They function differently because they are two different versions. If it's the same program but a different version, presumably the newer one is the one to use. If they're two different programs, you'd have to see which software has the best function set. I'd be weary of using a program from 1986 if it hasn't received any attention since then (i.e. new versions).

> RSEG DATA
> old one(1986):ok
> new(1997):illegal or missing directive

Check documentation of new program to see what the correct format is. Make sure DATA has actually been defined.

> AA EQU (BB/8)+20H
> To this :
> old :invalid relocatable expression
> new:ok

If it works in the new program, keep the new program and forget about it. The symbol "BB" is relocatable, which means its address can't be determined until link-time. The previous version wasn't able to handle such a condition. The new version can, which is a good thing.

Overall recommendation: Check the documentation and tend to stick with the newer software.

Craig Steiner