PC Hardware A Beginner’s Guide

(^152) PC Hardware: A Beginner’s Guide

Installing a SIMM in a PC

Before you begin installing a SIMM module, be sure that you have the right SIMM for

your system. There aren’t a lot of choices, but the ones you have are significant to your

PC’s acceptance of the new memory:

 Match the number of pins The number of pins on the SIMM must match

that of the motherboard socket. A 72-pin module will not fit into a 30-pin

socket. However, using a SIMM converter add-in board, 30-pin modules

can be adapted into a 72-pin socket.

 Parity versus nonparity Verify whether your system uses parity or nonparity

memory and avoid mixing and matching. A nonparity system will take a

parity memory module and simply ignore the parity bits, but it is always better

to match like components together. A parity system will take ECC memory.

 Match the metal Avoid mixing gold connectors with tin sockets and vice

versa. Doing so could lead to intermittent memory problems or a failed

memory module.

One end of a SIMM is notched, or slightly cut away, as shown in Figure 7-9. The

socket on the motherboard has a similar notch or cut on one end. Before inserting a SIMM

into the mounting socket, match u pthe notched ends. This will ensure that you have the

SIMM oriented correctly for installation.

The SIMM is placed into the mounting socket at about a 45-degree angle with the

module angled away from the back of the socket, as shown in Figure 7-10. Before setting

Figure 7-8. A SIMM in its protective and antistatic packaging