Yes it is ascii, but not very useful to the average punter, since it needs to be decoded into coordinate pairs, rather than alternate lines of argument descriptors and arguments.
If gnmp really wants to see how to decode a dxf file then if you email me on greglocock at yahoo.com.au I'll send you a qbasic program that extracts lines, only, and displays them. Alternatively look up the reference material in the appendix on dxf files, in the Autocad manual, which gives you a few hints to write your own program, and some sample code. Cheers
Greg Locock