement to this prospectus, if
required, under Rule 424(b) of the Act, disclosing:

o the name of each selling shareholder(s) and of the participating
  broker-dealer(s);
o the number of shares involved;
o the price at which the shares were sold;
o the  commissions paid or discounts or concessions allowed to the
  broker-dealer(s), where applicable;
o that the broker-dealer(s) did not conduct any investigation to verify
  information set out or incorporated by reference in this prospectus; and
o other facts material to the transaction.

In  addition,  upon being  notified by any selling  shareholder  that a donee or
pledgee intends to sell more than 500 shares,  we will file a supplement to this
prospectus.

                             LEGALITY OF SECURITIES

Dorsey & Whitney  LLP,  Seattle,  Washington,  has  provided an opinion that the
shares of Common Stock offered by this prospectus are legally issued, fully paid
and nonassessable.

                                     EXPERTS

The consolidated financial statements and schedule of Data I/O Corporation as of
December  31,  2004,  2003 and 2002 and for each of the years in the  three-year
periods  ended  December 31, 2003 and 2004 have been  incorporated  by reference
herein and in the  registration  statement in reliance  upon the report of Grant
Thornton LLP, an independent registered public accounting firm,  incorporated by
reference  herein,  and upon the authority of said firm as experts in accounting
and auditing



                       WHERE YOU CAN FIND MORE INFORMATION

We have filed a registration  statement on Form S-3 with the SEC to register the
sale of the shares of Common Stock offered by the selling shareholders under the
Securities Act. This prospectus,  which is a part of the registration statement,
does not contain all of the information that is in the  registration  statement.
Statements made in this prospectus as to the content of any contract,  agreement
or other document are not necessarily complete. Some contracts,  agreements,  or
other  documents  are filed as exhibits to the  registration  statement  or to a
document incorporated by reference in this prospectus. In those cases, investors
should refer to such exhibits for more complete descriptions.

We file annual,  quarterly and special reports, proxy and information statements
and other  information with the SEC. The public may read and copy, at prescribed
rates, any materials we file with the SEC, including the registration  statement
and  its  exhibits  and  any  documents  incorporated  by  reference  into  this
prospectus,  at the SEC's offices at: Public  Reference  Room, 450 Fifth Street,
N.W.,  Washington,  D.C. 20549.  For information on how to obtain such documents
from the SEC,  investors  may  telephone  the  SEC's  Public  Reference  Room at
1-800-SEC-0330.  The SEC Internet site at http://www.sec.gov  contains materials
that we file with the SEC in  electronic  version  through the SEC's  Electronic
Data Gathering, Analysis and Retrieval (EDGAR) system.

We are allowed by the SEC to "incorporate by reference"  information  filed with
the SEC,  which means that we can disclose  important  information  to people by
referring  them to other  documents  that we file with the SEC. The  information
incorporated by reference is considered to be part of this  prospectus.  We have
filed the following  documents with the SEC pursuant to the Exchange Act and are
incorporating them by reference into this prospectus:

(a)  the Company's Annual Report on Form 10-K for the fiscal year ended December
     31, 2004;

(b)  the  Company's  Annual  Report on Form  10-K/A  for the  fiscal  year ended
     December 31, 2003;

(c)  the  Company's  Current  Report on Form 8-K filed on February  14, 2005 and
     February 18, 2005; and

(d)  the  description of the Company's  Common Stock, no par value per share, as
     contained  in Item 1 of the  Registration  Statement  on Form 8-A  filed on
     April 29, 1982  including  any amendment or report filed for the purpose of
     updating  such   description   filed  for  the  purpose  of  updating  such
     description.

We also incorporate all documents we subsequently  file with the SEC pursuant to
Section  13(a),  13(c),  14, or 15(d) of the Exchange Act after the date of this
prospectus and prior to the  termination of this  offering.  The  information in
these documents will update and supersede the information in this prospectus.

We will provide at no cost to each person to whom this  prospectus is delivered,
including any beneficial owner,  upon written or oral request,  a copy of any or
all of  the  information  that  has  been  incorporated  by  reference  in  this
prospectus  but not  delivered  with this  prospectus.  Investors  should direct
requests to Joel S. Halten,  Data I/O  Corporation,  10525 Willows Road NE, P.O.
Box 97046, Redmond,  Washington 98073-9746,  telephone:  (425) 881-6444. Our web
site is www.dataio.com.



                                     PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION

The following are the estimated  expenses in connection with the distribution of
the securities being registered:

Securities and Exchange Commission registration fee.........................$436
Legal fees.............................................................. $10,000
Accounting fees and expenses..............................................$9,500
                                                                    ------------

Total....................................................................$19,936

================================================================================
All expenses, except the SEC fees, are estimates.

