Ricoh FACSIMILE FAX77 - 7-2. Signal Tables

7-2. Signal Tables
The V column contains the approximate voltage at the pin when the power is on, and the machine is in
standby mode with the handset and line connected, no roll in the printer, and a document in the ADF to switch
on the + 24VA supply. A blank means that voltage may vary.
16 A7 Address bus
1. FCU
17
D1 Data bus
18
A8 Address bus
CN1 - SRAM
19 D2 Data bus
Pin
Name Function
V
1
COM1 Ground
0
2
A0 Address bus
3
COM1 Ground
0
4 A1 Address bus
5 + 5V
6 A2
7 5RTCCS
8 A3
9 + 5VBAT
10
A4
11 5RAMWR
12 A5
13 5RAMRD
14
A6
15
D0
Power supply
5
Address bus
Real time clock mode
0
1: Battery
Address bus
Voice message and real time 5
clock backup power
Address bus
RAM write enable
5
Address bus
RAM read enable
5
Address bus
Data bus
20 A9 Address bus
21
D3 Data bus
22 A10 Address bus
23 D4 Data bus
24 A11 Address bus
25 D5 Data bus
26 A12 Address bus
27
D6 Data bus
28 A13 Address bus
29 D7 Data bus
30
A14 Address bus
31 5RAMWR RAM write enable
5
32 1PSCNT 128k memory backup 0: 5
Capacitor 1: + 5V
33 5RAMRD RAM read enable
5
34
COM1
0
7-2