In 1977 I bought the resident assembler/editor MP-E, paper tape version, from SWTPC. I needed to resurrect it last summer because I could not find a convenient cross-assembler on internet. I was developing new code for interfacing my AN/FGC-25 teletype set to my 6800 homebrew. Here is a demonstration video showing how to use this resident assembler in any 6800/MIKBUG based computer with at least 8Kbyes memory (mine has 8K).