Intel 9800758-02 manual Dir, Edit, End, Error

Commands and Statements BASIC-SO

DIR

The DIR command displays the names, number of blocks, and length (in bytes) of the files saved on the specified disk. If no drive number is specified, the default is drive O. DIR may be used as a command or as a statement.

DIR [drive number]

EDIT

The EDIT command is used to modify single program lines. In this mode, you have a selection of editing subcommands that facilitate character insertion, deletion and changing. These subcommands and their uses are explained in Chapter 3: Entering and Editing BASIC-80.

The EDIT mode is entered automatically when a syntax error prevents program execution. It can also be entered when.entering text by typing Control A, or it may be entered by typing EDIT line number. Refer to Chapter 3: Entering and Editing BASIC-80.

EDIT line numbeq .

The period (.) is used to represent the last line changed, listed or that contained an error.

END

The END statement halts program execution and returns to BASIC-80 command level. Files are closed, but variables can be examined. END may be used at any logical conclusion point within program text. STOP acts like END, but also prints a "BREAK IN line number" message, and does not close files. An END command is optional as the last line of a program.

END

The program below contains an END statement in line 40.

10INPUT A,B,C

20D=(A + B + C)/3

30PRINT "THE AVERAGE OF";A;" + ";8;" + ";C;"EQUALS";D;"."

40END

ERROR

The ERROR statement simulates the occurrence. of an error in program execution. The user-supplied integer expression will generate an error message appropriate to its value, as shown in the example listed below. The integer expression supplied must be greater than 0 and less than or equal to 255. If ERROR is executed with a number that does not correspond to a BASIC error message, "UNPRINTABLE ERROR" will print. All errors can be trapped by the ON ERROR statement. For further in- formation, refer to Chapter 4: Error Handling.

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