Comparison between 8085 and 8086 Microprocessors

 

S.No.	8085 Microprocessor	8086 Microprocessor
1	It is a 8 bit microprocessor.	It is a 16 bit microprocessor.
2	It has 16-bit address lines.	It has 20-bit address lines.
3	It has 8-bit data bus.	It has 16-bit data bus.
4	It has 5 flags.	It has 9 flags.
5	It does not support pipelining.	It supports pipelining.
6	It does not support memory segmentation.	It supports memory segmentation.
7	The 8085 operates on a 3MHz Clock Speed.	The 8086 operates on 5MHz clock speed.
8	The 8085 microprocessor has 6500 transistors.	The 8086 microprocessor has 129000 transistors.
9	It is accumulator based microprocessor.	It is general register purpose register based microprocessor.
10	It has no minimum or maximum mode.	It has minimum or maximum mode.
11	It has 64KB memory.	It has 1MB memory.
12	It operates on clock cycle with 50% duty cycle.	It operates on clock cycle with 33% duty cycle.
13	In 8085 microprocessor only one processor is being used.	In 8086 microprocessor more than one processor is being used(additional external  processor can be used).

Comparison between 8085 and Z80 Microprocessors

S.No.	8085 Microprocessor	Z80 Microprocessor
1	Data Lines are MULTIPLEXED	It has no MULTIPLEXED lines
2	74 instructions	158 Instructions
3	Operates at 3 to 5MHz	Operates at 4 to 20 MHz
4	It has 5 interrupts	It has two interrupts
5	No on board dynamic memory	It has on board logic to refresh Dynamic memory
6	It contains no Index register	It has two Index register
7	It contains SIM & RIM	It contains no SIM & RIM

Comparison between 8085 and MC6800 Microprocessors

S.No.	8085 Microprocessor	MC6800 Microprocessor
1	It operates on Clock frequency of 3 to 5 MHz.	It operates at 1 MHz frequency.
2	8085 has no Index register.	It has one index register.
3	8085 has on board clock logic circuit.	No clock logic circuit.
4	8085 has one Accumulator Register.	MC6800 has two Accumulator Registers.
5	8085 has five interrupts.	MC 6800 have two interrupts.
6	It has total 674 Instructions.	MC6800 has total 72 instructions.

Comparison between 8086 and 80386 Microprocessors

S.No.	8086 Microprocessor	80386 Microprocessor
1	It is a 16 bit microprocessor and it is first 16 bit microprocessor after 8085(8-bit).	It is a 32 bit microprocessor and it is logical extension of the 80236.
2	It has pipelined architecture (not highly) and high speed bus interface on single chip.	It is highly pipelined architecture and much faster speed bus than 8086.
3	It is upward compatible with 80386.It means all 8086 instructions are followed by 80386.	However, 80386 can support 8086 programming model & can also directly run the programs  written for 8086 in virtual mode if VM=1(in protected mode)
4	It is housed on a 40 pin  DIP package.	The chip of 80836 contains 132 pins.
5	It is a built on a HMOS technology.	The 80386 using High-speed CHMOS III technology.
6	No special hardware is equipped for task Switching.	It has a  special hardware for task switching.
7	The 8086 operates on a 5MHz. Clock.	The 80386 operate 33MHz clock frequency maximum.
8	The address bus and data bus are multiplexed.	It has separate address and data bus for time saving.
9	It has a transistor package density of 29,500 transistors.	Transistor density and complexity further increases 2,75,000.
10	It has a total of 117 instructions.	It has total 129 instructions
11	It has no mechanism protection, paging.	The 80386  contains protection mechanism paging which has instruction two support them
12	It is operated in one mode only.	It operate in three modes a)Real b)Virtual c)Protected
13	It has only instruction Queue.	It has instruction Queue as well as pre fetch queue.
14	In 8086, It is not necessity that all operation are in parallel mode.	80386 all functional units are not parallel
15	8086 has nine flags.	It contains all nine flags of 8086 but other flags named IOP,NT,RF,VM.

  Comparison between 8086 and 8088 Microprocessors

S.No.	8086 Microprocessor	8088 Microprocessor
1	The instruction Queue is 6 byte long.	The instruction Queue is 4 byte long.
2	In 8086 memory divides into two banks, up to 1,048,576 bytes.	The memory in 8088 does not divide in to two banks as 8086.
3	The data bus of 8086 is 16-bit wide	The data bus of 8088 is 8-bit wide.
4	It has BHE( bar ) signal on pin no. 34 & there is no SSO(bar) signal.	It does not has BHE( bar ) signal on pin no. 34 & has only SSO(bar) signal. It has no S7 pin.
5	The output signal is used to select memory or I/O at M/IO(bar) but if IO(bar)/M low or logic ‘0’ it selects I/O devices and if IO(bar)/M is high or logic ‘1’it selects memory.	The output signal is used to select memory or I/O at M(bar)/IO but if IO/M(bar) is low or at logic ‘0’,it selects Memory devices and if IO/M(bar) is high or at logic ‘1’it selects I/O.
6	It needs one machine cycle to R/W signal if it is at even location otherwise it needs two.	It needs one machine cycle to R/W signal if it is at even location otherwise it needs two.
7	In 8086, all address & data Buses are multiplexed.	In 8088, address bus, AD7- AD0 buses are multiplexed.
8	It needs two IC 74343 for de-multiplexing AD0-AD19.	It needs one IC 74343 for de-multiplexing AD0-AD7.

 

9	8086 is available in 3 clock speed 5 MHZ,8MHZ and 10MHZ.	8088 is available in 2 clock speed 5 MHZ and 8MHZ.
10	The I/O voltage level for 8086 is measured at 2.5 mA.	In 8088,the I/O voltage level is measured at 2 mA.
11	It draws maximum suuply current of 360mA.	It draws maximum suuply current of 340mA.