TAL Programmer's Guide

Using Extended Data Segments
Managing Addressing
B–20 096254 Tandem Computers Incorporated
C-Series Extended Segment Allocation Program
Example B-3 shows a C-series version of the previous D-series extended segment
allocation program. This example is not portable to future software platforms:
Example B-3. C-Series Extended Segment Allocation Program
?INSPECT, SYMBOLS
?SOURCE $SYSTEM.SYSTEM.EXTDECS0 (
? ALLOCATESEGMENT, USESEGMENT)
PROC alloc_xsegment MAIN;
BEGIN
DEFINE error = ! ...! #; !Error handling routine
INT .EXT px := %2000000D; !Initialize extended pointer
! to start of extended segment
INT s;
!Lots of code
s := ALLOCATESEGMENT (0, 4096D);
!Allocate extended segment 0;
! assign status value to S;
! request 2 pages (4K bytes)
! of extended memory
IF s <> 0 THEN error; !Continue if segment 0 is
! allocated else return error
CALL USESEGMENT (0); !Make segment 0 the current
! extended segment
px := 5; !Assign 5 to first word of
! segment 0
s := ALLOCATESEGMENT (1, 4096D);
!Allocate extended segment 1;
! assign status value to S;
! request 2 pages (4K bytes)
! of extended memory
IF s <> 0 THEN error; !Continue if segment 1 is
! allocated else return error
CALL USESEGMENT (1); !Make segment 1 the current
! extended segment
px := 2; !Assign 2 to first word of
! extended segment 1
!Lots more code
END;