Debugging underway for the 3174 substitute TEST mode feature

TEST REQUEST KEY ON 3270 TERMINALS AND ROLE OF THE TERMINAL CONTROLLER

The terminal controller which supports multiple 3270 style terminals has a built in capability to display status and run tests. These functions are invoked by pressing TEST to request the terminal be connected to the testing function in the controller, rather than the mainframe system software. 

The bottom line on the terminal, the Operator Information Area or status line, will display TEST when the request is satisfied and the terminal is talking to the controller's test software. Pressing the RESET key will disconnect the terminal from testing and resume normal connectivity to the mainframe. 

Tests can be requested using a terse command line, entered on the screen and terminated by the ENTER key. To run test 0, for example, the operator will type /0 and hit ENTER. Some test categories have multiple subtests, thus they would be selected by an entry like /2,3 from the operator. 

In some cases, a test will display status about a specific bit of hardware such as a terminal port or hardware section (hardware group) inside the controller. For those, the parameters are added to the end of the command line. For example, to do basic terminal check operations for the terminal on port 4, the command line /0,04 is entered. 

The 3174 controller provides 15 major test types, many with subtests, and in addition provides a menu based interface instead of, or in addition to, the command line. Hitting PA2 or PF12 at any time while in TEST mode will bring up the main menu. PF3 is an alternative to hitting RESET, ending the testing. The operator can enter single digits at a menu to select the menu choice they wish. They can also enter the subtest (and even parameters) to avoid having to move through the subtest menus - e.g. selecting 5,3 in the main menu goes directly to subtest 3 of test 5. 

DEBUGGING MY IMPLEMENTATION

Working with Andrew Kay's oec and hardware, a 3174 replacement, I coded up a partial implementation of the TEST functionality. Certain tests or status displays are directly tied to the IBM 3174 implementation, such as displaying control blocks, which have no analog in oec. Some error logs such as communications line retries or port errors will always be zero with the oec implementation, so they are either displayed with static values or not implemented. 

This is invoked by holding down ALT and hitting the key which generates TEST. The screen clears and the terminal shows TEST in the status line. Hitting PA2 or PF12 throws up the main menu. From here I can start various tests either with selection values or the alternate command line format. 

Main menu of TEST mode

I have work to complete - the terminal shows system busy state, erroneously, and the cursor is not positioned properly for the selection digits. I will continue to work through the code to finish this up over the course of the next few days.