1st stage loader for IMSAI - need ascii to binary conversion

[Tony Duell]

> reminds me of the TRS-232
> It was an aftermarket printer interface ("RS232") that operated off of the
> cassette port of the TRS-80

There was a circuit for that in an old issue of Byte magazine. It was 
daically just an Op-amp that detected the state of the cassette output 
line. The output of said op-amp swung to the supply rails (+/-9V IIRC) 
and was the RS232 output :-)

Also, didn't one of the early Radio Shack modems have a switch on it to 
make the 'RS232' input actually the same levels as the Model 1 cassette 
port, so you could use it with a plain Model 1 with no RS232 interface 
(although with special software, of course)

-tony