[HN Gopher] Counting the transistors in the 8086 processor: it's... ___________________________________________________________________ Counting the transistors in the 8086 processor: it's harder than you might think Author : zdw Score : 109 points Date : 2023-01-14 18:42 UTC (4 hours ago) (HTM) web link (www.righto.com) (TXT) w3m dump (www.righto.com) | psacawa wrote: | Very interesting. | | Anyone has any idea about the technology that could be used for | imaging more dense ICs and multilayer PCBs? In a presentation | elsewhere, Ken says that he used a metallurgical telescope and | USB microscope. So the imaging is done with visible light and | limited resolution. It is enough for old chips, e.g. the 8086 | discussed in this article is made with a 3um process. | | As I look around I see recent Intel chips haven't been reversed. | [0] There are allusions to x-ray tomography and electron | microscopes [1]. Anyway a plebs can get close for cheap? | | [0] | https://reverseengineering.stackexchange.com/questions/5878/... | | [1] https://www.youtube.com/watch?v=WOZqoTuAGKY | kens wrote: | There's a reason I mostly stick to chips from the 1970s. | Moore's law makes reverse engineering (literally) exponentially | harder for later chips. Multiple layers of metal on the make it | much more difficult; you can remove layer-by-layer but it's | very hard. An electron microscope helps, and you can get one | for semi-hobbyist prices if you try. X-ray tomography looks | like a cool technology but it is very cutting edge and | extremely expensive. See: https://spectrum.ieee.org/chip-x-ray | klelatti wrote: | Another great post from Ken - thanks again for all your work. | | Looking at the transistor / vacancy counts for microcode it | struck me just how this reduces the count of those used for logic | in the rest of the CPU - down to less than 12,000 I think. [1] | | The 8086's competitor the Z8000 had c17,500 and didn't use | microcode so must have been significantly more complex to design | - so giving Intel the advantage in getting to market first. | | [1] This ignores the transistors used for registers etc. | neonate wrote: | http://web.archive.org/web/20230114190129/http://www.righto.... | kens wrote: | Author here, if anyone has questions about the 8086. | diffuse_l wrote: | In the enlarged photo of the ROM transistors, the transistor in | the third row, second column, seems like it should be marked as | disconnected. | | Should it? Or is there something I'm missing in the way the | transistors are connected? | kens wrote: | Oops, yes you are correct. Now I need to fix my diagram :( | kragen wrote: | i don't have any questions but i do have a lot of appreciation | | thank you for writing this series | kens wrote: | Thanks! It's nice to know that people are finding it | interesting. | [deleted] | java-man wrote: | Always an informative read, thank you so much, Ken! | metadat wrote: | How did you actually count the transistors? Was it a completely | maddening manual process or did you develop a tool or other | approach to reduce toil and preserve sanity? | kens wrote: | I traced out the layers of the chip using GIMP, which was | tedious and took several days. I have a super-hacky program | that extracts transistors from these layers, figures out | connectivity, and generates gates from the transistors. So I | didn't need to count the transistors one-by-one, but I did | need to trace out each one. | bit-hack wrote: | You mention that you have traced out every transistor from die | photos, and I was wondering how much work there would be to | make a netlist for the 8086 like that which was used to produce | the visual 6502 simulator? | | It that feasable or is there lots of work to do to get to that | stage? | | I'm loving your series on the 8086 btw :) | kens wrote: | I'm working on a simulator :-) | tpmx wrote: | (That sounds brilliant!) | | Using an HDL like Verilog or VHDL? Something else? | kens wrote: | I'm planning on a visual6502-style simulator in a | browser. | bit-hack wrote: | Oh fantastic! this makes me super happy to hear :) I'd love | to play with it. | dtgriscom wrote: | Off-topic: how do you you find out that your site has been | mentioned on Hacker News? Do you notice a surge in traffic? Do | you check Hacker News periodically? Did you feel a disturbance | in the force? | kens wrote: | I use f5bot.com, a free service that checks Reddit, Hacker | News, and Lobsters for keywords. | netr0ute wrote: | Is it true that lots of embedded system today still use a 8086 | of some kind, because they're really cheap/easy to understand? | kens wrote: | I think the Intel 8051 is still used in embedded systems. I | don't know about the 8086 but it wouldn't surprise me. | wildzzz wrote: | 8051 is the basis for many microcontrollers today. They | aren't compatible since vendors add all kinds of custom | instructions or modifications to the original design but | some vendors do still make drop in replacements. You can | also get soft core versions for FPGAs that can run original | software. | forinti wrote: | If they are still manufactured, which process is used? | | I guess even a 65nm 8086 would be tiny. | BirAdam wrote: | Production of the 8086 by Intel stopped in 1998. I imagine | that it may have continued by another manufacturer, but I | doubt it. 8051 descendants/derivatives are manufactured, | but no longer by Intel. | | In general ARM and RISC-V have taken much of the low end | market and microcontroller market. | anticensor wrote: | And lightning fast. | fijiaarone wrote: | This is what happens tv becomes unwatchable. ___________________________________________________________________ (page generated 2023-01-14 23:00 UTC)