Marko Mäkelä wrote:
> What are jumpers SJ1, SJ2, SJ3 for?  You could label all signals.
>   
When the board is initially produced, the uC will not be installed, so 
the jumpers connect the READ/WRITE/SENSE lines from input to output.

I will label the board tonight.
> Also, Kicad <http://kicad.sourceforge.net> is a free (as in speech)
> alternative to Cadsoft Eagle.  I haven't looked at yet, but if it is
> good enough for a mobile phone <http://wiki.openmoko.org/wiki/Gta02-core>,
> it should suffice for any hobby project.
>   
I've downloaded it, and it looks like a nice tool, but I've invested a 
lot of time in EAGLE libraries and designs.  I admit I did not do an 
exhaustive search, but I was having trouble finding a nice way to 
convert libraries and designs to KiCAD.  The scripts I found were 
incomplete or contained errors.
> What about a small prototyping area or a header for all (or unconnected)
> pins of the microcontroller?  The circuit could be more useful if you
> could connect it to something else (e.g., computer, or memory card and
> at least one switch).  I think that a tape drive emulator requires a
> PLAY button with which you can initiate the transfer (or select tracks).
>   
I intended that folks would install a IC socket for the uC, and that 
could accommodate connection to the unconnected pins via a daughterboard.
> If you boot up the computer with SENSE=0, it will "think" that you are
> trying to rewind or fast-forward the tape, and it will be supplying power
> on the MOTOR line.  That is why you need to control the SENSE line in some
> way.
>   
Well, as it is wired right now, SENSE will come up as an input, so I 
think I'm OK.

I'll wire in the voltage divider for MOTOR.

Jim

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