Encoding of BASIC source code on punched tape

Chuck, loads of interesting stuff, but it doesn't answer Mark's question. What Mark needs to know is: When the IMSAI (or whatever machine) reads these tapes in to run them in BASIC, Does it need to see two characters there? Do they have to be DEL? There are three possibilities that I can see: 1. No, the machine just reads the tapes and ignores DEL. 2. Yes, they can be anything, the machine ignores the first two characters after a CRLF. 3. Yes, they have to be DEL, the machine checks this. I think the first is the most likely, since the machine is supposed to ignore DEL anyway, and this doesn't require any extra code. The machine should accept the input from the tape reader just as if you were typing it at the keyboard - if your terminal is an ASR33, the machine can't actually tell, after all! But you never know. It may even be different on different machines / versions of the system. Incidentally, when I had an ASR33 as my only printing device (bit banging over the PET user port), I never sent any non-printing characters after CRLF. If I'd used LFCR (as many systems do), that would have been a different matter... Philip.