MCP-1600
The PTA serves to generate new microinstruction fetch addresses as a function of several parameters.Microcode could be developed using a DEC LSI-11 computer with the KUV11-AA Writable Control Store (WCS) option.This option allowed programming of the internal 8-bit micromachine to create application-specific extensions to the instruction set.The WCS is a quad Q-Bus board with a ribbon cable connecting to an open MCP-1600 microcode ROM socket."It works well enough to execute the first few dozen p-code instructions of the ACD PDQ-3 boot ROM before going into the weeds."