Paper tape encoding scheme needed

From: Bill Richman <>
Date: Thu Apr 11 23:24:49 2002

I've been doing some web searching and reading the "TV Typewriter"
book concerning puched tape encoding schemes, and I'm a bit confused.
I've written a program to punch tape on my PC, and a short bit of code
to read the tapes on my IMSAI 8080, but there are some problems.
Since the unpunched tape leader looks just like a "zero" to the tape
reader, I usually end up with some extra 0's at the start of my
programs on the IMSAI. Also, I have a feeling that the tape reader
may "eat" some of the codes if they're things like X-ON, X-OFF, etc,
although I may be wrong. If I'm going to do something along the lines
of using two 4-bit values to represent each byte, or an escape code to
distinguish real 0's from leading blanks, and maybe include a
full-width (FF) punch every foot or so to allow for easy folding,
while having the reader software ignore them, I'd like to follow some
kind of established standard. Can anyone give me any pointers on

      -Bill Richman (
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Received on Thu Apr 11 2002 - 23:24:49 BST

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