Reverse-engineering the First FPGA Chip Xilinx XC2064

Reverse-engineering the First FPGA Chip Xilinx XC2064
by Ken Shirriff on 09-16-2020 at 6:00 am

Xilinx XC2064

A Field-Programmable Gate Array (FPGA) can implement arbitrary digital logic, anything from a microprocessor to a video generator or crypto miner. An FPGA consists of many logic blocks, each typically consisting of a flip flop and a logic function, along with a routing network that connects the logic blocks. What makes an FPGA… Read More


Inside the HP Nanoprocessor: A High-speed Processor That Can’t Even Add

Inside the HP Nanoprocessor: A High-speed Processor That Can’t Even Add
by Ken Shirriff on 09-06-2020 at 10:00 am

Inside the HP Nanoprocessor

The Nanoprocessor is a mostly-forgotten processor developed by Hewlett-Packard in 19741 as a microcontroller2 for their products. Strangely, this processor couldn’t even add or subtract,3 probably why it was called a nanoprocessor and not a microprocessor. Despite this limitation, the Nanoprocessor powered numerous… Read More


Inside a Counterfeit 8086 Processor

Inside a Counterfeit 8086 Processor
by Ken Shirriff on 08-19-2020 at 2:00 pm

Fake Intel 8086 CPU

Intel introduced the 8086 processor in 1978, leading to the x86 architecture in use today. I’m currently reverse-engineering the circuitry of the 8086 so I’ve been purchasing vintage 8086 chips off eBay. One chip I received is shown below. From the outside, it looks like a typical Intel 8086.

The package of the fake
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Die shrink: How Intel scaled down the 8086 processor

Die shrink: How Intel scaled down the 8086 processor
by Ken Shirriff on 07-22-2020 at 2:00 pm

Intel 8086 Comparison

The revolutionary Intel 8086 microprocessor was introduced 42 years ago this month so I’ve been studying its die.1 I came across two 8086 dies with different sizes, which reveal details of how a die shrink works. The concept of a die shrink is that as technology improved, a manufacturer could shrink the silicon die, reducing… Read More


A Look at the Die of the 8086 Processor

A Look at the Die of the 8086 Processor
by Ken Shirriff on 07-15-2020 at 6:00 am

Intel 8086 Die

The Intel 8086 microprocessor was introduced 42 years ago last month,1 so I made some high-res die photos of the chip to celebrate. The 8086 is one of the most influential chips ever created; it started the x86 architecture that still dominates desktop and server computing today. By looking at the chip’s silicon, we can see… Read More