Fwd: unknown data tape

[Tony Duell]

> I don't know about the content, but units that used these cassette tapes to
> simulate a paper tape reader or punch were not uncommon in the early-to-mid

Probably the most common was a verstion of the TI Silent 700. It had a 
box fitted on top containing 2 tape drives and a handful of boards of 
logic to control them. You could use them like punches or readers 
(save/load data either locally or to the line, copy data between the 2 
tapes, 1 character at a time I think, etc).

As an aside, I bought a Microwriter the other day. It contains an 1802 
processor. While looking for the user manual for that chip (I found it), 
I came across the manual for the RCA developemnt sysetm for the 1802. 
Said manual contains scheamtics and ROM sources, BTW. And in the same box 
were the binary paper tapes for the editor and assembler and a cassette 
containing the same stuff to be read on such a Silent 700

Another format (or at least I think it's another format) used the full 
width of the tape in one go and recorded 2 tracks. A pulse on one track 
was a '0'. A pulse on the other track was a '1'. A pulse on both tracks 
together was some kind of marker. The HP9830 uses this format, the 
'maker' being na end-of-byte marker. I think other machines used it for 
end-of-file or similar. 

-tony