Create a simple BASIC, C, Perl, or whatever program to ask for the input, then have it create a file that your assembly code can INCLUDE. For constant definitions, INCLUDE your file near the beginning of the source, for text and table type data, preceed the INCLUDE statement with ORG type directives to tell where you want the data to go. You could create multiple files if needed.

Thus, you don't have to touch the original source code.

<>< Lance.