Technical information

7/4 LS PRO OWNER'S HANDBOOK
Using PCMCIA Cards
Chapter 7
Configuring PCMCIA cards
The following table describes the system resources commonly
required by a PCMCIA PC Card.
Resource Description
Memory windows A memory window is a specified range
of addresses within system memory,
through which the PC Card’s memory
can be addressed. A card typically
requires no more than one or two
memory windows for use by its client
software. Memory windows are
typically located in the computer’s
upper memory area between addresses
C8000h and DFFFFh.
I/O windows An input/output (I/O) window
specifies a range of I/O ports used to
control the operation of the card. A
card may have at most two I/O
windows. Each I/O port is an address
low down in the processor’s address
space, usually between 100h and 3FFh.
Interrupt The interrupt request level or IRQ (the two
terms are used interchangeably) is the
line over which a PCMCIA card sends a
signal to get the attention of, or interrupt,
the processor. Three interrupts, IRQ9,
IRQ10 and IRQ15, are already assigned
for PCMCIA; IRQ3, IRQ4, IRQ7 and
IRQ14 can also be used if required
(although IRQ14 can only be used on
systems without a hard disk).
In addition, Card & Socket Services itself requires an interrupt
(used to detect card insertion and removal) and four kilobytes
of upper memory (used to access the cards’ configuration
information). The preferred solution is to use IRQ10 and
C8000h-C9000h.