key block 326 this will let the camera 58 go to the first limit switch 247 nearest the stepper motor 57 on the left end of the linear actuator 56 as shown in fig1 block 330 there is a second limit switch 248 on the far right end of the linear actuator 56 the camera 58 will continue to move down the linear actuator 56 until the first limit switch 247 is activated the computer software will continue looping until an input is received that the home needle is found which can be an arbitrary needle selected by the operator blocks 332 and 334 after the home needle is found block 338 the operator can push the 34 set home needle 34 button block 336 to initialize the program and provide input to the computer as to the position of the home needle initialization is now complete and the system is ready for utilization the main body of the computer program is flowcharted in fig8 the first step is to start the main loop block 340 there is a 34 wait until a key is hit 34 block 344 that requires the striking of the desired key block 342 then reading the ascii code of that key block 346 there are fourteen different functions possible or in other words fourteen different keys that can be pushed the first function is to move the camera 58 in a positive direction.