I'm not sure what would be best myself. I've noticed that there are files with .s19 extension (Motorola) .hex (Intel) ASCII and .bin (binary). Also,
Correction: The version of TASM I used was a DOS program; it would run under MSDOS, IBMDOS, etc. The current version of TASM (3.2) is compiled with Visual C
You might want to check out TASM (for DOS, runs under Windows in a DOS box), found at: Squak Valley Software - Telemark Cross Assembler (TASM) Home Page As far
For Windows I use Notepad++ for text, frhed for HEX. For OS X I use TextWrangler for text and hex. All are free. Notepad++ is found at: .:: NOTEPAD++ ::.