Both of 8085 and 8086 are two major microprocessors designed by Intel. However, the crucial difference between 8085 and 8086 microprocessors is that an 8085 microprocessor is an 8-bit microprocessor i.e., can operate on 8-bit data at a time.
As against 8086 is a 16-bit microprocessor, that can perform the operation on 16-bit data in one cycle.
There exist various other factors that create significant differences between 8085 and 8086 microprocessors. In this section, we will discuss the other differences between 8085 and 8086 microprocessors using a comparison chart.
Table of Contents
Comparison 8085 and 8086 Microprocessor
Basis for Comparison 8085 8086 Microprocessor type 8-bit 16-bit Size of data bus 8-bit 16-bit Size of address bus 16-bit 20-bit memory capacity 64 KB 1 MB Operating frequency 3 MHz 5 MHz Number of flags 5 9 Number of transistors Less (around 6500) More (around 29000) Operating mode Only one Two (minimum and maximum mode) Pipelining Unsupportable Supportable Cost Low Comparitively high Memory segmentation Unsupportable Supportable Instruction queue Absent Present Addressing mode 5 9 Clock speed The 8085 microprocessors’ clock speed is 3.072 MHz. 8086 was initially limited to 5 MHz, but it goes up to 10 MHz nowadays. Clock cycle 50% duty cycle 33%. Arithmetic Supports decimal and integer code also supports ASCII. Processor Number Only one External processor can be used
Key differences between 8085 and 8086 Microprocessor
- The size of the data bus specifies the amount of data that can be fetched by the data bus in one cycle. The size of the data bus in the case of 8085 microprocessors is 8-bit while in the case of 8086 microprocessors, it is 16-bit.
- The address bus size in the case of 8085 microprocessors is 16-bit whereas in the case of 8086 microprocessor it is of 20-bit.
- Memory addressing capacity of 8085 is 216 (i.e, 64 KB). And the contrary, the memory addressing the capacity of 8086 is 220 (i.e., 1 MB).
- 8085 operates at a frequency of 3 MHZ. Where the operating frequency of 8086 microprocessors is 5 MHz, also the advanced version of 8086 microprocessors operates at a frequency 8 and 10 MHz also.
- 8085 microprocessor consists of less number of transistors in its structure. Whereas 8086 comparatively holds a very large number of processors in it.
- 8085 supports a single mode of operation when 8086 supports two operating modes, minimum and maximum mode.
- There exist a total of 5 flags (i.e., sign, zero, auxiliary carry, parity and carry flag) in 8085 microprocessors. As against overall 9 flags (i.e., overflow, direction, interrupt, trap and rest other of 8085) are present in 8086 microprocessors.
- 8085 is a single processor configuration microprocessor. And the contrary 8086 is a multi-processor configuration microprocessor.
- Pipelining is unsupportable by 8085. Whereas pipelining is supported by the 8086 microprocessor.
- The instruction queue is absent in the 8085 microprocessor. While queuing is supported by 8086 it has an instruction queue.
- Memory segmentation is not supported by 8085 while it is supported by the 8086 microprocessor.
- 8085 is an accumulator based processor. And the contrary 8086 is a general-purpose register type microprocessor.
Due to advanced architecture and more profitable features, 8086 is more expensive than the 8086 microprocessor.