LFB is indeed active. Linear and page mode drivers are two different drivers. Furthermore, if you set the buffer start to 32 MB, the image on the monitor is expectedly corrupted. I don't have 1 MB memory modules, only 4 MB. Therefore, I can't use less than 16 MB of memory.

Darmok wrote on Today, 18:23:

The motherboard is based on the opti495slc chipset. This chipset supports 64 MB of memory. The BIOS sets the actual memory size to 32 MB. Accessing addresses above 32 MB triggers data transfers with devices on the ISA bus. Since the addressable size of the ISA bus is 16 MB, it appears twice in addresses above 32 MB. The megabyte immediately after the thirty-second megabyte contains 384 KB of ROM and the video page buffer. The next megabyte is free. Megabytes start counting from 0, so I set the LFB to start at 33 megabytes. The BIOS doesn't have an option to specify a memory hole at address 15 MB.

Cool, is that motherboard information available on TheRetroWeb ?