the key was released. When released, the lever would catch the projection so the cam was now in home position. This resembled a simple clock escapement, and prevented repeated typing. (The "key-down" anti-repeat stop could be removed, so that fast repetitive typing could be done, but this change was difficult to undo.) Carriage return was done by a non-stretch very durable textile tape attached to the platen advance mechanism at the left of the carriage. For a return, the tape wound up on a small reel operated from the drive system through a clutch. A cam engaged the clutch; it was disengaged by the left margin stop, perhaps directly, perhaps via another cam. A light-torque spring kept the return tape wound on the reel. The basic mechanism looked just like an IBM electric typewriter from the late 1940s. In fact, some Flexowriter parts were identical in fit and function to the early IBM electric typewriters (those with rotary carriage escapements, a gear-driven power roll, and a governor-controlled variable speed "universal" (wound-rotor/commutator) motor). The early IBM rotary-escapement proportional-spacing typewriters (three wheel rotary escapement, spur gear differentials) had code bars to control the amount of carriage movement for the current character. They were operated by the cams. However, the Flexowriter's mechanical encoder was a very different and far more rugged design, although still operated by the cams. Flexowriters (at least those prior to 1969) do not have transistors; electrical control operations were done with telephone-style (E-Class) relays, and troubleshooting often involved problems with the timing on the relays. Another reader has also found that the timing settings of the various leaf switches (such as in the tape reader) are also important. The screws used in the Flexowriter were unique, having large flat heads with a very narrow screwdriver slot and a unique thread size and pitch. This may have been a conscious decision. Another reader found that standard 4-40UNC threads appear to fit some of the cover-attachments; internally, the headless set-screws require fluted Bristol keys, which were not commonly available in Great Britain. There was a holder for a large roll of paper tape on the back of the unit, with tape feeding around to a punch on the left side, toward the rear. The tape reader was on the same side, toward the front, and was essentially identical to the reader shown on the front of the square housing in the