The selling  shareholders  will not bear any portion of the foregoing  expenses,
but will  pay fees in  connection  with  the sale of the  Common  Stock in those
transactions  completed to or through  securities  brokers and/or dealers in the
form of markups, markdowns, or commissions.

ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS

The Company's  articles of  incorporation  and bylaws limit the liability of the
Company's  directors to the fullest extent permitted by the Washington  business
corporation  act (the "WBCA") as it currently  exists or as it may be amended in
the future.  Consequently,  subject to the WBCA,  no director will be personally
liable to the Company or its shareholders  for monetary  damages  resulting from
his or her conduct as a director, except liability for:

o acts or omissions involving intentional misconduct or knowing violations of
  law;

o unlawful distributions; or

o transactions from which the director personally receives a benefit in money,
  property or services to which the director is not legally entitled.

The  Company's  articles  of  incorporation  also  provide  that the Company may
indemnify any individual made a party to a proceeding because that individual is
or was a director or officer of the Company,  and this right to  indemnification
will continue as to an individual who has ceased to be a director or officer and
will inure to the benefit of his or her heirs, executors or administrators.  Any
subsequent repeal of or modification to the Company's  articles of incorporation
will not  adversely  affect any right of a director or officer of ours who is or
was a director  or officer at the time of such  repeal or  modification.  To the
extent the  provisions of the Company's  articles of  incorporation  provide for
indemnification  of  directors  or officers for  liabilities  arising  under the
Securities Act, those  provisions are, in the opinion of the SEC, against public
policy as expressed in the Securities Act and therefore unenforceable.

The Company's articles of incorporation and bylaws provide that the Company will
indemnify its  directors and officers and may indemnify its other  employees and
agents to the fullest extent permitted by law. The Company's directors, officers
and  employees  also may be  indemnified  against  liability  they may incur for
serving in that capacity pursuant to a liability  insurance policy maintained by
the Company for such purpose.

ITEM 16. EXHIBITS

The following documents are included as exhibits to this Registration Statement,
pursuant to Item 601 of regulation S-K.

Exhibit No.                    Title of Document
---------- ---------------------------------------------------------------------
  5.1*     Opinion of Dorsey & Whitney LLP.

  23.1     Consent of Grant Thornton LLP, an independent registered public
           accounting firm.

  23.2*    Consent of Dorsey & Whitney LLP (contained in Exhibit 5.1).

  23.3     Consent of Grant Thornton LLP, an independent registered public
           accounting firm.

  24.1*    Power of Attorney (included in signature page).

*Previously filed
--------------------------------------------------------------------------------

ITEM 17. UNDERTAKINGS

The undersigned registrant hereby undertakes:

     (1)  To file,  during any period in which offers or sales are being made, a
          post-effective amendment to this Registration Statement:

          (i)  To include any  prospectus  required  by section  10(a)(3) of the
               Securities Act;

          (ii) To reflect in the  prospectus  any facts or events  arising after
               the  effective  date of the  registration  statement (or the most
               recent post-effective  amendment thereof) which,  individually or
               in  the  aggregate,   represent  a  fundamental   change  in  the
               information   set   forth   in   the   registration    statement.
               Notwithstanding the foregoing, any increase or decrease in volume
               of  securities  offered (if the total dollar value of  securities
               offered  would not  exceed  that  which was  registered)  and any
               deviation  from  the low or  high  end of the  estimated  maximum
               offering  range may be reflected in the form of prospectus  filed
               with the SEC  pursuant to Rule 424(b) if, in the  aggregate,  the
               changes in volume and price  represent  no more than a 20% change
               in  the  maximum  aggregate  offering  price  set  forth  in  the
               "Calculation  of   Registration   Fee"  table  in  the  effective
               registration statement;

          (iii)To include any material  information  with respect to the plan of
               distribution   not  previously   disclosed  in  the  registration
               statement  or any  material  change  to such  information  in the
               registration statement;

     provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) of this section
     do not apply if the registration statement is on Form S-3, Form S-8 or Form
     F-3,  and the  information  required  to be  included  in a  post-effective
     amendment by those  paragraphs is contained in periodic  reports filed with
     or furnished to the SEC by the registrant pursuant to section 13 or section
     15(d) of the  Exchange  Act  that  are  incorporated  by  reference  in the
     registration statement.

     (2)  That,  for  the  purpose  of  determining   any  liability  under  the
          Securities Act, each such post-effective  amendment shall be deemed to
          be a new  registration  statement  relating to the securities  offered
          therein,  and the  offering of such  securities  at that time shall be
          deemed to be the initial bona fide offering thereof.

