Macintosh Plus with Brainstorm accelerator installed, showing the replacement Toshiba TMP68HC000P-16 16MHz CPU, and the resistor taking the 16MHz clock from the motherboard.

Also pictured are the the chips under the CPU card that can’t be photographed in their entirety without de-soldering card from the CPU and the BBA-14 TSM (Timing State Machine) replacement.

The plus doesn’t like the System 7 boot disk image I have, thus the co-processor not installed error.