ech@spuxll.UUCP (Ned Horvath) (07/25/84)
The actual use of the halt-and-branch is due to the fact that there were two start buttons on the 1401: a simple resume and a reset-resume. Neither cleared the program counter, but the reset-start would clear the (suspended) branch (thereby continuing after the halt without taking the branch). Thus the operator could transmit one bit to the program by his choice of start button (no console, remember!). =Ned=