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Comment by Taniwha | Hacker News Reader

remember that the address and data pins are multiplexed - the 8088 and 8086 have the same number of pins

My guess is that the prefetch buffer is always 6 bytes but the 8088 fetches instructions more slowly and never fills it past 4 instructions

I think they're probably the same die, the thing to look for is whether there's a bonding difference

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> I think they're probably the same die

Very unlikely. The 8088 was developed after the 8086, and there are more pin differences including m/io inverting to io/m.

Now I really want to get a 8086 on a bread board and see if I can do things with it! What else do I need to put on the breadboard to build a minimum computer?

Probably just a voltage regulator, a clock source, reset pin logic, a couple ROM chips (2 8-bit wide chips or 1 16-bit wide), some static RAM, a PAL/GAL/74xx logic for address decoding and chip select pins, stuff to deal with the multiplexing, and whatever input/output you want (bus buffers for parallel I/O, off the shelf UART chips, etc)

I’ve only done it with the 6502 and Z80, but the 8086 shouldn’t be too much harder. There are plenty of resources available online for those two chips that you could adapt!

http://www.malinov.com/Home/sergeys-projects/xi-8088

http://tech.mattmillman.com/projects/8od/

http://www.s100computers.com/My System Pages/8086 Board/8086 CPU Board.htm

In minimum mode you don't need more than a ROM, SRAM, and clock source.

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