not use a pathname. After the parsing rules have been set up, the carry flag is cleared
("no error"), and an RTS returns control to BASIC.SYSTEM.

BASIC.SYSTEM then parses the command line according to the instructions in
PBITS, updates FBITS ($BE56) and FBITS + 1 ($BE57) to indicate the results of the
parse, and then jumps to EXECUTE. (Its address was previously stored in XTRNADDR.)

EXECUTE examines FBITS to see if a specific slot and drive were specified. If so,
the slot and drive specified are retrieved from VSLOT ($BE61) and VDRIV ($BEfi2)
and used to form the unit number required by the ON LINE command. If not, the
unit number is set to 0; this indicates to the M LI that all volumes are to be examined.

Once the ON - LINE command has been executed, the names of the active
volumes are stored in the buffer beginning at HIMEM. (See the discussion of
ON LINE in Chapter 4 for a description of the structure of this buffer.) The volume
names are then extracted from the buffer and displayed in the following format:

SLOT 6, DRIVE 1: TEST.V0LUME

Adding Comniands to BASIC. SYSTEM 263