AR-B1476 User
’
s Guide
3-6
Name Description
-MASTER
[Input]
The MASTER is the signal from the I/O processor which
gains control as the master and should be held low for a
maximum of 15 microseconds or system memory may be
lost due to the lack of refresh
-MEMCS16
[Input, Open collector]
The Memory Chip Select 16 indicates that the present data
transfer is a 1-wait state, 16-bit data memory operation
-IOCS16
[Input, Open collector]
The I/O Chip Select 16 indicates that the present data
transfer is a 1-wait state, 16-bit data I/O operation
OSC
[Output]
The Oscillator is a 14.31818 MHz signal used for the color
graphic card
-ZWS
[Input, Open collector]
The Zero Wait State indicates to the microprocessor that
the present bus cycle can be completed without inserting
additional wait cycle
Table 3-4 I/O Channel Signal’s Description
3.2.5 LED Header
(1) External Power LED & Keyboard Lock Header (J6)
1 Power LED+
2 No Used
3 Power LED-
5 Key-Lock-
4 Key-Lock+
Figure 3-9 J6: Power LED & Keyboard Lock Header
(2) HDD LED Header (J3)
1 LED+
2 LED-
1
2
Figure 3-10 J3: HDD LED Header
(3) Watchdog LED Header (J1)
1
2
LED+
LED-
Figure 3-11 J1: Watchdog LED Header
