Signal Tables; Fcu - Ricoh FACSIMILE FAX77 Field Service Manual

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.

1. FCU

CN1 - SRAM
Pin Name Function
1
COM1 Ground
2 A0 Address bus
3 COM1 Ground
4 A1 Address bus
5 + 5V Power supply
6 A2
Address bus
7 5RTCCS
Real time clock mode
1: Battery
8 A3
Address bus
9 + 5VBAT Voice message and real time 5
clock backup power
10 A4 Address bus
11 5RAMWR
RAM write enable
12 A5
Address bus
13 5RAMRD
RAM read enable
14 A6
Address bus
15 D0 Data bus
16
17
18
19
20
21
V
22
0
23
24
0
25
26
5
27
28
0
29
30
31 5RAMWR RAM write enable
32 1PSCNT 128k memory backup 0: 5
33 5RAMRD RAM read enable
5
34
5
7-2
A7 Address bus
D1 Data bus
A8 Address bus
D2 Data bus
A9 Address bus
D3 Data bus
A10 Address bus
D4 Data bus
A11 Address bus
D5 Data bus
A12 Address bus
D6 Data bus
A13 Address bus
D7 Data bus
A14 Address bus
Capacitor 1: + 5V
COM1
5
5
0