Topic       : The ATARI Compendium
Author      : Scott Sanders / JAY Software
Version     : 1.25 (20/6/2003)
Subject     : Documentation
Nodes       : 1117
Index Size  : 32614
HCP-Version : 6
Compiled on : Atari
@charset    : UTF-8
@lang       : en
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@help       : %About
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View Ref-FilePhysbase()
Logbase()                                                             XBIOS

Syntax

VOIDP Logbase( VOID )

Function      Logbase() returns a pointer to the base of the logical
              screen.

Opcode        3 (0x03)

Availability  All TOS versions.

Binding       move.w   #$03,-(sp)
              trap     #14
              addq.l   #2,sp

Return Value  Logbase() returns a pointer to the base of the logical
              screen.

Comments      The logical screen should not be confused with the physical
              screen. The logical screen is the memory area where the VDI
              does any drawing. The physical screen is the memory area
              where the video shifter gets its data from. Normally they
              are the same; however, keeping the addresses separate
              facilitates screen flipping.

See Also      Physbase()