rbraun@spdcc.COM (Rich Braun) (03/16/91)
My company does much of its C source code development under DOS, and is currently switching over to a DOS extender product to break the 640K barrier. Recently I started to play with the DOS cross-development support provided by SCO, and I must say I'm pleasantly surprised at how easy it is to set up and at how much faster the compiler and linker run under Unix than under DOS. (Microsoft C running in 386 native mode, producing code for an 8086, compiles a whole lot faster than it does in 8086 mode.) Now the question I have for SCO and third-party vendors is this: is there any way to cross-develop under Unix for an extended DOS target environment? This is not a particularly urgent need for us, but it's oh-so-much-nicer to use the Unix development environment than the DOS environment, particularly considering the speedup of the 'make' process. And given our shift to DOS extenders, we cannot make much use of the SCO cross- development environment as it stands today. -rich
bill@camco.Celestial.COM (Bill Campbell) (03/17/91)
In <6923@spdcc.SPDCC.COM> rbraun@spdcc.COM (Rich Braun) writes: >My company does much of its C source code development under DOS, and is >currently switching over to a DOS extender product to break the 640K >barrier. >Recently I started to play with the DOS cross-development support provided >by SCO, and I must say I'm pleasantly surprised at how easy it is to set >up and at how much faster the compiler and linker run under Unix than >under DOS. (Microsoft C running in 386 native mode, producing code for >an 8086, compiles a whole lot faster than it does in 8086 mode.) >Now the question I have for SCO and third-party vendors is this: is there >any way to cross-develop under Unix for an extended DOS target >environment? >This is not a particularly urgent need for us, but it's oh-so-much-nicer >to use the Unix development environment than the DOS environment, >particularly considering the speedup of the 'make' process. And given >our shift to DOS extenders, we cannot make much use of the SCO cross- >development environment as it stands today. >-rich I am not real familiar with ``DOS extenders'' are these something like Hamburger Helper? More seriously I developed the conversion program for Microrim that converts old versions of R:BASE applications to R:BASE 3.x. I did this entirely on SCO Xenix (originally 2.2.4) and the ability to use the Unix tools was invaluable to me since I break out in a violent rash whenever I get in the same room with a DOS machine. I did all the development and testing under Xenix and would do a final compile with the -dos option to the compile to create the .exe file. The biggest problem I had was when Microrim wanted to be able to compile the source under DOS was that I had to make all my include library files DOS-compliant file names. I had never worried about what I put in front of the .h and .c and several files (like termcodes.h) had to be shortened. It also made me appreciate how kludgey the Microsoft library and make are. -- INTERNET: bill@Celestial.COM Bill Campbell; Celestial Software UUCP: ...!thebes!camco!bill 6641 East Mercer Way uunet!camco!bill Mercer Island, WA 98040; (206) 947-5591
rbraun@spdcc.COM (Rich Braun) (03/22/91)
bill@camco.Celestial.COM (Bill Campbell) writes: >I am not real familiar with ``DOS extenders'' are these something >like Hamburger Helper? Heh heh, I suppose so. I just got a piece of junk mail which reminded me of the Unix/DOS wars. It starts out "The NRA has 3 million members. The HRCF has 30,000 members. Does this mean 100 times as many people are willing to fight for their right to own rifles as are willing to fight for gay rights?" The numbers are about 10 times higher for DOS and Unix: there are something like 30 million DOS systems in the world and probably under 1 million Unices. But like the NRA, DOS isn't going away. Hence the invention of the DOS extender. I'm not sure what all the DOS extender products look like, but ideally they'd allow you to compile a program using 386 object code (rather than 8088) and a nonsegmented 32-bit (4 gigabyte) address space. The system interface to DOS then has to put parameters into the 640K low-memory space and switch the processor into 8088 compatibility mode every time you make a system call. A number of compiler companies and others are creating these kinds of products. Xenix and Unix systems running on a 386 often provide cross-compilation support (as compared, say, to using a DOS-native product under a DOS emulator like VP/ix or Merge), but I don't know of any which provide the extended address space characteristics needed to port practically any large program to DOS. -rich