Here are a number of the hex files from the projects in Building Simulated Aircraft Instrumentation. You should be able to download them and program a PIC16F628-20 with them. 

ADF.HEX is for the project in the Stepping Motor ADF/RMI Head chapter.

AIRCORE1.HEX is for the project in the Air-Core Vertical Speed Indicator chapter.

ALTIM.HEX is for the project in the Stepping Motor Sensitive Altimeter chapter.

DG.HEX is for the project in the Stepping Motor Gyro Compass chapter.

VGYRO1.HEX can be used for both the Servo Attitude Indicator and Servo Turn Coordinator Projects, though you will have to set the min and max values for the servos differently.

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