Technical Information 1-21
Bit 4
Keyboard/Auxiliary inhibit switch
When this bit is set, it indicates that the keyboard and auxiliary device are not inhibited.
The keyboard controller sets bit to 0 when security mode is active.
Bit 5
Auxiliary buffer full
When this bit is set, it indicates that data received from the auxiliary device is present in
the output buffer.
Bit 6
Time-out
When this is set, a time-out has occurred during transmission between the keyboard
controller and the keyboard or auxiliary device.
Bit 7
Parity error
When this bit is set, the last byte received from the keyboard or auxiliary device has an
uncorrectable parity error.
System Memory
Image P90E and Image P100E configurations ship with 16 MB of RAM. System memory
can be expanded to a maximum of 256 MB. Total address space is 4 gigabytes (GB)
maximum. Memory expansion is performed using single in-line memory modules
(SIMMs) installed in SIMM sockets on the memory expansion board.
The memory expansion board consists of eight SIMM connectors organized into four
banks. All system memory supports parity. Memory shipped with the system is comprised
of two 2-MB x 36-bit DRAM SIMM modules (which is 2 x 8MB). The first megabyte
includes the standard 640 KB of base memory. The remaining memory is extended
memory.
The SIMM memory sockets accept 4-, 8-, 16-, or 32-MB SIMM sticks. High-speed RAM
is 32 bits wide with four parity bits. SIMMs are 1 M x 36 bit (4 MB), 2 M x 36 bit (8 MB),
4 M x 36 bit (16 MB), and 8 M x 36 bit (32 MB). There are no switches or jumpers to set
when SIMMs are added.
The system board's eight SIMM sockets are assigned as banks 0, 1, 2, and 3. Each SIMM
kit is inserted into a pair of sockets or bank. Bank 0 contains the two standard SIMMs
shipped with the system. Banks 1, 2, and 3 are available for memory expansion. Different
size SIMMs cannot be intermixed within a bank. See Section 3, Options, for installation
instructions and SIMM memory configurations.