Re: Intial Program Load (IPL)

[Scott Klement <midrange-l@xxxxxxxxxxxxxxxx>]

Hi John,

Others have already answered this, but I wanted to say it in my own 
words. Sorry for the duplication.

An Initial Program Load (IPL) is what you'd called "booting" on a PC.

At a deeper level, you might be asking what is "booting/IPLing"?  The 
general issue comes from the fact that computer hardware doesn't know 
how to run sophisticated and powerful programs by itself To do that, you 
need an operating system, and all hardware platforms have the capability 
of running multiple OSes...

So you have a chicken & egg problem. The OS is needed to run programs, 
but a program is needed to load the OS.

The solution is that the computer hardware comes with the ability to 
load/run a very simple program, that must be stored at a very specific 
place on a disk/tape/CD, and it's limited in capability, but has enough 
smarts to load the OS -- or, at least a part of the OS, which in turn is 
capable of loading programs, etc.  So this simple program that the 
hardware knows how to run directly is called an "initial program".

Now, on the PC they use the term "boot", which is short for 
"bootstrapping".  This is a metaphor.  A bootstrap is a small strap at 
the heel-end of a boot that you can use to pull the boot on. The 
metaphor is that this intiial program is a small program used to load 
the larger program that implements the operating system.  Thus, the term 
"bootstrapping", or "boot" for short.

IBM has never liked using "clever" terms like this. They like the terms 
they use to be descriptive of the actual process.  They prefer a name 
like "Find String with PDM (FNDSTRPDM)" over a name like "grep", for 
example...   So "bootstrap" may be clever, but many won't understand 
what it means.  Initial program load (IPL) describes exactly what's 
going on in plain English.

Ironically, the term "boot" is understood by more people than IPL, 
today. The way our world works is strange...

-SK



On 10/13/2012 9:54 AM, John Mathew wrote:
> Hi,
>
> what is the purpose of IPL(Intial Program Load). What are steps involved in IPL.
>
> thanks in advance.
>
> John