I think this was covered in either the 'Mark V Users Guide,' GEH-5979, or the 'Mark V Maintenance Manual,' GEH-5980, or maybe the 'Mark V Application Manual,' GEH-6195, but just in case it isn't (or you don't have the manuals)....
I believe one has to have the Maintenance, Service or Supplier Password level enabled. And, then go to any Main Menu page (there is usually two, sometimes three pages of the Main Menu (it has to say 'Main Menu' at the center of the top of the display), and in the lower left-most corner of the display it should say "EXIT ALT+X". If you click on that target with the mouse (left-click), or press ALT and X keys simultaneously, the screen should switch to a command line prompt (usually in F:\USER, if I recall correctly).
The next question is: How to switch back to the IDOS display? (See how that works?) I believe you have to type EXIT (or exit) and press ENTER and the screen will switch back to the IDOS Main Menu.
Wow--I had to clear some cobwebs for that one! I don't have access to the manuals listed above at this writing, so I may not be exactly correct (sorry if I'm not--but it's been a long, Long, LONG time since I've worked on an <I>!).
Please write back to let us know how you fare with this! I think I have some notes somewhere in the back of a closet I could look up if this isn't correct.
(By the way, the targets (or the "buttons") along the bottom of any IDOS display correspond to the first eight function keys on most keyboards (F1 through F8), so pressing the corresponding function key is the same as clicking on the target.)
How to switch from GE Mark V, IDOS control screen to command DOS prompt? I agree with CSA,
The answer is covered in the
Mark V USER Manual, GEH-5979D,
and on the
Mark V Maintenance Manual, GEH-5980, page 34
Do not type CTRL+ALT+DEL, this will reboot the HMI.
(Re-starting or "rebooting the <I> can be accomplished by pressing and holding down the CTRL+ALT+DEL).
Exit to DOS Command Line only for Maintenance/Supplier/Service level.
Access to the DOS command line is allowed when the Current status of the Maintenance password level (or above) is enabled. When the Maintenance password level is enabled, a grey target will appear at the lower left-hand corner of the Main Menu screen. When this target is visible, pressing ALT + X will exit the user to the DOS command line.
(Clicking on the dark grey rectangle will not permit access to the DOS command line.)
On the Main Menu Display page 1 (there is usually 3), in the lower left-most corner of the display, click on "EXIT ALT+X" target.
Then type ExitIDOS.
How to switch back to the IDOS display?
It is necessary to exit the IDOS operating system to perform any back-up. To exit IDOS, type IDOSEXIT at the DOS prompt. Once the back-up is complete, type RUN_IDP to return to the IDOS system or turn off the <I> momentarily).