Set system variables
Tools tab > Settings group > (Set system variable), 'SETVAR
Set and view system variables.
Do the following:
System variables store information about the drawing and system status. Certain variables, such as LINETYPE, cannot be changed with the SETVAR command. Some variables, such as GRIDSPACING, are easier to change with a specific command, like the Grid function.
Setting system variables via command line
You can set system variable values via the command line as long as the values are not read-only. When you enter a system variable name in the command line with $, you can see the current value. You can change the value by entering the new value in the command line.
For example: you want to change the arc precision to 5:
>$arcprecision
Arcprecision=5
You can use asterisks and question marks, as in layer names.