Industrial Micro Systems - 4 Line Communications Controller
IMS made a number of Z80 CPU boards of increasing degrees of complexity and sophistication.  The 4800 was their last board. It was an intensely packed S-100 board

Around 1982 IMS change their name to Intercontinental Micro Systems and came up with extremely sophisticated boards.   The CPZ-4800 had a 4MHz Z80 CPU, a single and double density floppy disk controller (WD 1793)  for 8" or 5" drives, two serial ports, two parallel ports, 64K of dynamic RAM on board, memory addressing/management for IEEE 696 16Mg of memory, vector interrupt handling hardware, 2 or 4K or EPROM and a real time clock.  S-100 boards had come a long way!

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