As filofel says, use the Win32 API. Here's a small hello world example:
.386
.MODEL flat, stdcall
STD_OUTPUT_HANDLE EQU -11
GetStdHandle PROTO, nStdHandle: DWORD
WriteConsoleA PROTO, handle: DWORD, lpBuffer:PTR BYTE, nNumberOfBytesToWrite:DWORD, lpNumberOfBytesWritten:PTR DWORD, lpReserved:DWORD
ExitProcess PROTO, dwExitCode: DWORD
.data
consoleOutHandle dd ?
bytesWritten dd ?
message db "Hello World",13,10
lmessage dd 13
.code
main PROC
INVOKE GetStdHandle, STD_OUTPUT_HANDLE
mov consoleOutHandle, eax
mov edx,offset message
pushad
mov eax, lmessage
INVOKE WriteConsoleA, consoleOutHandle, edx, eax, offset bytesWritten, 0
popad
INVOKE ExitProcess,0
main ENDP
END main
To assemble:
ml.exe helloworld.asm /link /subsystem:console /defaultlib:kernel32.lib /entry:main
Now to capture input, you'd proceed similarly, using API functions such as ReadConsoleInput
. I leave that as an exercise to you.