     (3)  To remove from registration by means of a post-effective amendment any
          of  the  securities  being  registered  which  remain  unsold  at  the
          termination of the offering.

The undersigned  registrant  hereby undertakes that, for purposes of determining
any liability under the Securities Act, each filing of the  registrant's  annual
report  pursuant to section  13(a) or section  15(d) of the  Exchange  Act (and,
where  applicable,  each  filing of an employee  benefit  plan's  annual  report
pursuant to section 15(d) of the Exchange Act) that is incorporated by reference
in the registration statement shall be deemed to be a new registration statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

Insofar as indemnification  for liabilities arising under the Securities Act may
be permitted to directors,  officers and  controlling  persons of the registrant
pursuant to the foregoing  provisions,  or otherwise,  the  registrant  has been
advised that in the opinion of the SEC such  indemnification  is against  public
policy as expressed in the Securities Act and is, therefore,  unenforceable.  In
the event that a claim for indemnification  against such liabilities (other than
the  payment by the  registrant  of  expenses  incurred  or paid by a  director,
officer or controlling person of the registrant in the successful defense of any
action, suit or proceeding) is asserted by such director, officer or controlling
person in connection with the securities being registered,  the registrant will,
unless  in the  opinion  of  its  counsel  the  question  has  been  settled  by
controlling  precedent,  submit  to a  court  of  appropriate  jurisdiction  the
question  whether  such  indemnification  by  it is  against  public  policy  as
expressed in the Securities  Act and will be governed by the final  adjudication
of such issue.



                                   SIGNATURES

Pursuant to the  requirements  of the Securities  Act, the registrant  certifies
that it has reasonable  grounds to believe that it meets all of the requirements
for filing on Form S-3 and has duly caused  this  Registration  Statement  to be
signed on its behalf by the undersigned,  thereunto duly authorized, in Redmond,
Washington, on April 25, 2005.

                                 DATA I/O CORPORATION


                                 By:   
                                 Joel S. Hatlen
                                 Vice President, Chief Financial Officer,
                                 Secretary and Treasurer

Pursuant to the requirements of the Securities Act, this Registration  Statement
has been signed  below by the  following  persons in the  capacities  and on the
dates indicated.

Signature               Title                                        Date
                                                                 April 25, 2005
//s//Frederick R. Hume   Chief Executive Officer,
                        President and a director
                        (Principal Executive Officer)

//s//Joel S. Hatlen     Vice President of Finance,               April 25, 2005
                        Chief Financial Officer,
                        Secretary and Treasurer
                        (Principal Financial Officer and Accounting Officer)

       *               Director                                  April 25, 2005
Glen F. Ceiley

       *               Director
Daniel A. DiLeo                                                  April 25, 2005

       *               Director                                  April 25, 2005
Paul A. Gary

       *               Director                                  April 25, 2005
Edward D. Lazowska

       *               Director                                  April 25, 2005
Steven M. Quist

       *               Director                                  April 25, 2005
William R. Walker

*By //s//Joel S. Hatlen
    Attorney-in-fact



                                  EXHIBIT INDEX

Exhibit No.                            Title of Document
------------ -------------------------------------------------------------------
 5.1*        Opinion of Dorsey & Whitney LLP.

 23.1        Consent of Grant Thornton LLP, an independent registered public
             accounting firm.

 23.2*       Consent of Dorsey & Whitney LLP (contained in Exhibit 5.1).

 23.3        Consent of Grant Thornton LLP, an independent registered public
             accounting firm.

 24.1        Power of Attorney (included in signature page).

*Previously filed



Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We have  issued our report  dated  March 11,  2005  accompanying  the  financial
statements of Data I/O  Corporation  appearing in the Annual Report on Form 10-K
of the Company for the year ended  December  31, 2004 which is  incorporated  by
reference in this Amendment No. 1 to this Registration  Statement. We consent to
the   incorporation  by  reference  in  this   Registration   Statement  of  the
aforementioned report and to the use of our name as it appears under the caption
"Experts."

Seattle, Washington
April 22, 2005



Exhibit 23.3

Consent of Independent Registered Public Accounting Firm

We have  issued  our  report  dated  February  6, 2004  (March 5, 2005 as to the
effects of the  restatement  described  in Note 3)  accompanying  the  financial
statements of Data I/O Corporation appearing in the Annual Report on Form 10-K/A
of the Company for the year ended  December  31, 2003 which is  incorporated  by
reference in this Amendment No. 1 to this Registration  Statement. We consent to
the   incorporation  by  reference  in  this   Registration   Statement  of  the
aforementioned report and to the use of our name as it appears under the caption
"Experts."

Seattle, Washington
April 22, 2005