Chapter 2 Installation 17
Floppy drive connector (CN2)
You can attach up to two floppy disks to the SBC-411/411E/486's
onboard controller. You can use any combination of 5.25" (360 KB
and 1.2 MB) and/or 3.5" (720 KB, 1.44 MB, and 2.88 MB) drives.
The CPU card comes with a 34-pin daisy-chain drive connector
cable. On one end of the cable is a 34-pin flat-cable connector.
There are two sets of floppy disk drive connectors, one in the
middle, and one on the other end. Each set consists of a 34-pin flat-
cable connector (usually used for 3.5" drives) and a printed-circuit
board connector (usually used for 5.25" drives).
Connecting the floppy drive
1. Plug the 34-pin flat-cable connector into CN2 on the CPU card.
2. Attach the appropriate connector on the other end of the cable
to the floppy drive(s). You can use only one connector in the
set. The set on the end (after the twist in the cable) connects to
the A: floppy. The set in the middle connects to the B: floppy.
Pin assignments
The following table lists the pin numbers and their respective
signals:
Floppy disk connector (CN2)
Pin
Signal
Pin
Signal
1~33(odd)GND
2
High density
4, 6
Unused
8
Index
10
Motor enable A
12
Driver select B
14
Driver select A
16
Motor enable B
18
Direction
20
Step pulse
22
Write data
24
Write enable
26
Track 0
28
Write protect
30
Read data
32
Select head
34
Disk change
StockCheck.com
