Microsoft KB Archive/75564

= How to Install a First and/or Second Floppy Disk Drive =

Article ID: 75564

Article Last Modified on 7/30/2001



This article was previously published under Q75564



SUMMARY
Following are instructions on how to install a first and/or second floppy disk drive:

 Mounting the adapter card with the floppy controller cable:

 Finding pin 1 on the floppy controller:

Before mounting the controller/adapter card, locate pin 1 on the controller's board for the data and control sockets. Use the controller's documentation to help you or look at the board to find the numbers &quot;1&quot; and/or &quot;2&quot; printed on the board. Instructions for different kinds of floppy controllers:

 Combined floppy/hard disk controller card:

If you have a combined floppy/hard disk controller card, it should mount in the next expansion socket closest to the power supply. Be sure to plug it into a 16-bit expansion socket if it is a 16-bit controller. Floppy controller separate from hard disk controller:

If you have separate floppy and hard disk controllers, mount the hard disk controller first into the socket closest to the hard disk and power supply if the length of the controller boards permits it. This will help to minimize the cabling mess, since the hard disk controller and the hard disk will be next to each other in most cases. Floppy controller built into motherboard:

In some newer machines the floppy controller may be built into the motherboard or attached to a passive backplane like for instance with Wyse 386 computers. In those cases simply find pin number 1 and check the documentation on whether or not jumpers or DIP switches have to be set in order to tell the computer how many floppy drives it is going to have. </li></ol> </li> Connecting the controller cable to the floppy controller:

Now plug the cable into the socket of the controller so that the colored edge (usually red) is adjacent to pin 1 or 2 of the socket.</li> Mounting the floppy controller card with the controller cable attached:

Now mount the floppy disk controller. Since it is usually an 8-bit device, you need to find an 8-bit slot. You can plug it into a 16-bit slot, but depending on the manufacturer of the motherboard, it may or may not work correctly.

There is a data bus control line that the expansion cards can control. This line enables the cards to identify themselves as either 8-bit or 16-bit devices; therefore, it really shouldn't matter whether the 8-bit card plugs into either an 8-bit or 16-bit expansion socket.</li> Installing the floppy drive:

On newer computers there are usually grooves in the case for plastic rails that attach to the disk drives.

5.25-inch floppy drives just need these rails attached and they are ready to be slid in.

3.5-inch drives need extenders and rails that must be used to make them fit in the 5.25-inch slot.

The drives are slid in from the front and a small bracket holds them in place.</li> Connecting the controller cable to the floppy drives:

Now mate the controller cable to the edge connectors on the disk drives. You can usually only connect them one way because there is a key guide in the socket to ensure a correct connection. Again make sure that the red edge of the cable is on the side of the edge connector labeled with a &quot;1&quot; or &quot;2&quot;.

Make sure that the floppy data/control cable goes to the floppies and not the hard disk. The floppy control cable usually has two connectors. One is mounted on the end and the other is about six inches away from it. The floppy that you connect the end connector to will become drive A. The end connector is often labeled as A and the one toward the controller B.</li> Identifying drive A and B:

When installing a second floppy disk drive, it is NOT enough to simply connect the cable to the drives. Either a jumper or a resistor pack has to be moved or removed.

 Jumpers:

Some disk drives require that a jumper be set to identify drive A and drive B. Check the documentation that came with your units to find out whether you have to set a jumper for these drives. This is especially true for 3.5-inch drives.</li> Resistor pack removal:

With some floppy drives, older ones particularly, a terminating resistor pack usually is required in the final drive in the chain. This resistor pack is usually present by default. If you are using two floppy drives, the first drive must have this resistor pack removed and you have to make sure the second (or final) drive in the chain (farthest away from the controller board) has its terminating resistor in place. On newer floppy drives a jumper may have to be moved or removed (see 6a). The instructions with most of these drives are fairly clear. Simply follow the steps recommended by the manufacturer.</li></ol> </li> Making the floppy drive known to the system:

Different procedures need to be followed depending on whether you have an XT or AT computer.

  XT computers:

For XTs that have a CMOS and therefore a Setup program that may expect the drive definition, the following information in (7b) applies.

XT computers usually require some DIP switches on the motherboard to be set in order to let the system know how many floppy drives it has.

Here are the switch settings for the IBM PC motherboard switch bank 1 (SW1): <pre class="fixed_text">          Actual Number of                      SW1              SW1 5.25-Inch Floppy Drives                ON               OFF ---         --             0                              1,7,8             1                                7,8              1             2                                  8              1,7

A 3.5-inch 720K drive B drive usually requires the DRIVER.SYS or DRIVPARM.SYS driver in the CONFIG.SYS file. For example:

device = c:\dos\driver.sys /d:2 /f:2 /h:2 /s:9 /t:80

In order to get the line in the CONFIG.SYS file right, the correct physical drive number has to be determined. Floppy drive A would be considered drive 0 (Zero) and floppy drive B is drive 1. The numbers in the table above for &quot;Actual Number of 5.25-Inch Floppy Drives&quot; has nothing to do with this numbering scheme for &quot;physical&quot; drive numbers and should be disregarded.

To add a 3.5-inch 1.44 MB (high density) floppy drive to an XT, it is usually necessary to get a special set of ROM BIOS chips (if they exist for your model) and a controller that supports the 1.44 MB drive. The same may be true for older AT computers. </li>  AT computers:

On AT (286 or higher) computers, the floppy drive TYPE (3.5-inch or 5.25-inch high or low density) needs to be identified in the computer's Setup program.

To run the Setup program, simply boot from the Setup disk (for example, IBM PS/2 Reference disk, Wyse 386 Setup disk), or if the ROM BIOS has Setup built in, consult the computer's manual on how to invoke it. Many computers prompt the user upon boot-up to press a certain key (for example, F1 or DEL) to start the Setup program.

You have to enter the floppy drive TYPE and issue the save command (the keys for these commands are usually displayed and explained on the screen or in the computer's manual), which causes Setup to write the drive TYPE (and other) information into the computer's CMOS, which is a battery backed memory area that the computer reads and then compares to what it actually detects in the system each time it is turned on. If there is a discrepancy, an error is issued and you are prompted to run Setup to update the CMOS information.

Example of a SETUP menu: <pre class="fixed_text">                   SELECT AN OPTION

0 - SYSTEM CHECKOUT 1 - FORMAT DISKETTE 2 - COPY DISKETTE 3 - PREPARE SYSTEM F. MOVING(PARK HEADS) 4 - SETUP 5 - PREPARE/LOWLEVEL FORMAT HARD DISK 6 - END DIAGNOSTICS

SELECT THE ACTION DESIRED </li></ol> </li></ol>

In this example, choice number &quot;4 - SETUP&quot; would be appropriate for configuring the system for the first and/or second floppy disk drive.

Once the newly set floppy drive TYPE has been set and saved, the computer will reboot automatically in most cases, and the floppy drive should be ready for use.

Keywords: KB75564

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