Hi Alex,
I just figured out how to walk the MCB chain. Here's an NASM assembly program (not quite finished but does walk it from 'M' to 'Z', the end of the MCB chain). Thanks must go to the fabulous book 'Undocumented DOS' by Andrew Schulman, Tim Patterson, Ralf Brown et. al) which I bought 15 years ago.
I happened to get that book from a previous employer a few years ago and decided to start reading it cover to cover a few months ago to reminisce about the good old DOS days and that was what made me decide that contributing to FreeDOS would be a bit of fun :)
Anyway, back to what you are working on, I just wanted to mention that the source for the MEM command might be useful to you although it's written in C and not assembler and you have probably already figured out everything you need to do. It's in CVS - http://cvs.sourceforge.net/viewcvs.py/freedos/mem/source/mem/mem.c?rev=1.11&view=auto The version in CVS doesn't try and find the master environment although I am working on that myself. I am also using the technique of looking for a PSP with parent PID == own PID. I suppose that with this technique it is safe to assume that the process with the higest PID is the most recently loaded one and hence is the one with the master environment you need to edit?
By the way, do you have the disk from the book? Mine didn't come with the disk :( Is there any chance you could send the files if you happen to have the disk?
Regards, David ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
