Epson PX-8 Technical Manual page 17

REV.-A
49 31
1:-=------------=--::1
Table 1-13 eN8 (Expansion) Interface
50 42
Pin Signal
Direction Definition
No. Name
Pin Signal
Direction Definition
No. Name
1 AB12 0 Address bus 1 2 2 AB11 0 Address bus 11
3 AB14 0 Address bus 14 4 AB13 0 Address bus 1 3
5 AB 1 0 Address bus 1 6 AB 2 0 Address bus 2
7 AB15 0 Address bus 15
8
AB 0
0
Address bus 0
9 AB 4
0
Address bus 4 10 AB 3
0
Address bus 3
11 AB 6 0
Address bus ~l
12 AB 5
0
Address bus 5
13 AB10
0 Address bus 10 14 AB 7 0 Address bus 7
15 AB 8
0 Address bus 8 16 AB 9 0 Address bus 9
17
DB 0 I/O Data bus 0 18 DB 1
I/O
Data bus 1
19 DB 2
I/O Data bus 2 20 DB 3 I/O Data bus 3
21 DB 4 I/O Data bus 4 22 DB 5
I/O
Data bus 5
23 DB 6
I/O
Dat bus 6 24 DB 7
I/O
Data bus 7
- -
25 BURQ 0 Bus request 26 BUAK
0
Bus acknowledge
27 M1 0 Machine cycle 1 28 WAIT I Wait
29 Vl 0 Circuit voltage: +5V 30 HlTA 0 Halt acknowledge
31 GND
-
Signal ground 32 GND
-
Signal ground
33
RS
0
Reset
34 SPI I Speaker
-
35
RD
0 Read 36
MRQ
0
Memory request
-
37 WR 0 Write 38 ClK 0 2.45 MHz
39 VCH 0 Charging voltage 40 10RQ 0 I/O request
41 DCAS 0 Data CAS 42 DW 0 Data write
43 INTEX I External interruption 44 OFF
0
Initializilng signal of IC "6A"
- -
- -
45 RXD I Serial received data 46 TXD 0 Serial send data
- -
47 VB1
0 Battery voltage 48 BK2 I Bank exchange
49
CG
-
Chassis ground 50 CG
-
Chassis ground
1-13