I am using MASM 8.0 with Visual Studio 2005 and when I compile the simplest program like the example here it is sooooo big, but when I program for NASM and program for MS-DOS (.com files) they can be as small as like 10Bytes and such....
mov ax, 4Ch
There a couple of things to consider:
[*] 32-bit version of 8086 instructions like MOV REG32, REG32 are usually bigger than their equivalent 16-bit or 8-bit versions. So while an instruction that uses REG8, REG8 could be 2 or even 1 byte, its equivalent for REG32, REG32 could be 5 bytes (these are just examples).
[*] When writing .com files, your assembler will simple translate your opcodes to machine code and write them in a linear way in your destination executable file. Win32 API uses the PE format (Portable Executable). With having this format, you usually can't have PE (EXE/DLL/...) files smaller than 512 bytes. I remember somebody was hacking the PE format to get it smaller but I don't know if that worked. Again the sizes are just examples.