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 Hardware Compatibility Handbook or SCO's Compatible Hardware Web Pages. If it is not, SCO recommends that you use supported hardware.

2. If possible, check a suspected component on another machine with the same configuration (under an SCO OpenServer system, not MS-DOS).

3. If any third-party drivers are installed, such as those supplied with multiport cards, 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(C) or vi(C) to look at the /usr/adm/messages and /usr/adm/syslog files, or use the hwconfig(C) utility.
   
   
   
   

5. Check for hardware conflicts between components, including DMA, interrupt vectors, and memory addresses.
   Check for documented incompatibilities or limitations in the SCO Hardware Compatibility Handbook or SCO's Compatible Hardware Web Pages.

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

7. If you have a DOS partition installed, verify that it follows the guidelines in ``Physical and virtual DOS drives'' in the SCO Merge User's Guide.
   
   
   

8. If your hard disk has more than 1024 cylinders, you must follow the restrictions described in ``BIOS support for disks larger than 1024 cylinders''.
   
   

9. If your video card is incorrectly installed, the system can also fail.
   Check the following:

   • Read ``System reboots from Boot Disk or screen blanks after Boot: prompt''.

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

   • Known conflicts exist between the default RAM buffer base address for the wdn driver for the Western Digital WD8003 and WD8013 networking cards, 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'' in Configuring Network Connections.

   • Known conflicts exist between some brands of 16-bit VGA boards and floppy or tape data transfer. If you experience data corruption during floppy or tape data transfers, try configuring the card to 8-bit mode or put it in an 8-bit slot.
     
     Consult your hardware documentation for more information.

10. If you did a low-level format of your hard disk, you may have a format program that does not work.
    
    Format programs that are known to work are DOS Debug and Speedstor.
    
    
    

11. If you installed DOS on your hard disk, you may have a partition table that SCO OpenServer system software does not recognize.
    
    You must use DOS version 6.0 or earlier. The DOS partition must not have been created with Disk Manager.