IBM Series 1 User Manual page 20

c
c
c
The I/O Channel signal lines can be subsetted depending upon
the level of fU,nction reguired by the I/O att.achment. In
order of increasing level of function, these subsets are:
• Basic subset
• Interrupt subset
• Cycle Steal/IPL subset
Attachment to a subset is a prerequisite for attachment
to the next higher level subset.
The basic subset consists of the busses and tags to support
functions initiated by the processor; that
is,
DPC (direct
program control) commands. This includes the data transfers
associated with the ope command itselt.
The basic subset
supports
DPC
devices that do not interrupt.
The I/O signal lines in the basic subset are listed in
Figure 2-3.
Figure 2-3 (Part 1 of 2).
~asi£ Subset--Ser.!i~
GrQ'!!£
~~gn~l 1in~
Address bus bit
Address bus bit
Data
bus
*2
Address gate
00-15 *1
16
Address gate return
Condition code in bus
Da
ta strobe
Halt or MCHK
System reset
Power on reset
------)
_._----)
------>
------>
<------
<------
------)
------>
------>
------>
16
1
18
1
1
]
1
1
1
1
Processor I/O Channel 2-5