QUEUE FOR A DEVICE HANDLER

LQE: Q6
CQE: Q1
        +------------------+
Q1:     |        Q2        |
        +------------------+        <-- THIS I/O TRANSFER IS CURRENTLY
        |  JOB NUMBER = 0  |            IN PROGRESS; THE MONITOR DOES
        | (BACKGROUND JOB) |            NOT PREEMPT IT WITH A QUEUE
        +------------------+            ELEMENT FOR A HIGHER PRIORITY
                 |                      JOB.
        +------------------+
Q2:     |        Q3        |
        +------------------+
        |  JOB NUMBER = 16 |
        | (FOREGROUND JOB) |
        +------------------+
                 |
        +------------------+
Q3:     |        Q4        |             NEW QUEUE ELEMENT
        +------------------+
        |  JOB NUMBER = 16 |            +------------------+
        | (FOREGROUND JOB) |            |       ?          |
        +------------------+            +------------------+
                 |          <-----------|  JOB NUMBER = 16 |
        +------------------+            | (FOREGROUND JOB) |
Q4:     |        Q5        |            +------------------+
        +------------------+
        |  JOB NUMBER = 14 |
        |  (SYSTEM JOB 6)  |
        +------------------+
                 |
        +------------------+
Q5:     |        Q6        |
        +------------------+
        |  JOB NUMBER = 12 |
        |  (SYSTEM JOB 5)  |
        +------------------+
                 |
        +------------------+
Q6:     |         0        |
        +------------------+        <-- THIS ELEMENT IS THE LAST ONE
        |  JOB NUMBER = 0  |            IN THE QUEUE; ITS LINK WORD
        | (BACKGROUND JOB) |            IS 0.
        +------------------+