The very nice HP 41 repair manual refers in large part to a test module, and other special test gear which naturally is not available anywhere. Equally naturally, you need it to diagnose effectively and easily, unless maybe you have detailed design info of the calculator.
Since the module consisted apparently of a program rom and possibly other logic parts, it clearly could be made, given information. So could any other test fixture.
Has anyone ever come across information sufficient to construct and program these items? Or found one surplused out by HP (hah)?