Memory expansion port

This port (sometimes called the RS-232 or modem port) was designed with the experimenter in mind. Just as the memory expansion port gives you access to a number of the microprocessor s control lines, this port gives you access to many of the control lines of one of the interface adapter chips. Using these lines, a wide variety of peripherals could be connected, since both serial and eight-bit parallel communications are available. 

System Interconnect Expandability From the standpoint of expansion limitations, the shared memory system has problems in that the number of ports are fixed. Expanders can be used to alleviate this problem to some degree, but physical construction problems are ultimately met. Also, the memory bandwidth of the shared memory system is fixed and is relatively slow, thus limiting the degree of practical expansion. 

Expansion slots Memory slots Processor slots or sockets Power connectors On-board disk drive connectors Keyboard connector Peripheral port connectors BIOS chip CMOS battery Jumpers and DIP switches... 

The same procedures that are used to configure the 8-bit expansion cards are used to configure ISA cards. You need to configure the card for interrupts, memory addresses, DMA channels, and I/O ports. Again, this is done using jumpers and DIP switches. 

As we have already mentioned, one of MCA s strengths is that you can use software to configure it. Installing an expansion card in an MCA slot still involves the same concepts as installing an ISA card. You must configure the card to use an available IRQ, DMA channel, memory address, and FO ports. To configure the options on these cards, you must use a Reference disk and an option diskette after installing the device into the computer physically. 

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