CL-GD5426 with 512K of video memory
Windows 3.1  256-color driver installation:

CL-GD5426 systems with  512K of display memory need to copy the 256_1280.drv
file from \512K directory into the Windows 3.1 SYSTEM sub-directory.

CL-GD5428 systems with 512K of video memory will not need to copy the
256_1280.drv from the \512K directory.