Tandy 600 Programmer's Reference Manual page 60

FUNCTION
D3h
-
Return
File
Size
AX
BX
CX
DX
SP:
BP:
SI:
Dl:
IP:
FLG
CS
DS
SS
ES
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Entry:
AH = D3h
(function
code)
BX
=
File
handle
Exit:
AX =
status
code
CX:DX
=
File
size
in
bytes
Function
D3h
returns the exact
number
of bytes
occupied by
the
specified
file.
The
file
handle
of
a
previously
opened
file
is
passed
to
HH
O/S
in
register
BX.
If
the operation succeeds, the
number
of
bytes
in
the
file is
returned
in
CX:DX,
with
the
most
significant
word
in
CX.
If
the operation
is
not successful, the carry
flag
will
be
set
on
return,
and
AX
will
contain the
status
code
indicating
the
cause
of
the
failure.
Error
Returns:
5
6
-
Access
denied;
The
specifed
handle
did not refer to
a
file.
-
Invalid
file
handle;
The
specified
handle
is
not currently
assigned.
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