R, S and B Series logic probes

Tools for classic Flip-Chip logic

Part of the PDP-8 Hardware Documentation
by Douglas W. Jones
THE UNIVERSITY OF IOWA Department of Computer Science

DEC R, S and B series logic use voltages that seem alien to those whose hardware experience began after 1970. The supply voltages are +10 and -15, and the logic levels are 0 (active pull-up) and -3 (passive pull-down). In working with this logic, I have developed several logic probes: