M226 Register

This document describes the M226 module, which contains seven 1-bit storage flip-flops. These modules are used to form 18-bit capacity registers in the central processor of the PDP-15, including the Data Switch (DS), Index (XR), Memory Address (MA), Limit (LR), Program Counter (PC), Output Buffer to Memory (MO), and Memory Input (MI). The module also includes mixer-type logic for A, B, C, and I bus gating. It specifies standard TTL level inputs and outputs, with one open-collector output on pin BM1, and a maximum power dissipation of 5V at 260 mA.