Differences from QB
Since version 0.17, FreeBASIC introduced a -lang command-line option, that is used to change the language compatibility mode. Use the -lang qb option when compiling to select the most QB compatible parser. All differences listed below assume that -lang qb was used.
- FreeBASIC is written for 32-bit operating systems and a 32 bit DOS extender, and cannot utilize code which depends on 16-bit DOS, 16 bit assembly or memory model (segment & offset, XMS/EMS, ...).
- DEF SEG is no longer necessary and will not work - any code which POKEs to video memory this way will no longer function, however, for DOS it can be easily rewritten using DPMI features.
- CALL INTERRUPT no longer functions, as it relies on 16-bit DOS. DOS interru