Specifications

2 - 3
The board's I/O connectors consist of dual-row male header connectors, of varying lengths. Each
of these headers can be mated with either flat ribbon (IDC) or discretely-wired connectors. J2, J3,
J4, J5, and J6 have been placed together at one end of the board so that a single header plug can
mate with one or more of these connectors as a group.
In some applications it is preferable to plug a specialized PC board assembly onto several or all of
the I/O connectors (J2-J8). This allows you to eliminate cables, meet packaging requirements,
add EMI filtering, or in other ways customize the installation of the Little Board/286 in your
application. In addition, two dual-row male headers provide the PC and AT expansion bus for
onboard MiniModule expansion.
2.1.2 Jumper Configuration Options
For normal AT compatible operation, no special jumpering of the Little Board/286 is required.
As shipped from the factory, the board can be connected to appropriate peripherals and operated
immediately. Typically, the only jumpers you will need to be concerned with are those used for
setting the amount of onboard DRAM memory and for specifying whether the powerup video
mode is monochrome or color. Table 2-2 summarizes the board's jumper options; they are each
discussed in detail in this chapter.
Each of the board's jumper options is referred to by a "W" number (i.e. "W1"). Jumpers occur in
2-pin groups, 3-pin groups, and 6-pin groups. The pin numbering convention for all two- and
three-pin jumper groups is as follows: assuming that the card edge connectors are at the bottom
and the I/O connectors are at the right-hand side (Figure 2-1), "pin 1" is topmost on a vertically
oriented line of jumper pins, or leftmost on horizontally oriented pins.
In the case of 2-pin jumper groups, the pair of jumper pins is either shorted or unshorted by
installing or removing a shorting block. For three-pin jumper options, there are three choices:
shorting pin 1 to pin 2; shorting pin 2 to pin 3; or shorting neither.
Two jumper groups (W13 and W21) each have 6 pins. The pin numbering and settings for these
four 6-pin jumper groups are discussed later in this chapter.
Table 2-2. Configuration Jumper Summary
JUMPER GROUP FUNCTION
W1 SCSI termination power
W3,4,5 DRAM memory quantity
W7 Parallel port address option
W12,13,20,21 Byte-wide memory socket setup
W19 Dual speed floppy enable
W22 Video (mono or color)
W2,6,8-11, Factory assembly options.
14-17 (Do not alter)
2.1.3 "Soft Configuration" Options
In addition to the various configuration jumper options, there are a number of system
configuration parameters, which are initialized by the ROM-BIOS based on the contents of two
different nonvolatile memory devices on the board -- an AT compatible nonvolatile static RAM
within the real time clock device, and a unique 1024 bit configuration EEPROM).
The combination of these two devices will be referred to as the board's nonvolatile Configuration
Memory. Through the use of this Configuration Memory function, the number of jumper
configuration options has been minimized and board setup had been simplified. A configuration
utility, SETUP, is provided in the ROM-BIOS and can be accessed either with a "hot-key" entry