DEF SEG

[DEF SEG](DEF SEG) is used to define the area in memory to access QB64's emulated conventional memory.

PageLegacySupport

• QB64 implements memory access using _MEM and related functions. For that reason, [DEF SEG](DEF SEG) isn't recommended practice anymore and is supported to maintain compatibility with legacy code.

Syntax

[DEF SEG](DEF SEG) [=][{segment|VARSEG(variable}]

Description

• Used to set the pointer to a memory area of a variable/array or register.
• PEEK and POKE require a segment memory address (often just 0) without using VARSEG.
• Important segments using PEEK and POKE include &HB800 (text segment) and &HA000 (graphics segment).
• BSAVE and BLOAD require a VARSEG reference to the grahic array(0 index) used.
• Always use DEF SEG when the procedure is completed, in order to reset the segment to QBasic's default value.
• [DEF SEG](DEF SEG), VARSEG, VARPTR, PEEK and POKE access QB64's emulated 16 bit conventional memory block. It is highly recommended to use QB64's _MEM memory system to avoid running out of memory.

See Also

• [DEF SEG = 0](DEF SEG = 0)
• VARPTR, VARSEG
• PEEK, POKE
• BSAVE, BLOAD