The comparison was gated with the output of the template memory, causing the sampling to be done near the center of each hole (width-wise).Īt the end of each camera scan, the two data memories were swapped.Īlso at the beginning of each camera scan, a counter was initialized, and then counted each template memory bit as the camera scan progressed. The comparison was done using a 2-line to one of four decoder to easily detect Note-ON and Note-OFF. The digitized camera video was also compared with the recorded video from the previous scan (stored in the the other data memory. In `use mode’, the camera video was recorded in one of the other memories. Each of the template `images’ consisted of several consecutive bits in the memory. Later, in `use mode’ the roll or book was fed through the machine, the system was effectively sensitive only to the light that passed through the centers of the holes in the book.Įach camera scan of the roll or book traversed from one side, and as it went the memory address incremented at the camera pixel rate to 4096 across the width of the book. When the template was inserted between the light source (a florescent tube powered with DC) and the line-scan camera, the resulting digitized `video’ was recorded in on of the memories, that I called the template memory. Care was taken to make the templates with exactly the same hole spacing as a tracker bar, but with holes about half the diameter of the tracker bar hole width. Metal templates were made for each of the different kinds tracker bars to be supported. The FAX machine had a line-scan CCD camera, analog compensation and quantization for the video, and several channels of 1-bit memory. Many years ago I made a piano-roll (and band-organ book) reader from parts of an old FAX machine. At it’s peak the player was in 85% of pianos sold and the home entertainment system of choice. I will follow them up, as I rebuild players and want to hack a roll perforator to preserve old rolls and bring new music to this old digital realm. A player running on a suction source is as boring as hearing recordings that have been compressed or peed on by mp3. This should be done in midi with a control in real time or edited into the work.
Whats missing from a roll conversion to midi, is the absolute joy of playing with your feet the volume of your own expression. These players were fully automatic, incl reroll and shutoff. This was binary weighted 1-2-4-8 in 1913! Midi only uses twice the bits but for each note. The exception of course were the reproducers like Aeolians DuoArt with 4 bits for each half of the keyboard that controlled volume. Players never encoded the soft pedal only the damper pedal. Tracking is disconnected, but should be hooked up with a servo to the two fingers at each side of the tracker bar. An Aeolian spool box no doubt, the finest.
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