Re: Re: GCIC Fullscreen applications

On 8/25/2010 7:29 PM, Rocky wrote:
>
> Just one caveat - Needs to run in BC mode so in MAINT you may have to do
> a set ecmode off first.
> then I CMS.

Nah.. I don't think so.

You can run with a BC mode PSW with on an ECMODE ON virtual machine (but 
not the other way around).

The only reason for SET ECMODE OFF to exist is to allow CP to perform 
fast virtual machine context switching - since there is a whole lot less 
to save when the machine is guaranteed not to be able to do ECMODE stuff.

With ECMODE OFF :
- No (virtual) EC mode PSW (of course, the real PSW is an EC mode PSW - 
always).
- No Clock Comparator or CPU Timer
- No STOSM or STNSM instructions
- Only 1 CR : CR0
- And some other things I can't remember off the top of my head..

With ECMODE ON, none of the above restrictions exist : you have a 
(almost) complete S/370.

--Ivan