SEC FORM 3

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

Dalton Stephen P

(Last)

(First)

(Middle)

1650 TECHNOLOGY DRIVE

SUITE 700

(Street)

SAN JOSE

95110

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
03/29/2007

3. Issuer Name and Ticker or Trading Symbol
QUANTUM CORP /DE/ [ QTM ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	SVP, Tiered Storage Solutions

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock⁽¹⁾	20,000	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
Non-qualified stock option	02/01/2006⁽²⁾	03/22/2012	Common Stock⁽³⁾	150,000	$2.76	D
Non-qualified stock option	07/01/2005⁽⁴⁾	05/31/2012	Common Stock⁽³⁾	50,000	$2.62	D
Non-qualified stock option	11/16/2007⁽²⁾	11/16/2013	Common Stock⁽³⁾	150,000	$2.38	D
Restricted Stock Units⁽⁶⁾	08/22/2007⁽⁵⁾	⁽⁵⁾	Common Stock⁽⁶⁾	80,000	$0.0	D

Explanation of Responses:

1. Restricted Stock Award granted on October 25, 2005 under Rule 16b-3. Restricted stock will vest 25% annually over four years beginning on October 1, 2006.

2. Stock option vests 25% on the first anniversary and monthly thereafter at a rate of 1/48th per month for the remaining three years.

3. Right to buy under Rule 16b-3 plan.

4. Stock option vests monthly in equal installments over 4 years.

5. Restricted Stock Units will vest over a period of two years, as follows: the first 50% will vest on August 22, 2007 and the remaining 50% on August 22, 2008.

6. Restricted Stock Units convert to shares of Common Stock on a 1-for-1 basis.

	Shawn Hall	04/06/2007
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.