Mainframe, MVS and zOS Discussion

Hi,

Is the concept of Emulator and simulator in mainframe same? If I say I am using a simulator to connect to mainframes or if I say I am using an emulator to connect to mainframes, do they carry same or similar meaning? I have seen many people using them interchangeably..

In my mind the two terms are NOT interchangeable.  The term "emulator" is most commonly associated with 3270 terminal access to a mainframe, where the Windows / Unix software is emulating a 3270 terminal and hence 3270 data streams are going from / to the mainframe and the Windows / Unix software interprets the 3270 data stream for the GUI.  The term "simulator" is associated with Hercules-390, which simulates a mainframe through software on a PC or Unix machine.  Given an operating system, a Hercules-390 machine acts very closely to the same as a mainframe (although there are differences).

The term "simulator" is associated with Hercules-390, which simulates a mainframe through software on a PC or Unix machine. Given an operating system, a Hercules-390 machine acts very closely to the same as a mainframe (although there are differences).

I do not know who made the association, but Hercules is an emulator ..
http://www.hercules-390.org

An emulation is a system that behaves exactly like something else, and adheres
to all of the rules of the system being emulated.

It is effectively a complete replication of another system, right down to being
binary compatible with the emulated system's inputs and outputs, but operating
in a different environment to the environment of the original emulated system.
The rules are fixed, and cannot be changed, or the system fails.

if You log-in to TSO on a <OS> running under Hercules what You see and get is EXACTLY what You would see and get
if You had logged-in to TSO on a <OS> running on a real mainframe

If I say I am using a simulator to connect to mainframes or if I say I am using an emulator to connect to mainframes, do they carry same or similar meaning? I have seen many people using them interchangeably..

We call Tn3270 as emulator and I think that correct way of saying is "I am using an emulator to connect to mainframes".

enrico-sorichetti wrote:

The term "simulator" is associated with Hercules-390, which simulates a mainframe through software on a PC or Unix machine.  Given an operating system, a Hercules-390 machine acts very closely to the same as a mainframe (although there are differences).

I do not know who made the association, but Hercules is an emulator ..
http://www.hercules-390.org

So Rumba, TN3270 etc all are emulators and not simulators?Right?