Specifications
Note
1be
768K option also requires that the
video
mode jump-
ers
be
set to the EGA/VGA option;
i.e.
jumpers-Wl~~
W31
must
be.!U).
Table 2-4 provides the jumper information for the eight possible onboard DRAM memory
configurations.
Table 2-4
Onboard
DRAM
Memory
Size
Jumpering
AMOONT
SI1II1
SI1II2
SIMM3
W42 W43
W44
OK
no
no no
open open
open
64K
yes
no
no
short
open
open
1281(
yes
no
no
open
short
open
256K
yes
no
no
short
short
open
512K
yes yes
no
open
open
short
640K
yes
yes yes short
open
short
704K(*)
yes yes
yes
open
short
short
7681(**)
yes yes yes short short
short
Default: ei ther
256K,
512K,
or
640K,
depending
on
whether
1, 2, or 3
SIMM
DRAM
modules
are
installed.
(*)
NOTE:
Do
not use with
EGA/VGA
video
controller.
(**)
NOTE:
7681(
option
also
requires the
EGA/VGA
video
mode, i
.e.
j~rs
1119
and
1131
RlJSt
be on.
Also,
no
video
controller
can be present.
2.3.2
Math
Coprocessor
(J10)
The Little Board/PC does not support the use of a math coprocessor. The connector at
no
was
originally intended for direct connection
to
an
NEC uPD72191.
but
this device was
canc~led
by NEC.
Caution
Do
not
connect
an
8087
at
no.
as
damage
to
both
the
board and the Ie may result.
Jumper
option.l£JQ. corresponds to "switch
2"
of a standard PC motherboard. and indicates
whether
an
8087 math coprocessor
is
present in the system.
This
jumper is shorted by a trace
on
the board. which indicates that a coprocessor
is
not present.
2-6