Page 9
Manual 41417-159-2
Chapter 3: Operation
The EMC-FDM provides a 3.5" floppy disk drive and controller and both a standard 25-pin
parallel port and a 9-pin DTE serial port. Both ports are implemented using a single VLSI
VL16C452 chip. The VL16C452 provides two serial channels, channel 0 and channel 1. Channel
0 is not used.
This chip does not support HDLC and SDLC protocols. For detailed programming informa-
tion, see the appropriate VLSI Technology data manual.
The floppy disk is controlled by a 37C65C floppy disk controller, identical to other Industrial
Computer Source products.
The floppy drive supports both 1.44 Mbyte and 720 Kbyte 3.5" diskettes. The drive select is set
as the A: drive.
Connectors
The parallel printer port is a standard female DB-25 with the pin-out defined as follows:
Pin
Signal
Pin
Signal
1
Strobe
14
Auto Line Feed
2
D0
15
Error
3
D1
16
Initialize Printer
4
D2
17
Select In
5
D3
18
Signal Ground
6
D4
19
Signal Ground
7
D5
20
Signal Ground
8
D6
21
Signal Ground
9
D7
22
Signal Ground
10
Acknowledge
23
Signal Ground
11
Busy
24
Signal Ground
12
Paper End
25
Signal Ground
13
Select
1
14
25
13
Table 4: DB-25 parallel port pinout.
