Specifications
Table
2-1.
Summary
of
Connector
Usage
SEGMENT
FUNCTION
SIZE
J1
Power
Input 4-pin
J2
(*)
V40
Serial
6-pin
J3
(*)
PC
Serial
10-pin
J4
Util
ity
10-pin
JS
Keyboard
6-pin
J6
Printer
26-pin
J7
SCSI
50-pin
J8
Floppy
34-pin
J9
PC
Bus
64-pin
J10
Math
Option 40-pin
(*)
J2
and
J3
are
combi
ned
on
a
single
16-pin connector.
2.1.2
Jumper
Options
For
normal
PC
compatible operation, no special jumpering
of
the Little
Board/PC
is re-
quired.
As
shipped from the factory, the board can
be
connected to appropriate peripherals
and operated immediately. Typically, the only jumpers
you
need
be
concerned with are the
following:
• Floppy drive quantity. See Table
2-16;
default = 2 drives.
• Floppy drive type. See Table
2-17
and
2-18;
default =
360K
drives.
• Video mode. See Table
2-21;
default = color.
• SCSI bus disable. See Section
2.5;
default = enabled.
Note
If
you do not use SCSI,
be
sure to use the disable
jumper
as
discussed
in
Section
2.5,
as
it
eliminates system boot
delay.
Each of the board's jumper options
is
referred to by a "W' number (i.e.
W1-W47).
In
nearly
every case,
the
jumper option consists of a pair of pins which
is
either shorted
or
unshorted by
installing
or
removing a shorting block. Several jumper options consist
of
three pins.
For
these jumper options, there are three choices: shorting pin 1 to pin
2;
shorting pin 2 to pin
3;
or shorting neither. One exception is
W45,
which has 6 pins
--
labeled
on
the board.
The pin numbering convention for all jumper options (except
W45)
is
as
follows:
assuming
the orientation of the Little Board/PC shown in Figure
2-1,
pin 1
is
either the one on the left
or the one
on
the top, depending on which
axis
the jumper group occupies.
2-3