OS390 versus zOS.

[Anushka Sharma]

Hi,

My question is perhaps offtopic but this has been haunting me. What is more appropriate to use between OS390 versus zOS? I have seen people are using these terms, usually, interchangibly. Is not it that OS390 is among the initial releases of the operating system? And it's zOS now.

[enrico-sorichetti]

the operating system names change to follow roughly the architecture of the hardware .

have a look at
http://www.demorton.com/Tech/$OSTL.pdf

[Robert Sample]

Is not it that OS390 is among the initial releases of the operating system?

LOL -- completely ignoring MVS/ESA, MVS/XA, MVS, MVT, MFT and so forth. OS/390 did not come along until 1995 and the first IBM mainframe operating system in this line came out in 1964. Operating system names tend to hang around -- if you look at the documentation for z/OS, IBM still has the term MVS in some of the manual titles -- even though MVS came out in 1974 and hasn't been the name of an operating system since OS/390 came out.

[Anushka Sharma]

Thanks.

I have seen people using MVS also but not MFT or MVT. But as you said, IBM documents still use MVS, perhaps that makes to use it.

[enrico-sorichetti]

MVS also but not MFT or MVT.

because ...
MVS stands for Multiple Virtual Storage

MFT stands for Multiprogramming with a Fixed number of Tasks
MVT stands for Multiprogramming with a Variable number of Tasks