Identifying the problem

If the system hangs mysteriously, either at boot time, during installation, or shortly thereafter, use these steps to isolate and identify the problem:

1. Confirm that your hardware is listed as supported in the SCO Compatible Hardware Web Pages. If it is not, contact the hardware vendor to get the requisite software or replace the hardware with a supported device.

2. If possible, check a suspected component on another UnixWare 7 system with a similar configuration.

3. If any third-party drivers are installed, such as those supplied with multiport adapters, remove both the driver and the hardware that it controls, relink the kernel, and see if the problem persists.

4. Make certain that your devices are recognized at boot time. Watch the boot display, use cat(1) or vi(1) to examine log files in the /var/adm directory, or use the ``Using the Device Configuration Utility (DCU)''.

5. Check for hardware conflicts between components, including interrupt vectors, DMA channels, and memory addresses. Check for documented incompatibilities or limitations in the Getting Started Guide and the SCO Compatible Hardware Web Pages.

6. If your machine has features such as shadow RAM or memory caching, disable them.

7. Known conflicts exist between video adapters and network adapters. Sometimes, attempts to send or receive data from the network adapter are blocked. To solve this problem, avoid using IRQ 2 (interrupt vector 2) for your network adapter. Some graphics adapters use the additional interrupt, causing the conflict to occur. Check the SCO Compatible Hardware Web Pages for warnings that apply to specific adapters and adapter combinations. Most video adapters that use IRQ 2 have a jumper to disable this behavior.

8. Known conflicts exist between the default RAM buffer base address for the wdn driver for the Western Digital WD8003 and WD8013 networking adapters, and certain motherboards and VGA video adapters. The wdn driver uses the RAM buffer base address, D0000, as a ROM address. This conflicts with motherboards that store CMOS information at this address and with VGA adapters that use D0000 as a ROM address.

   To solve this problem, reconfigure your Western Digital WD8003 or WD8013 networking hardware to use CC000 or C0000 as the RAM buffer base address. Then, reconfigure the wdn driver using the instructions in ``Driver configuration''.

9. If you installed DOS on your hard disk, you may have a partition table that UnixWare 7 system software does not recognize. You must use DOS version 6.2 or earlier. The DOS partition must not have been created with Disk Manager.