APM/ACPI BIOS questions
#34404 by montreal
Thu Oct 13, 2005 11:02 pm
Hello, this is my first post.

I recently was given a single board computer that connects to an active ISA bus, and I have spent the last 3 weeks bringing it back to life.

While this robust industrial computer has a slow 386DX cpu, it has many other features on it that make me prefer it to a PCI bus Pentium for my home automation.

This computer has a custom written BIOS (QUADTEL/PHOENIX) and requires a setup disket to access the CMOS parameters.

I was unable to locate the original BIOS setup disket but I found two generic utilities on the WEB that let me examine and change the main BIOS features which are universal to many BIOS. The second utility disket lets me access some of the extended CMOS features, but probably not all of them, as they tend to be unique to each manufacturer.

My current problem is that the monitor goes blank exactly 60 minutes after booting up the computer, even if the computer is busy doing a task and I am moving the mouse around the screen. Once the monitor goes blank, no amount of keyboard strokes or mouse movement will wake it up. Control-Alt-Delete will reboot the computer.

Even when the screen goes blank, the disk light keeps flashing as the already started Windows 95 process continues to its logical end (example, a Windows 95 build that takes over an hour to complete).

An exception to this rule occurrs if I boot up the computer with a DOS disket and the screen offers the DOS prompt and waits for a keyboard response. 60 minutes later the screen will go blank, but if I press a key, the screen comes back to life. If I boot up Windows 95 and open a DOS window, then my screen will go blank after 60 minutes, and no keystrokes can bring the monitor back to life.

The green power light on the monitor stays green and does not change to yellow when the screen goes blank, indicating that VIDEO OFF METHOD = "Blank Screen" is being outputed.

In Windows 95, I have disabled all Power Management options.

My conclusion is that there is a video power management feature on the computer that has a 60 minute timer that begins counting down the moment the computer is booted up and once the timer is expired, the screen goes blank. There is some code in DOS that gets activated whenever a keyboard entry takes place which will reset this timer and if necessary, refresh the screen if already blank.

My Windows 95 is not to be able to reset the timer and refresh the blank screen when I press a key or move the mouse.

My mouse is a serial mouse via COM1 and not a PS/2 mouse via a mouse port (no available port), so my mouse may be associated with a different IRQ, that of the COM1 serial port. This would be a problem if DOS uses the keyboard to wake itself up and Windows 95 uses the mouse movement to wake itself up, and if the mouse IRQ is different from the standard, then that could explain why Windows doesn't wake up.

I am assuming that my BIOS has a "VIDEO OFF OPTION" which I need to set to "ALWAYS ON".

I can't get deep enough into my BIOS to confirm this because I do not have the original BIOS utility disket. The BIOS is an unflashable 128 KB. EPROM.

Does anyone know if there is a workaround to get Windows 95 to refresh the timer and refresh the monitor the way DOS is able to do?

Thanks