Little Board™/486e Technical Manual
2–44

Installing a Boot PROM

The Little Board/486e CPU can be configured for a boo t PRO M by inst allin g the boot PRO M in
byte-wide socket S0.

Installing a Boot PROM in Byte-Wide Socket S0

Install a LAN boot PROM in byte-wide socket S0. The boot PROM code is run at boot time as a
BIOS extension.
To install a LAN boot PROM in byte-wide socket S0, follow these guideline s:
1. Either obtain a preprogrammed boot PROM device, or program a PROM or FLASH EPROM
with the boot PROM image. Use a 128K byte dev ice, such as a 27C0 10, if pos sible.
2. Install the boot PROM device in S0.
3. In SETUP, set socket S0 for 64K bytes at D 0000h a nd se le ct S0 to be e nable d at boo t time .
Twisted Pair Interface (J7)
The twisted pair interface (10BaseT) appears on connector J7. It is a standard RJ45 telephone-type
modular connector, which is the normal connector used with standard twisted-pair cables. Table 2–
33 lists the signals and pin numbers of J7.
Table 2–33. RJ45 Twisted Pair Connector (J7)

J7 Pin Function

1 + Transm it Data
2 - Transmit Data
3 + Receive Data
4N/C
5N/C
6 - Receive Data
Twisted-Pair Installations
This section discusses the guidelines for tw is ted- pair in stal latio ns.
! Connector jack—A standard RJ45-terminated cable can be plugged directly to the female RJ45
connector on the Little Board/486e CPU.
! Connector plug—The RJ45 connector plugs attach to both ends of twisted-pair Ethernet cable
lengths. They are used to connect the Little Board/486e CPU to a hub or concentrator.
! Terminators—There are no external termination device s requ ired. Termin ation is hand led
automatically by the hub devices.
Twisted-pair Ethernet cable is 22 or 24 gauge copper wire twisted together in pairs. Ethernet
twisted-pair uses two pairs (four wires), one for transmitting and one to receive. It is available from