These early mini computers were cost optimised. Their earlier mainframe cousins often had features to easy "Initial Program Loading". The IBM 1401 had a load b

These early mini computers were cost optimised. Their earlier mainframe cousins often had features to easy "Initial Program Loading". The IBM 1401 had a load button that was hardwired to read a single punchcard (80 6bit words) into memory locations 001 to 080 and jump to it. The CDC6000 had a panel with 144 toggle switches, acting essentially as a 144 bit bootrom. (12, 12bit words) These were expensive mainframe computers, so they could usually afford some budget towards IPL functionality. But I guess even these cheaper minicomputers were expected to stay on long enough that there was little point spending money on IPL functionality to make cold booting easier.