Sysgen Omni-Bridge March 1, 1989 OMNI-BRIDGE CONTROLLER DIP SWITCH SETTINGS: In order to install the Omni-Bridge floppy controller, a number of dip switches must be set on the controller card itself. The process of setting these dip switches is automated by using the SETUP utility provided on the distribution disk. A more detailed explanation of these switches is given below. SW1, which is located in the upper left corner of the card, is used to define the type of drives that are connected to the internal connector of the Omni-Bridge when the Omni-Bridge is being used as a primary controller. If the Omni-Bridge is being used as a secondary controller, the position of the dip switches of SW1 do not matter. In this case, the drive types are defined through the INSTALL utility. In the explanation given above, the Omni-Bridge is the primary controller if it is the only floppy controller in the system. (Selecting the Omni-Bridge as a primary or secondary controller is done with SW2 and is explained below.) When the Omni- Bridge is a primary controller, the system must be able boot from drive 0 (drive A:) which is the last drive connected to a standard floppy controller cable which in turn is connected to the Omni-Bridge. Therefore, our controller must know what type of drive is connected to the Omni-Bridge at boot time. Normally the system BIOS knows about the type of drive that the system boots from. However, in cases when the system BIOS was designed before a type of drive existed, our BIOS must inform the system of the type of boot drive. We also set the drive type for drive 1 so that if you are using the Omni-Bridge with only two internal drives and the Omni-Bridge is the primary controller, you do not need to install the DOS device driver OMNIBRG.SYS. SW1 consists of four dip switches. The first two define the type of drive for drive 0 and the second two define the type of drive for drive 1. The switch settings are as follows: off off - 360Kb drive off on - 1.2Mb drive on off - 720Kb drive on on - 1.44Mb drive Also note that 'off' is equivalent to 'pushed in at the bottom' on rocker type switches. A valid configuration would be: 1 2 3 4 on on off on which means that you have a 1.44Mb drive 0 (drive A:) and a 1.2Mb drive 1 (drive B:). You could then boot from a 720Kb or 1.44Mb media, read and write 720Kb and 1.44Mb media in drive A: and read and write 1.2Mb and 360Kb media in drive B:. SW2, which is located in the upper right corner of the Omni-Bridge card, defines the ROM BIOS segment address, the I/O addresses to be used, and the drive speed of 1.2Mb drives. The first two dip switches of SW2 select the ROM (Read Only Memory) BIOS segment address. Normally the factory set BIOS segment address will work. It will not work if other ROM's currently in your system are set at the same segment address as our ROM BIOS. Also note that our ROM BIOS can be disabled if your system BIOS supports all drive types. The settings for the first two dip switches of SW2 are as follows: 1 2 off off - BIOS disabled off on - segment address CA00 on off - segment address CC00 on on - segment address CE00 The third dip switch of SW2 is used to define the I/O addresses used by the Omni-Bridge. What this does is selects the Omni-Bridge as a primary controller or a secondary controller. As a primary controller, the I/O addresses 3F0-3F7 must be used. These are selected by setting the third dip switch of SW2 off. You would most likely use the Omni-Bridge as a primary controller in a PC or XT compatible where the original floppy controller can be removed. As a secondary controller, the I/O addresses 370-377 must be used. These are selected by setting the third dip switch of SW2 on. You would most likely use the Omni-Bridge as a secondary controller in an AT or compatible where the floppy disk and hard disk are combined on to one card and it is not possible to remove the floppy controller without removing the hard disk controller. You could, however, use the Omni-Bridge as a primary controller in an AT compatible by removing your floppy controller if your system has a stand alone hard disk controller. As well, you could use the Omni-Bridge as a secondary controller on a PC or XT compatible and leave your current floppy controller in your system. The fourth dip switch of SW2 is used to select the type of 1.2Mb drive that you have connected to the Omni-Bridge, if you have any connected at all. If you have no 1.2Mb drives connected to the Omni- Bridge, or the 1.2Mb drives are SYSGEN 1.2Mb drives, this switch should be left in the factory set 'on' position. If you do have a 1.2Mb drive connected to your Omni-Bridge, you need to determine if the drive is a dual speed drive or a single speed drive. Normally you can tell if it is a dual speed drive or not by looking for a sticker that indicates that the drive supports 300 and 360 RPM. Most drives are dual speed drives. However, most dual speed drives come configured to operate as a single speed drive. In order to operate as a dual speed drive, a jumper needs to be changed on the drive. The particular jumper depends on the drive manufacturer and should be documented in your drive manual. Some of the more common drives have been documented in our Omni-Bridge manual. If your drive is a dual speed drive and has been configured as dual speed, the fourth dip switch of SW2 should be set on. If you determine that you have a single speed drive or you have to use your dual speed drive configured as single speed, you will need to contact SYSGEN about getting a version of the Omni-Bridge controller with two crystals. When you get this version of the Omni-Bridge controller, you will need to set the fourth dip switch of SW2 off.