Difference between 8086 and 8088 Microprocessor

By Jaxson

Main Difference

The vital qualification between the 8086 and the 8088 is that the 8086 processor had a 16-bit outer information transport and a 16-bit interior information transport, however, the 8088 processor had an 8-bit outside information transport and a 16-bit inward information transport. Another distinction between an 8088 chip and an 8086 microchip is the BIU. In the 8088, the BIU information transport way is 8 bits wide versus the 8086’s 16-bit information transport. Another distinction is that the 8088 guideline line is four bytes in length rather than six. The vital point to note, in any case, is that in light of the fact that the EU is the same for every processor, the programming directions are precisely the same for each. Programs composed for the 8086 can be keep running on the 8088 with no progressions.


It is a 16-bit microchip chip composed by Intel between mid-1976 and mid-1978 when it was discharged. The Intel 8088, discharged in 1979, was a marginally adjusted chip with an outside 8-bit information transport (permitting the utilization of less expensive and less supporting ICs, and is eminent as the processor utilized as a part of the first IBM PC outline, including the far-reaching adaptation called IBM PC XT. The 8086 offered to ascend to the x86 design which in the end turned into Intel’s best line of processors. The 8086 undertaking began in May 1976 and was initially planned as an impermanent substitute for the aspiring and deferred iAPX 432 task. It was an endeavor to draw consideration from the less-postponed 16-and 32-bit processors of different makers, (for example, Motorola, Zilog, and National Semiconductor) and in the meantime to counter the danger from the Zilog Z80 (outlined by previous Intel representatives), which turned out to be extremely fruitful. Both the engineering and the physical chip were thusly grown rather rapidly by a little gathering of individuals, and utilizing the same essential microarchitecture components and physical usage strategies as utilized for the marginally more established 8085 (and for which the 8086 additionally would work as a continuation). Promoted as source perfect, the 8086 was intended to permit low-level computing construct for the 8008, 8080, or 8085 to be consequently changed over into comparable (problematic) 8086 source code, with next to zero hand-altering. The programming model and direction set was (approximately) taking into account the 8080 keeping in mind the end goal to make this conceivable. In any case, the 8086 outline was extended to bolster full 16-bit handling, rather than the genuinely essential 16-bit abilities of the 8080/8085. New sorts of directions were included too; full backing for marked numbers, base+offset tending to, and self-rehashing operations were likened to the Z80 design, yet were all made marginally more broad in the 8086. Guidelines specifically supporting settled ALGOL-family dialects, for example, Pascal and PL/M were additionally included. As indicated by key planner Stephen P. Morse, this was an aftereffect of a more programming driven methodology than in the configuration of prior Intel processors (the originators had experience working with compiler executions). Different improvements included microcode increase and partition guidelines and a transport structure better adjusted to future coprocessors, (for example, 8087 and 8089) and multiprocessor frameworks. The principal update of the direction set and abnormal state design was prepared after around three months, and as no CAD instruments were utilized, four architects and 12 format individuals were all the while taking a shot at the chip. The 8086 took somewhat more than two years from thought to working item, which was considered fairly quick for a mind boggling outline in 1976–1978. The 8086 was sequenced utilizing a blend of irregular logic and microcode and was executed utilizing exhaustion load nMOS hardware with around 20,000 dynamic transistors (29,000 including all ROM and PLA locales). It was soon moved to another refined nMOS fabricating process called HMOS (for High execution MOS) that Intel initially created for the assembling of quick static RAM products. This was trailed by HMOS-II, HMOS-III renditions, and, inevitably, a completely static CMOS variant for battery controlled gadgets, made utilizing Intel’s CHMOS processes. The first chip measured 33 mm² and least element size was 3.2 μm.


The 8088 chip is a variation of the Intel 8086. Presented on July 1, 1979, the 8088 had an 8-bit outer information transport rather than the 16-bit transport of the 8086. The 16-bit registers and the one-megabyte address extent were unaltered, be that as it may. Actually, as per the Intel documentation, the 8086 and 8088 have the same execution unit (EU), just the transport interface unit (BIU) is distinctive. The first IBM PC depended on the 8088. All inside registers, and in addition interior and outside information transports, are 16 bits wide, which solidly settled the “16-bit chip” personality of the 8086. A 20-bit outer location transport gives a 1 MB physical location space (220 = 1,048,576). This location space is tended to by method for inside memory “division”. The information transport is multiplexed with the location transport so as to fit the majority of the control lines into a standard 40-pin double in-line bundle. It gives a 16-bit I/O address transport, supporting 64 KB of discrete I/O space. The most extreme straight delivery space is constrained to 64 KB, just in light of the fact that inward address/record registers are just 16 bits wide. Programming more than 64 KB memory limits includes modifying the section registers (see beneath); this trouble existed until the 80386 design presented more extensive (32-bit) enlists (the memory administration equipment in the 80286 did not help in such manner, as its registers are still just 16 bits wide).

Key Differences

  • The 8088 microprocessor is basically a changed version of the 8086 microprocessor.
  • The 8086 microprocessor come into existence earlier than that of the 8088 microprocessor.

Leave a Comment