Many folks find the MetaLink assembler (which is free download) to be a suitable choice for working with 8051/8052 assembler code. Here is the download web page: http://www.metaice.com/ASM51/ASM51.htm

You should be aware that there may be some minor syntax differences between source code that assembles on various tool sets. It is not normally rocket science to edit source code to transition the source code syntax to the MetaLink assembler. The above link also has a link to the assembler manual that is essential to understanding all the ins and outs of the MetaLink assembler.

Porting code can be somewhat more complicated if macros were used in the original source code. Particularly true if the target tool set does not have macro capabilities. The MetaLink assembler does support macro capabilities and so should be adaptable to almost all assembler source code.

Another thing that you should be aware of is that the source of errors that you are experiencing may be due to some issues in your procedure. You may not be properly setting command line switches, may not be providing all the correct include files or maybe the source file itself has some problems with missing parts. There may also be issues with the line ends not being formatted with the correct <cr>, <lf> or <cr><lf> characters.

Michael Karas