System Specification for C65 Fred Bowen March 1, 1991

### 3.1.3BASIC 10.0 COMMAND AND FUNCTION DESCRIPTION

#### ABS - Absolute value function

```                              ABS (expression)
```

The ABSolute value function returns the unsigned value of the numeric expression.

```                    X = ABS (1)             Result is X = 1
X = ABS (-1)            Result is X = 1
```

#### AND - Boolean operator

```                         expression AND expression
```

The AND operator returns a numeric value equal to the logical AND of two numeric expressions, operating on the binary value of signed 16-bit integers in the range (-32768 to 32767). Numbers outside this range result in an 'ILLEGAL QUANTITY' error.

```                    X = 4 AND 12            Result is X=4
X = 8 AND 12            Result is X=8
X = 2 AND 12            Result is X=0
```

In the case of logical comparisons, the numeric value of a true . situation is -1 (equivalent to 65535 or \$FFFF hex) and the numeric value of a false situation is zero.

```      X = ("ABC"="ABC") AND ("DEF"="DEF")   Result is X=-l (true)
X = ("ABC"="ABC") AND ("DEF"="XYZ")   Result is X= 0 (false)
```

#### APPEND - open a disk file and prepare to append data to it

```     APPEND# logical-file-number, "filename" [,Ddrive] [<ON|,>Udevice]
```

Opens filename for writing, and positions the file pointer at the end of the file. Subsequent PRINT# statements to the logical file number will cause data to be appended to the end of this file. If the file does not exist, it will be created.

```            APPEND#1, "filename"
APPEND#1, (file\$), ON U(unit)
```

#### ASC - PETSCII value function

```                                ASC (string)
```

This function returns the PETSCII numeric value of the first character of a string. The PETSCII value of an empty (null) string is zero. This function is the opposite of the CHR\$ function. Refer to the Table of PETSCII Character Codes.

```                    X = ASC("ABC")          Result is X=65
X = ASC("")             Result is X=0
```

#### ATN - Arc tangent function

```                              ATN (expression)
```

 This page has been created by Sami Rautiainen. Read the small print. Last updated April 09, 2006.