CHAPTER 21


ERROR HANDLING

This chapter describes the error handling services ER$LKUP and ER$MESS.


21.0.1 ER$LKUP

VECTOR NUMBER : 013
INPUT PARAMETERS :
     B = error number
OUTPUT VALUES :
     X = address of error message

DESCRIPTION

Given an error code in B, returns the address of the appropriate error message in X. The returned error message is a leading count byte string. If there is no error message for this error code, the default message "*** ERROR ***" is returned. ER$LKUP is called by the OPL function ERR$.

EXAMPLE

        LDA     B,ERROR_CODE    ; B = ERROR CODE 
        OS      ER$LKUP 
        LDA     B,0,X           ; GET LENGTH BYTE 
        INX                     ; SKIP PAST 
        OS      DP$PRNT         ; PRINT THE ERROR MESSAGE

ERRORS: None


21.0.1.1 ER$MESS

VECTOR NUMBER : 032
INPUT PARAMETERS :
     B = error number
OUTPUT VALUES : None

DESCRIPTION

Displays the error message associated with the error code given in B. ER$MESS then waits for the user to press SPACE or ON/CLEAR.

If there is no error message for this error code, the default message "*** ERROR ***" is displayed.

NOTE : In the case of B = 194, the machine displays the message "BATTERY TOO LOW" for 4 seconds, then switches off.

EXAMPLE

        LDA     B,ERROR_CODE 
        OS      ER$MESS

ERRORS: None