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[jacky_ying]

Hi,everyone,I am new to ASM,I am confused about some concepts,Can you please clearify it for me,thanks

1. What is the exact different between A-type address constant and V-type address constant except below
a). A-type address constant can be relocatable address or absoluted address, V-type addess constant must be relocatable address
b).the length of V-type address constant must be 4 byte,can't be changed, on the other hand, we can define the length of A-type address constant if it is absoluted address(if not,may be get a warning)
so, all V-type address constant in programs can be replace by A-type address constant plus EXTRN,right?

2.Can you explain 'storage protect key' and 'PSW key' and how does it work? or suggest me a suitable books?

[kolusu]

Jacky_ying,

1. Check these links which will answer your queries.

http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/ASMR1003/5.17.8.7?

http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/ASMR1003/B.0?DT=20000721044852


2.

http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DZ9ZR003/3.0?DT=20040504121320

http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DZ9ZR003/4.2?DT=20040504121320

Hope this helps...

Cheers

Kolusu
_________________
Kolusu
www.linkedin.com/in/kolusu