Atari 400 Technical Reference Manual page 118

+---------+
+---------+
user
: program 1---------------------------+
+---------+ 1
f
t
IOCB/
s
:*********:
+---------+
+---------+
ZIOCB
+---------+
*
*
+---------+
CIa
: utility
1
+---------+
+---------+
I Device
Table
+---------+
+---------+
DCB :*******1
+---------+
*
*
*
+---------+
*
IDisk Filel
*
+----:
Manager
:-----+
+---------+
+------------+------+------+--+--.... ---+
+---------+
+---------+
+---------+ +---------+ +---------+
: ... : Keyboard: Disk : Printer: : Cassette:
: Ha n dIe
r
I : Ha n die
r :
: Ha n dIe
r: :
Ha n die
r: :
Ha n dIe
l' :
+---------+ +---------+
+---------+
+---------+
+---------+
+------------+------+------+-----.... ----------------+
+---------+
DCB :*********:
+---------+
+---------+
SIO
: Utility :
+---------+
Where: shows a control path.
**** shows the data structure re~uired for a path.
Note the following:
1.
The Keyboard/Display/Screen Editor handlers don/t use
SIO.
2. The Diskette Handler cannot be called directly from
CIa.
3. The DCB is shown twice in the diagram.
Figure 9-1 I/O Subsystem Flow Diagram
OPERATING SYSTEM
C016555 --
Section 9
133