DEF SEG Statement Details
 
Syntax
  DEF SEG [=address]
 
For BLOAD, BSAVE, CALL ABSOLUTE, PEEK, and POKE, address is used as
the segment. The address is a numeric expression returning an unsigned
integer in the range 0-65,535. A value outside this range produces the
error message "Illegal function call." The previous segment is
retained if an error occurs. If you omit address, the BASIC data
segment is used.
 
Be sure to separate DEF and SEG with a space. Otherwise, BASIC
interprets the statement to mean "assign a value to the variable
DEFSEG."
 
Differences from BASICA
 
In QuickBASIC, the CALL and CALLS statements do not use the segment
address set by DEF SEG.