Probleme ASM

Running target pre-build steps
CL main.c /AT boot.com
Microsoft (R) C/C++ Optimizing Compiler Version 8.00c    
Copyright (c) Microsoft Corp 1984-1993. All rights reserved.
main.c
boot.asm(1) : error C2143: syntax error : missing ';' before 'constant'
boot.asm(18) : error C2059: syntax error : 'bad suffix on number'
boot.asm(29) : error C2059: syntax error : 'bad suffix on number'
boot.asm(30) : error C2059: syntax error : 'bad suffix on number'
main.c(8) : error C2059: syntax error : 'string'
Process terminated with status 2 (0 minutes, 0 seconds)
0 errors, 0 warnings
 

boot.asm
L1.    .286
L18.  org                07c00h
L29.  mov bp,7c00h
L30.  mov sp,7c00h

main.c
L8.   extern "C" void BootMain()