The first NASCOM moving head disk controller

The controlled drive is a DRE 3100.
This controller is a monster. It's got its own dedicated Z80B, and in addition to normal
and extra controller functions, it has a dedicated spooler partition and parallel printer interface.
Transfer speed of sector buffer data to/from host is 4 MB/s.

This card interfaces the NASCOM to the four cards below.

These cards contain read and write logic and microcode for generating control signals to DRE 3100.