Spencer Chase has hit on a great idea -- using CIS bars, presumably
made for use in scanners.  With scanners selling for under $100 (I just
got one), there should be plenty of surplus CIS sticks turning up, and
more available as older scanners are junked.

Sorry if I came in late, but I question the need for high (300 dpi)
resolution and precise alignment for the purpose of reading music
rolls.  150 dpi is more than adequate to reproduce a page of text or
sheet music, and 75 dpi will be just a little fuzzy.  To get a good
"picture" of a roll should not require more than 75 or 100 to the inch.

Especially since software will analyze each hole and re-center it to
the correct position, before translating it into a musical note event
or copying it onto a roll to be punched.  Certainly software could
track the roll as it wandered left and right.

I wonder if a fairly cheap and quick system could be built from an old
scanner by parking its light and sensor bars in the middle of its flat
bed and scrolling the roll past it, just off the glass, while some
custom hacked hardware and software kept sucking the pixels out of the
CIS bar?  Bet someone's tried that already.  The expense and precision
would be in the roll transport and guides, but we have lots of folks
here who can build a fine spoolbox.  Again, excuse me if I'm missing
something.

I do like the idea that newer, higher speed CIS bars can be clocked
faster to let the roll pass by much faster than it would normally be
played.

Mike Knudsen