Microsoft KB Archive/25261
Using the Combine Type AT to Load Data at a Specific Address ID Number: Q25261
1.25 1.27 3.01 5.00 MS-DOS
Can I specify a physical load address for a data segment using AT?
No. The AT combine type can only be used to make templates. Data initialized within a segment using AT will not be put into memory. In fact, the segment will not be assigned any memory. AT can only be used to set up a template so that variables can be made to have specific addresses in memory.
The following example shows how to use AT to set a FAR label to a specific address:
ASEG SEGMENT BYTE AT 0000H
TEMPLATE_LABEL: LABEL FAR ASEG ENDS