Little Board™/486e Technical Manual
2–66Table 2–46. AT Expansion Bus Connector, A1-A32 (P1)
Pin Signal
Name Function In/Out Current PU/PD/S *
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
A16
A17
A18
A19
A20
A21
A22
A23
A24
A25
A26
A27
A28
A29
A30
A31
A32
IOCHCK*
SD7
SD6
SD5
SD4
SD3
SD2
SD1
SD0
IOCHRDY
AEN
SA19
SA18
SA17
SA16
SA15
SA14
SA13
SA12
SA11
SA10
SA9
SA8
SA7
SA6
SA5
SA4
SA3
SA2
SA1
SA0
GND
bus NMI input
Data bit 7
Data bit 6
Data bit 5
Data bit 4
Data bit 3
Data bit 2
Data bit 1
Data bit 0
Processor Ready Ctrl
Address Enable
Address bit 19
Address bit 18
Address bit 17
Address bit 16
Address bit 15
Address bit 14
Address bit 13
Address bit 12
Address bit 11
Address bit 10
Address bit 9
Address bit 8
Address bit 7
Address bit 6
Address bit 5
Address bit 4
Address bit 3
Address bit 2
Address bit 1
Address bit 0
Ground
IN
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
IN
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
N/A
N/A
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
N/A
4 mA
12 mA
12 mA
12 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
4 mA
N/A
4.7K PU
4.7K PU
4.7K PU
4.7K PU
4.7K PU
4.7K PU
4.7K PU
4.7K PU
1K PU
* PU = pull up; PD = pull down; S = resistanc e i n seri es. All v alues in ohm s.