CHAPTER 6

COMMANDS AND STATEMENTS

ATTRIB

The ATTRIB command changes certain specified attributes of BASIC-80 disk files. You can protect any file from writing or deleting or renaming by enabling the 'write protect' attribute, and you can later disable this attribute to alter or delete the specified file. The formats for these two operations are given below.

You can also enable or disable other file attributes with the ATTRIB command. Refer to the ISIS-II User's Guide, File Control Commands, for information on using ATTRIB with system, format, and invisible attributes.

To protect a file from writing, deletion, and renaming:

ATTRIB ":Fdrive number:filename", "W1"

To write to, delete, or rename a previously protected file:

ATTRIB ":Fdrive number:filename", "WO"

AUTO

The AUTO command automatically generates a line number at the beginning of each line when you are entering a program. The first operand specifies the number of the first line entered after the AUTO command; the second, which is optional, specifies the increment. Both operands default to 10.

AUTO [first lineJ[, increment]

To number lines starting with 10 in increments of 10:

AUTO

To number lines with an increment of 50 starting with line 300:

AUTO 300,50

If AUTO generates a line number that already exists in the program, the generated number is followed by an asterisk. To erase the existing line, enter CR; to leave that line in the program, enter Control-C to stop the AUTO process.

CLEAR

The CLEAR command sets all variables, arrays, and function definitions to zero, and closes files. If variables are referenced after a CLEAR, numeric variables will be zero and string variables will be null. The first expression is specified as an argu- ment, and the value of this expression becomes the string space, in bytes.

CLEAR [expression[,address]]

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Intel 9800758-02 manual Attrib Fdrive numberfilename, W1, Attrib Fdrive numberfilename, WO, Auto first lineJ, increment