Inside the vintage 74181 ALU chip

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https://www.electronics-lab.com/inside-vintage-74181-alu-chip/

Ken Shirriff writes: The 74181 ALU (arithmetic/logic unit) chip powered many of the minicomputers of the 1970s: it provided fast 4-bit arithmetic and logic functions, and could be combined to handle larger words, making it a key part of many CPUs. Inside the vintage 74181 ALU chip – [Link]

Reverse-engineering the ALU of 8008 microprocessor

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https://www.electronics-lab.com/reverse-engineering-alu-8008-microprocessor/

Ken Shirriff has written an article on reverse engineering the ALU of the 8008 microprocessor: A computer’s arithmetic-logic unit (ALU) is the heart of the processor, performing arithmetic and logic operations on data. If you’ve studied digital logic, you’ve probably learned how to combine simple binary adder circuits to build an ALU. However, the 8008’s […]

Inside the 74181 ALU chip: die photos and reverse engineering

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https://www.electronics-lab.com/inside-74181-alu-chip-die-photos-reverse-engineering/

A detailed die photos and reverse engineering of the 74181 ALU chip by Ken Shirriff: What’s inside a TTL chip? To find out, I opened up a 74181 ALU chip, took high-resolution die photos, and reverse-engineered the chip.1 Inside I found several types of gates, implemented with interesting circuitry and unusual transistors. The 74181 was a […]

Inside the ALU of the first ARM microprocessor

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https://www.electronics-lab.com/inside-the-alu-of-the-first-arm-microprocessor/

Dave @ daveshacks.blogspot.co.uk takes a look inside the first ARM microprocessor and explains it’s design. With that in mind I embarked on my own attempt to reverse-engineer parts of the armv1. Some background knowledge of the processor’s architecture is helpful, and googling for “ARM Architecture Reference Manual” will lead you to very detailed descriptions of […]