CSI - Interpret command parameters.

Syntax:

CALL 401DH

Input:

HL = starting address of a file name enclosed in double quotes. This must end with X’00’ or ‘:’.

Exit:

The file name was checked and transferred to the FNAM field of the DOS vectors.

HL = address of terminator

Registers used:

AF, B. HL

Error handling:

If the file name is not enclosed in quotation marks or not correctly terminated, this routine branches to BASIC and the message ?SYNTAX ERROR is displayed.

The first eight characters of a filename enclosed in quotation marks are transferred to the FNAM field of the DOS vectors.

A BASIC line end identifier X’00’ or a command separator ‘:’ must be located after the closing quotation mark.

This routine is used by DOS-BASIC to check the syntax.

Disk access does not take place.

Example:

...
  LD HL,DNAM1       ; address of filename
  CALL 401DH        ; are transmitted to FNAM
...
DNAM1: DEFM '"MAILBOX":'

The file name “MAILBOX” is transferred to the DOS vector FNAM for subsequent addressing.