Signal Line Groups - IBM 1 Series Manual

Signal Line Groups
Service Group Signal Lines
Poll Group Signal Lines
The I/O channel signal lines are shown, by group, in Figures 2-1 and 2-2.
Note: The direction is shown for each line with the assumption that the
I/O channel originates on the left and the I/O attachments are on the
right.
The signal lines associated with the service group are shownin Figure 2-1.
Signal
name
Address busbits 0-15
Address busbit 16
Data bus
Address gate
Address gate return
Service gate
Service gate return
Condition code in bus
Cycle input indicator
Cycle byte indicator
Status bus
Data strobe
Initiate IPL
IPL
Halt or MCHK (machine check)
System reset
Poweron reset
Total numberof lines
Figure 2-1.
The signal lines associated with the poll group are shown in Figure 2-2.
Signal
name
Request in bus
Cycle steal request in
Poll identifier
Poll
Poll prime
Poll propagate
Poll return
Burst return
Total numberof lines
Figure 2-2.
Direction
Service group signal lines
Direction
Poll group signal lines
Number
of lines
16
I
Number
of lines
Processor I/O Channel
2-3