Z80 Serial In/out
NOTE: the asterisk means ACTIVE LOW
| Z 80 SIO/0 |
Pin |
Use |
Pin |
Use |
Pin |
Use |
Pin |
Use |
 |
1 |
D1 |
11 |
*SYNC A |
21 |
*RESET |
31 |
GND |
| 2 |
D3 |
12 |
RxDA |
22 |
*DCDB |
32 |
*RD |
| 3 |
D5 |
13 |
*RxCA |
23 |
*CTSB |
33 |
C/*D |
| 4 |
D7 |
14 |
*TxCA |
24 |
*RTSB |
34 |
B/*A |
| 5 |
*INT |
15 |
TxDA |
25 |
*DTRB |
35 |
*CE |
| 6 |
IEI |
16 |
*DTRA |
26 |
TxDB |
36 |
*IORQ |
| 7 |
IEO |
17 |
*RTSA |
27 |
*RxTxCB |
37 |
D6 |
| 8 |
*M1 |
18 |
*CTSA |
28 |
RxDB |
38 |
D4 |
| 9 |
+ 5V |
19 |
*DCDA |
29 |
*SYNCB |
39 |
D2 |
| 10 |
*W/RDYA |
20 |
CLOCK |
30 |
*W/RDYB |
40 |
D0 |
| Z 80 SIO/1 |
Pin |
Use |
Pin |
Use |
Pin |
Use |
Pin |
Use |
 |
1 |
D1 |
11 |
*SYNC A |
21 |
*RESET |
31 |
GND |
| 2 |
D3 |
12 |
RxDA |
22 |
*DCDB |
32 |
*RD |
| 3 |
D5 |
13 |
*RxCA |
23 |
*CTSB |
33 |
C/*D |
| 4 |
D7 |
14 |
*TxCA |
24 |
*RTSB |
34 |
B/*A |
| 5 |
*INT |
15 |
TxDA |
25 |
TxDB |
35 |
*CE |
| 6 |
IEI |
16 |
*DTRA |
26 |
TxCB |
36 |
*IORQ |
| 7 |
IEO |
17 |
*RTSA |
27 |
*RxCB |
37 |
D6 |
| 8 |
*M1 |
18 |
*CTSA |
28 |
RxDB |
38 |
D4 |
| 9 |
+ 5V |
19 |
*DCDA |
29 |
*SYNCB |
39 |
D2 |
| 10 |
*W/RDYA |
20 |
CLOCK |
30 |
*W/RDYB |
40 |
D0 |
| Z 80 SIO/2 |
Pin |
Use |
Pin |
Use |
Pin |
Use |
Pin |
Use |
 |
1 |
D1 |
11 |
*SYNC A |
21 |
*RESET |
31 |
GND |
| 2 |
D3 |
12 |
RxDA |
22 |
*DCDB |
32 |
*RD |
| 3 |
D5 |
13 |
*RxCA |
23 |
*CTSB |
33 |
C/*D |
| 4 |
D7 |
14 |
*TxCA |
24 |
*RTSB |
34 |
B/*A |
| 5 |
*INT |
15 |
TxDA |
25 |
*DTRB |
35 |
*CE |
| 6 |
IEI |
16 |
*DTRA |
26 |
TxDB |
36 |
*IORQ |
| 7 |
IEO |
17 |
*RTSA |
27 |
*TxCB |
37 |
D6 |
| 8 |
*M1 |
18 |
*CTSA |
28 |
*RxCB |
38 |
D4 |
| 9 |
+ 5V |
19 |
*DCDA |
29 |
RxDB |
39 |
D2 |
| 10 |
*W/RDYA |
20 |
CLOCK |
30 |
*W/RDYB |
40 |
D0 |
Docs about how to program this device.