Hello friends,
I am a newbie. During reading the C language, many times these terms come.
1) 16-bit environment or 32-bit environment
2) 16-bit operating system or 32-bit operating system
3) 16-bit compiler or 32-bit compiler
Please tell me what these terms mean. I know what is meant by compiler or operating system. What is referred by 16-bit or 32-bit here.
Thanks for devoting ur time in my query.
> 1) 16-bit environment or 32-bit environment
This is almost the same as 2. However, you can, for example, have a 16-bit environment on top of a 32-bit OS (like a DOS window in Windows 3.1).
2) 16-bit operating system or 32-bit operating system
A 16-bit operating system uses a processor (mode) that only supports 16-bit registers - this means that a single register can only hold an unsigned value from 0..65535. Larger values will have to be dealt with by using multiple operations/multiple registers.
A 32-bit operating system uses a processor (or processor mode) that supports 32-bit registers, where an unsigned integer can be up to a bit more than 2,000,000,000 (2 billion or 2 giga).
3) 16-bit compiler or 32-bit compiler
A compiler designed to generate code for a 16 or 32-bit environment.
Lately, systems with 64-bit (OS, Compiler, Environment) has also come into reality, for example there is a version of Windows XP and Vista that runs in a 64-bit mode. Unsigned long integers here may be up to 2 ^ 64-1, which is some 18-digit number...
Unless you are digging compilers out of the antique-section of the computer stores (e.g. turbo C or Visual C 1.5), you will most likely use a 32-bit compiler these days.
--
Mats
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
Thank you very much matsp,
All my doubts are cleared. Thanks again.
Usually a reference to 16-bit or 32-bit code on the x86 platform is also a reference to real mode or protected mode programming.
It is possible to use 32-bit code under DOS via a DOS Extender and 32-bit compiler/assemblers. DJGPP is a 32-bit DOS C/C++ compiler. MASM, TASM, and NASM are 16-bit and 32-bit assemblers. Rational systems used to have a very good DOS extender that most DOS video games of the day used. I believe Rational Systems went belly up some time ago. DJGPP comes with a less supported DOS extender but is still quite good.
Last edited by VirtualAce; 10-03-2007 at 11:15 PM.
