Table of Contents
Advertisement
Section A:
System interface
************************************************************************
*
*
*
15 - Open File
*
*
*
*************************************************~**********************
On entry:
c
@FH
DE
address of FCB
On return:
A
H
error code
physical error code
Possible logical errors:
- none -
Possible physical errors:
@ -
no errors occurred
l - Read/write error
4
Drive not selectable
9
Question marks in file name
Differences to CP/M plus:
1) A password will be ignored.
Differences to CP/M 2.2 resp. DiCOS:
1) Automatic
search in user area 0 und opening for reading
if
present
there.
2) The file name must be unambiguous.
3) A byte count will be taken over.
The
file
specified by DE is opened.
Opening a file is
essentially
a
directory search (on the selected drive} for the file name,
followed by
copying
the information found there into the FCB.
The high extent byte
is always set to zero.
Normally,
the lower extent byte is also set
to
zero,
however,
it
is possible to specify an extent number in order to
open a specific extent.
The file name must be unambiguous, i.e. it must
not contain question marks.
The Current Record Byte within the FCB (byte number 32) should be set to
zero to enable subsequent sequential access.
If it is set
to 0FFH, the
byte count (see function 31) is copied into this byte.
EOS System manual
Daeumling & Zimmermann
Page 46
Advertisement
Chapters
Table of Contents
