System Hangs with Zenith Z-Note

• Microsoft Windows operating system versions 3.1, 3.11

SUMMARY

On the Zenith Z-Note laptop, the system may stop responding (hang) if you move the mouse quickly (for example, if you rapidly select and delete text). The problem is not application-specific and may also occur in MS- DOS. A BIOS upgrade from Zenith is required to correct the problem.

MORE INFORMATION

It usually takes several repeated actions to cause the problem.

A BIOS problem may cause the mouse driver to hook IRQ 0, the system timer interrupt. This can be confirmed by using the Microsoft Diagnostic utility (MSD.EXE) supplied with Windows 3.1 to check IRQs. IRQ 0 will be shown correctly as the system timer interrupt, but will be handled by MOUSE.COM.

Zenith has confirmed this to be a problem with BIOS versions earlier than 4.1E in its Z-Note laptop computers. The problem is only known to occur with Windows 3.1 and Microsoft mouse driver versions 8.20- 8.20a.

Zenith Z-Note computers use an EPROM flash BIOS. Upgrades are available from CompuServe or Zenith's End User BBS. The upgrade BIOS revision is version 4.1E.

For further information contact Zenith technical support.

The Zenith Z-Note is manufactured by a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability.