Some processors do not allow the data space or hiperspace to start
at zero; these spaces start at address 4096 bytes. When you use DSPSERV
CREATE, you can count on the origin of the data space or hiperspace
staying the same within the same IPL. To learn the starting address,
either:
- Create a data space 1 block larger than you need and then assume
that the space starts at address 4096, or
- Use the ORIGIN parameter.
If you use ORIGIN, the system returns the beginning address of
the data space or hiperspace at the location you specify.
Unless you specify a size of 2 gigabytes and the processor does
not support an origin of zero, the system gives you the size you request,
regardless of the location of the origin.
An example of the problem you want to avoid in addressing data
space storage is as follows:
- Suppose a program creates a data space of 1 megabyte and assumes
the data space starts at address 0 when it really begins at the address
4096. Then, if the program uses an address lower than 4096 in the
data space, the system abends the program.