Its MRDC (memory read control) it is a maximum mode pin in 8086 microprocessor
WHAT IS THE PINS CONFIGURATION OF 8086?
The MN/MX- ping on the 8086 is pin 33.
See the related link, below, for the 8086/8088 pinout.
Pin 28 on the 8086/8088 is M/IO-, in minimum mode. The equivalent pin on the 8085 is IO/M-, and has opposite polarity.
The 8086 family of microprocessors, including the 8086, 80C86, and 80C86AL, are presented in 40-pin DIP packages.
40 PINS
In the 8086, pin 35 (A19/S6) is used as the high order address bit during the beginning of each memory access cycle. Afterwards, it is a spare status pin and is unused.
it is a 16 bit microprocessor & it has 40 pin .
The 8086 comes in a 40 pin package with 2 ground pins and one power pin; the remaining 37 signal pins every single one is important.
The BHE (Bus High Enable) pin on the 8086 is latched by the 8282 in order to indicate if a write cycle is a word (BHE=1) or byte (BHE=0) cycle.
The flow of information on the data bus is bi-directional. When status pin S1 is high, it is a read from IO or memory towards the CPU; when S1 is low, it is a write. S1 is present on the 8085. On the 8086/8088 it is inverted and combined with DT and called DT/R-