31-bit addressing

purushoth_jp · New User Joined: 12 Dec 2004 Posts: 22

1.
can anybody help me to find out what is 31-bit addressing. it was introduced in cobol new verion. how we can implement this in cobol.

2. what is data independence (logical and physical) plz don't give me the definition. plz explain me.

jz1b0c · Posted: Mon Dec 13, 2004 9:55 pm

Great Day!

Each program has an addressing mode (AMODE) and residency mode (RMODE) associated with it at link-edit time. The AMODE can be 24, 31, or ANY. Many programs from the days of MVS Version 1 still execute in 24-bit mode, but programs which need to address storage above the 16 megabyte line must execute in 31-bit mode. During execution, the mode can be changed using the BSM or BASSM instructions, but it is more common for each program to execute in one mode only - the initial mode is set by the fetch process depending on the AMODE of the program. At any time, the current mode is indicated by the high-order bit of the next instruction address in the PSW, which is 1 in 31-bit mode and 0 in 24-bit mode. this is available in releases from ESA.this is related to hardware

jz1b0c · Posted: Tue Dec 14, 2004 1:14 am

Great Day!

Regarding data independence, please go thru the link,
I got it from google search

purushoth_jp · New User Joined: 12 Dec 2004 Posts: 22

hi masade

thanks for ur valuable reply.