Specifications

Hardware Configuration
2–4
Connectors
The I/O connectors are shrouded dual-row headers for use with flat ribbon (IDC) connectors and
ribbon cable. Ampro recommends that you use “center-bump polarized” connectors to prevent
accidentally installing cables backwards. Use non-strain-relief connectors to stay within the vertical
height envelope shown in Figure 1–1.
Many of the connectors have “key pins”. Install a blocking key in the corresponding connector socket
on the mating ribbon cable to prevent misalignment.
You can install a retaining clip to secure the cable to its connector. This is especially useful in high-
vibration environments. You can also design a PC board assembly, made with female connectors in
the same relative positions as the Little Board’s connectors, to eliminate cables, meet packaging
requirements, add EMI filtering, or customize your installation in other ways.
The PC/104-compatible expansion bus appears on two connectors (P1 and P2). You can expand the
system with on-board MiniModule
™
products or other PC/104-compliant expansion modules. These
modules stack directly on the connectors, or use conventional or custom expansion hardware,
including solutions available from Ampro.
If you plan to use the on-board video controller with a flat-panel LCD screen, you can install Ampro’s
optional LCD Bias Supply board on connector J4, as shown in Figure 2-1. This board can be
jumpered to supply positive or negative Vee from ±15V to ±35V (adjustable).
2.1.2 Jumper Configuration Options
Ampro installs option jumpers in default positions so that in most cases the Little Board/486i requires
no special jumpering for standard AT operation. You can connect the power and peripherals and
operate it immediately. The only jumpers of concern are those that configure the byte-wide sockets
for the devices you install.
Jumper-pin arrays are designated W1, W2, and so forth. Jumper pins are spaced 2 mm apart. A square
solder pad identifies pin 1 of each jumper array. Table 2-2 is a summary of jumper use. In the
Default column, two numbers separated by a slash (for example, 1/2) means that the pins are shorted
with a 2 mm jumper block.