ERASE - Delete disk files

    ERASE "filespec" [,Ddrive] [<ON|,>Udevice] [,R]

This command is identical to DELETE and SCRATCH. See the SCRATCH command for details.

    ERASE "myfile"          Deletes the file MYFILE on the system drive.

ERR$ - Error message function

    ERR$ (error_number)

This function returns a string which is the BASIC error message corresponding to the given error message. If the given number is too small (less than 1) or too large (greater than 41) an 'ILLEGAL QUANTITY' error is reported.

This function is usually used to display a BASIC error condition in a TRAP routine, using the BASIC error word ER as the error number. Note that when ER=-1, no BASIC error has occurred and ER$(-1) results in an illegal quantity error.

See the example at TRAP.

EXIT - See DO/LOOP/WHILE/UNTIL/EXIT

EXP - Function to return e^x

    EXP (number)

This function returns the numeric value of e (2.71828183), the base of natural logarithms) raised to the power of given number. If the number is greater than 88.0296919 an 'OVERFLOW' error is reported.

        X = EXP(4)          Result is X=54.5981501

FAST - Set system speed to 3.58MHz

FAST is the default state of the system. FAST is used to restore this state following direct access of "slow" 1/0 devices such as the. SID sound chips.

FETCH - (see the DMA command)

FILTER - Define sound filter parameters

    FILTER [freq] [,[lp] [,[bp] [,[hp] [,res] ]]]
    
    freq ...... Filter cut-off frequency (0-2047)
    lp ........ Low pass filter on (1), off (0)
    bp ........ Band pass filter on (1), off(0)
    hp ........ High pass filter on (1), off(0)
    res ....... Resonance (0-15)

[*** THIS COMMAND IS SUBJECT TO CHANGE ***]

Unspecified parameters result in no change to the current value. The filter output modes are additive. For example, both low pass and high pass filters can be selected to produce a notch (or band reject filter response. For the filter to have an audible effect at least one filter output mode must be selected and at least one voice must be routed through the filter.