Microsoft KB Archive/60764

= Microsoft Knowledge Base =

Troubleshooting Steps if MACH 20 Hangs Computer
Last reviewed: September 16, 1996

Article ID: Q60764

The information in this article applies to:


 * Microsoft MACH 20, version 1.0

If the IBM XT hangs on boot-up because of the MACH 20 board, do the following:

 Make sure the machine is a compatible 8088 machine. Check for a conflicting card (for example, a video card).  Check the BIOS date. Make sure it is a workable date. If the date is unknown, the machine must be able to boot; pull the MACH 20 card to find the date. Either the MACH 20 Setup disk will tell you or go to the command prompt and enter the following: a. Enter &quot;debug&quot;. b. Enter &quot;D F000:fff5&quot;. This should return the BIOS date. Compare against good BIOS dates from the following table: IBM ROM BIOS Version: Date   | Machine | Works? | Comments ---  04/24/81|  PC     |  NO    | Original 16/64K 10/19/81| PC     |  NO    | Bug fixes 08/16/82| XT     |  NO    | Original 64/256K 10/27/82| PC     |  YES   | Upgrade to XT level 11/08/82| XT     |  YES   | Bug fixes 01/10/86| XT     |  YES   | 256/640K motherboard 05/09/86| XT     |  YES   | Bug fixes -

 Check to see if the MACH 20 is in slot 8 of an IBM XT. If it is, try another slot. Switch the A (S and F) jumper. Switch the C (R- BIOS caching) jumper. Make sure the 5 2 1 jumpers are set right. Try pulling the memory card, Disk Plus, and try to isolate the problem.</li> Remove the MACH 20 board and try the original 8088 chip to see if the machine works. If the machine works with the 8088 chip and all other steps were followed, have the MACH 20 board sent in for repair or replacement.</li></ol>