emigh@ncsugn.ncsu.edu (Ted H. Emigh) (02/06/91)
A couple of recent message have wondered about the various modes of Windows with a 386 and varying amount of memory. The Windows manual states that if your computer has <1MB, then it will run in real mode; if it has between 1MB and 2MB, it will run in standard mode; and if it has >2MB then it will run in enhanced mode. This is not entirely true. Some computers use memory for various other purposes, so that it may not be available. The REAL rules are: 1) Real mode if the amount of extended memory is < 256K. 2) Standard mode if the amount of extended memory is > 256K but < 1M. 3) Enhanced mode if the amount of extended memory is > 1MB. Our department recently bought 2 386 machines. Both came with "1MB RAM." The first, a 386SX, uses 128K of that 1MB for shadowing the BIOS, so that the amount of extended memory is 256K -- standard mode runs OK on it. The seconde, a 386DX, uses all 384K "extra" memory for shadowing the BIOS, so that the amount of extended memory is 0 K. Run your setup program to determine how much extended memory you really have!