 Hello everyone, this is Vaishwana Chavan, Assistant Professor, Computer Science and Engineering Department, Valchan Institute of Technology, Solapur. Now I am here to explain the differences between the MicroBusers 8085 and 8086. At the end of this session, the students will be able to differentiate the 8085 and 8086 architecture. Let us see the how MicroBusers age, initially in the year 1971, 4004, MicroBusers is introduced, whose data size is 4 and memory size 4096, later on in 73, 8008 is introduced, whose data size is 8 and supports for memory size 14 kb. Then in the same year, two more 8008 MC6800 are introduced with 8 bit and 64 kb and later on in 1977 MicroBusers 8085 is introduced. It has 8 bit data bus and it supports for 64 kb of memory. Then in the next year, 1978, 8086 is introduced, whose data size is 16 bit and it supports for 1 MB of memory. And in 1979 8088 is introduced, whose data size is 16 bit and supports for 1 MB of memory. And in 1983 80286 is introduced, data size 16 and memory size 16 MB, in 8680386 is introduced and in 8980486 is introduced, in 93 Pentium is introduced, so all these three are having data size 32 bit and memory size 4 GB. And in 93 Pentium is introduced, 32 bit data, 4 GB of memory and in 95 Pentium Pro and data size is 64 and 64 GB memory is supported. So this is about the microprocessor H, now you will see more detail about differences between 85 and 86 microprocessor. The first point regarding architecture, now 8085 supports as a risk, reduce instruction set computer and 8086 is a sysc, complex instruction set computer, you will see more detail after this slide. Second point regarding pipeline, 85 does not support for pipeline concept but 8086 supports for pipeline concept. So regarding data bus, microprocessor 85 has 8 bit data bus and 86 has 16 bit. Regarding address bus, 8085 supports 16 bit address bus and 8086 supports for 20 bit address bus. And regarding memory, it supports for 64 KB and it supports for 1 MB. Then next point regarding instruction queue, so it does not have but 86 it has instruction queue whose length is 6 bytes. So regarding next point multiprocessing, 85 does not support for multiprocessing concept but 86 supports for multiprocessing concept. So regarding flags, 85 supports 5 different flags and 86 supports 9 different flags. The next point regarding input output, so 8085 supports for 256 IO devices since it has 8 bit data lines 2 raise to 8 256 and this is having 16 data lines and 20 address lines. It supports for 6 5 5 3 6 different IO devices. Next point regarding arithmetic support, it supports for integer and decimal. It supports for integer decimal and ASCII. Next multiplication and division, so 85 does not have multiplication and division instructions. It performs multiplication by successive addition and division by successive subtraction. But 86 supports for multiplication and division instructions. Next regarding operating modes, it operates in single mode but 8086 operates in 2 different modes minimum and maximum mode. Now regarding external hardware, 85 requires less external hardware while 86 requires more external hardware. Next regarding cost, 85 is available at low cost, 86 is available at high cost. Next point regarding segmentation, so it does not support for segmentation but 86 supports for segmentation. There are 4 different segmentations, core segment, data segment, extra segment and stack segment. Now we will see more detail regarding differences. Now CISC stands complex instruction set computer, so 8086 supports for CISC. Now it refers to number of complexity of instructions. The improvement was done with respect to 85, it supports for multiply and divide instruction. The number of instructions increased from 25 which is about 4004 processor to 246 which is of 8085 and 20000 which is with respect to 86 or 8080 microprocessor. Now a risk, it stands reduced instruction set computer. So 8085 falls under this to execute one instruction per clock since it does not support for pipeline concept. Think about this question and try to write the answer. The question is how many data and address lines are present in 8085 and 8086. Pause this video and write down the answer. I hope you have answered. The answer is 8085 supports 8 data lines and 16 address lines and 8086 supports 16 data lines and 20 address lines. So next concept regarding pipeline, so there are 2 ways to make CPU processor information make faster. The first one is increasing the working frequency and second one is change the internal architecture of CPU itself. Now the pipelining is to allow CPU to fetch and execute at the same time. We will see with example. So this is non-pipelined microprocessor that is 8085. Since it is not a non-pipelined processor it fetches in first clock cycle next it executes. So it requires 2 cycles to fetch and execute the first instruction similarly for second fetch and execute. But the pipeline processor which is 8086 which fetches the first instruction in first clock cycle in second clock cycle it executes meanwhile during second clock cycle it fetches second instruction. It does not happen in non-pipelined. Similarly in third clock cycle it executes second and it fetches third instruction. So at the end of fourth clock cycle so execution of third instruction is available. Regarding registers so 85 has 8 bit registers like A, B, C, D, H, L but 8 bit registers in 86 are like A, H, L, B, H, B, L, C, H, C, L, D, H, D, L but by having a combination of A, H and L which leads 16 bit register in 86 as A, X similarly B, X, C, X, D, X, S, P, B, P, S, I, D, I. And in higher version microprocessor we will find 32 bit registers which are extended as EAX, EBX, ECX, EDX, ESP, E, BP, ESI, EDI. So these are the references thank you.