Microsoft KB Archive/29479

MACH 20 README.DOC: MACH 20 Disk Plus Drive Compatibility PSS ID Number: Q29479 Article last modified on 11-22-1994 PSS database name: HARDWARE

1.00 MS-DOS

Summary: The following information is from the MACH 20 README.DOC file for version 1.0.

MACH 20 DISK PLUS DRIVE COMPATIBILITY
The connector on the Disk Plus controller board is identical to the connector on an IBM PC Disk Controller card. Therefore, to use a drive with Disk Plus, the drive must have connectors that are identical to those of a PC drive. There are two connectors on a standard IBM floppy drive–a four pin connector for power, and a 34-position edge connector used to connect the drive to the disk controller via a ribbon cable. A number of companies manufacture 5.25 inch 1.2MB drives that have cable connectors compatible with standard IBM PCs. However, a 1.2MB drive is half the height of a regular PC or PC/XT slot. To mount a 1.2MB drive in a regular slot, you will need a special bracket to fit the drive in the slot and a blank cover for the empty half of the slot. When you buy a 1.2MB drive, make sure that the parts necessary to mount it in your machine are included and that both connectors are compatible with PC cables. To use a 3.5 inch 1.44MB (2MB unformatted) drive with Disk Plus, the drive must be an ANSI or “media sensing” type drive with no connection to pin 2 of the logic cable. Media sensing drives detect the hole in a disk to determine whether it is a 1.44MB disk. Most 3.5 inch drives require a PC cable connector adapter for both the power cable and the logic cable since the drive connectors do not match standard IBM PC cable connectors. 3.5 inch drives are also half the height of a regular slot, and require the special bracket and blank cover described above. In addition, they are not as wide as a regular slot, and require a 5.25 inch adapter kit to make them fit in place of a 5.25 inch drive. Some manufacturers offer 5.25 inch compatible kits for 3.5 inch drives that include the drive and the mechanical and electrical adapters required to make the drive fit in a 5.25 inch half-height slot. Among these kits are:

  IBM P/N 6450258 3.5 inch 720K Diskette Drive   Sony MP-F63W-31D 3.5 inch 720K Drive with Kit   Sony MP-F73W-31D 3.5 inch 1.44MB Drive with Kit*   Universal Kit for ND 352 Floppy Drive (for the Toshiba FDD 4603 3.5 inch 1.44MB drive)**   The Sony MP-F73W-31D 3.5 inch 1.44MB drive is shipped configured to be drive 0. Since all drives for an IBM PC, PC/XT, or PC AT must be configured to be drive 1, all 5.25 inch floppies are shipped configured for drive 1. Therefore, if you purchase a Sony MP-F73W-31D 3.5 inch drive, you will need to change the drive select switch. The drive select switch is a small, black slider switch with four possible settings. It is recessed into the side of the drive towards the back. If the faceplate of the drive is towards you, and the printed circuit board is upwards, the switch is on your left. The drive is shipped with the switch set to the furthest position away from the faceplate; you must move it one click towards the faceplate. If the switch is in the wrong position, the motor will turn but the drive select light will not go on when you ask for a directory of the drive. **If you place the Toshiba FDD 4603 3.5 inch 1.44MB drive in front of you with the printed circuit board facing upwards, and with the drive slot to your left and the cable connector to your right, you will see an 8-pin jumper block recessed into the upper-right corner of the printed circuit board. This jumper block has two jumpers, which should already be in the correct position for Disk Plus. If the jumper pins were numbered as shown below, the correct positions would be connecting pins 2 and 3, and pins 7 and 8: 4  |8| Disk       |3|  |7|       Cable Slot      |2|   6        Connector 1   5 

If the jumpers are not set correctly, you will need to change them with a pair of tweezers.

KBCategory: kbref kbhw KBSubcategory: Additional reference words: 1.00 noupd readme

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================================================================ Copyright Microsoft Corporation 1994.