I am new user in 8051.Now I am doing a project .
Finishing the source code ,I assemble the source code .there are two kind of asm51.exe in my computer. One is made in 1986,the other is made in 1997.But two reacted differently to the same source code.The old one (1986)found 50 errors in my source ,but the new one only found 5 errors .

For example,

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


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

I don't know the reason,please tell me !
thanks!

michael