character codes, was RE: Really stupid PDP assembler question

I remember those, just, but only on fully mechanical calculators. But I also haev a Victor Comptometer calculator with solenoids mounted over the keys that was used as a printer on a data logging system, so maybe such machines were hacked onto computers too. I've seen early 70's calculators with tiny drum printers. A drum the full width of the paper -- perhaps 15 columns -- with the digits, -ve sign, decimal point, round it and a row of hammers that print the approriate characters. I've also seen them with a typewheel per column which were positioned and then all columns printed simultaneously. And then I've seen one with a carriage containing a single typewheel and a hammer mechanism. One of the strangest printers I've seen came off the data logger for a gas chromatagraph (a Kent Chromalog II if anyone wants to try to find details). There was a typewheel per column with a solenoid to step it round one posisition, and a switch that gave a carry function. It was essentially a long ripple counter. There was a hammer assembly the full width of the paper. You fed in the pulses (the instrument was essentially an integrator), and at hte approrpriate time you fired the hammer. I can't rememebr how the reset-to-zero worked. I don't think there was a separate solenooid for that. Maybe you just fed in a clock signal to all solenoids together and turned each one off when the carry contact flipped or something. -tony