stjepanoAug 25, 2023
Ken Shirriff
I found a hidden name in the Intel 8088 processor. The 8088 was a derivative of the 8086 processor introduced in 1979 and best known as the processor in the IBM PC. I dissolved the chip's metal layer and found "רפי", the name in Hebrew of Rafi Retter, the chip's engineer.
Aug 7, 2023 at 5:08pmWeb
Show threadKen ShirriffAug 7, 2023
The 8088 is constructed from a silicon wafer with polysilicon wiring and a single metal layer on top. (Modern chips can have a dozen layers of metal.) The metal obscured the name, making it unreadable on the chip until I dissolved the metal with acid.
Show threadKen ShirriffAug 7, 2023
I haven't come across a hidden name like this before. Chip art or names on a die are usually much easier to see. Rafi Retter's initials are also in the middle of the 8088 die, much more visible since it's in the metal layer and separated from the circuitry.
Show threadKen ShirriffAug 7, 2023
The 8088 processor was designed by Intel Israel (i/IL on the die). Intel Israel also designed the Intel 8087 floating point coprocessor chip. Intel's Israel site was opened in 1974, Intel's first design and development center outside the US.
Show threadKen ShirriffAug 7, 2023
Here's a complete die photo of the 8088. The 8088 is a 16-bit chip internally but uses an 8-bit bus to reduce system cost. The chip is mostly the same as the 8086 but the bus control is redesigned, the prefetch queue is smaller, and there are minor changes throughout the chip.
Show thread⁂Krafty⁂ #NoKingsAug 7, 2023
@kenshirriff Electronics are beautiful!
Show threadSimon ZerafaAug 7, 2023

@kenshirriff

I'm sure that @SGgrc would get a kick out of this die shot 😀

Show threadmytwobits01Aug 30, 2023
@kenshirriff
How does the bus size affect the cost?
Show thread2sk21Aug 7, 2023
@kenshirriff fascinating set of photos. I didn’t realize that the Israel lab was responding for the 8088!
Show threadLaberpferdAug 7, 2023
@kenshirriff Thanks, thats interesting
Show threadshac ron ₪‎Aug 7, 2023
@kenshirriff “רפי ר”, you can see the last initial below
Show threadKevin Karhan Aug 7, 2023

@kenshirriff clever way to discourage #Copying of the #IC...

Kinda like with #Maps doing the same...
https://www.youtube.com/watch?v=DeiATy-FfjI

Why do maps show places that don't exist?

YouTube
Show threadKevin Karhan Aug 7, 2023
@kenshirriff but then again it's common for #Electronics #Designers and #Engineers to add something like a signature to their works...
https://www.youtube.com/watch?v=wzMsgnnDIRE&t=1470s
Commodore History Part 5 - The C128

YouTube
Show threadJob DestroyerAug 7, 2023

@kenshirriff

El Barto

Show threadchild of baphometAug 8, 2023
@kenshirriff Amazing.
Show threadLuis LevyAug 9, 2023
@kenshirriff Nicely done
Show threadTim HolmesAug 9, 2023
@kenshirriff How is it that you came across it initially? How did it catch your eye?
Show threadKen ShirriffAug 13, 2023
@TPOHolmes I was tracing out the circuitry on the 8088 die and saw these polysilicon lines that weren't connected to anything.