Industrial Micro Systems - Z80 CPU (451) Board
IMS made a number of Z80 CPU boards of increasing degrees of complexity and sophistication.  The 451 was their first board.

The board had  really nothing more than the Z80 CPU and the necessary circuitry to interface to the S-100 Bus.   That said the circuitry was very nicely laid out and clean. Jumper JA (1-3) allowed 0, 1 or 2 wait states.  Jumper JB (1-8) sets the high order bits for a Power on Jump Hex address and JC (1-2) selects 2 or 4 MHz operation.  The S-100 MWRT (pin 68) can be generated on the board with jumper JE.
 
The manual for this board can be obtained here.

Other IMS S-100 Boards
16K RAM   32K RAM    64K DRAM    80186 CPU    FDC 400    FDC 930    HDC    IO Board    Z80 CPU  
8K RAM   4 Line Serial     CPZ 4800   LANS100    CPS-Q6A   Other Boards