PROHVK05@TREARN.BITNET (Bahri Bora BALI AG) (12/08/89)
Hello.. I've seen a statement part like X'608'(0,0) in an assembler program. R0 has been used for NUCON. (USING NUCON,R0) What information is contained starting from address X'608' in CMS nucleus. I didn't find any information which makes sense. Any ideas ? Thank you.. -Bora
VALDIS@VTVM1.CC.VT.EDU (Valdis Kletnieks) (12/09/89)
On Fri, 8 Dec 89 13:26:20 TUR Bahri Bora BALI AG said: >Hello.. I've seen a statement part like X'608'(0,0) in an assembler program. >R0 has been used for NUCON. (USING NUCON,R0) What information is contained >starting from address X'608' in CMS nucleus. I didn't find any information >which makes sense. Any ideas ? Thank you.. > >-Bora Bora - In general, anybody who codes X'608'(0,0) should be shot by a firing squad at dawn. The problem is that in general, fixed offsets aren't. Just a few weeks ago, we had to fix a problem here for the HPO/5 version of CMS, where the 'USERSECT' area had moved in memory compared to HPO/4.2, and we had code that only knew about it as a fixed address. In VM/XA SP2, x'608' in NUCON is SYSNAME - the name of the system you gave on the IPL command - if you said 'IPL CMS', it has a CL8'CMS' in it. If you said 'IPL CMSTEST', it has CL8'CMSTEST'. A handy value to have around... Of course, SYSNAME could be at other offsets for other releases. The *proper* thing to do is of course reference it using the handy labels in the NUCON macro. If nothing else, it makes for easier code: NI x'19'(0),x'FC' turn off run bit versus NI EXTOPSW+1,X'FF'-X'02' turn off run bit. Plus, if you use the mapping macros, you can (a) look at the comments that they provide on what the field is and (b) when a new release of CMS comes out, you have at least a snowball's chance you-know-where of having it still work after you re-assemble against the new maclibs... Valdis Kletnieks
B00H@UNB.CA ("B00H ", The poor little hacker boy from Parrsboro) (12/11/89)
Sorry, I am reaslly at a loss to explain that instruction, however, I will ask around a few friends of mine, here at the CS department. They will have a few good ideas as to what it will do. Layton