In 1979, Intel introduced the 8088 microprocessor, a variant of the 16-bit 8086 processor. IBM's decision to use the 8088 processor in the IBM PC (1981) was a critical point in computer history, ...
What would you say is the first microcomputer?1 The Apple I from 1976? The Altair 8800 from 1974? Perhaps the lesser-known Micral N (1973) or Q1 (1972)? How about the Arma Micro Computer from ...
http://www.righto.com/2024/02/the-first-microcomputer-transfluxor.html
The Bendix Central Air Data Computer (CADC) is an electromechanical analog computer that uses gears and cams for its mathematics. It was a key part of military planes such as the F-101 and the F-...
http://www.righto.com/2024/02/bendix-cadc-servomotor-tachometer.html
In the 1950s, many fighter planes used the Bendix Central Air Data Computer (CADC) to compute airspeed, Mach number, and other "air data". The CADC is an analog computer, using tiny gears and spe...
http://www.righto.com/2024/02/reverse-engineering-analog-bendix-air.html
The 386 processor (1985) was Intel's most complex processor at the time, with 285,000 transistors. Intel had scheduled 50 person-years to design the processor, but it was falling behind schedule....
I recently came across an interesting die photo of a Soviet1 chip, probably designed in the 1970s. This article provides an introductory guide to reverse-engineering CMOS circuits, using this ch...
The Bendix Central Air Data Computer (CADC) is an electromechanical analog computer that uses gears and cams for its mathematics. It was a key part of military planes such as the F-101 and the F-...
http://www.righto.com/2024/01/bendix-cadc-pressure-transducers.html
I've studied a lot of chips from the 1970s and 1980s, so I usually know what to expect. But an Ethernet chip from 1982 had something new: a strange layer of yellow wiring on the die. After some s...
http://www.righto.com/2023/12/amd-lance-ethernet-double-poly.html
While repairing an eight-inch HP floppy drive, we found that the problem was a broken interface chip. Since the chip was bad, I decapped it and took photos. This chip is very unusual: instead of ...
http://www.righto.com/2023/12/HP-silicon-on-sapphire-phi-chip.html
Intel's 386 processor (1985) was an important advance in the x86 architecture, not only moving to a 32-bit processor but also switching to a CMOS implementation. I've been reverse-engineering par...
The Intel 386 processor (1985) was a large step from the 286 processor, moving x86 to a 32-bit architecture. The 386 also dramatically improved the performance of shift and rotate operations by a...
Processors are driven by a clock, which controls the timing of each step inside the chip. In this blog post, I'll examine the clock-generation circuitry inside the Intel 386 processor. Earlier pr...
The groundbreaking Intel 386 processor (1985) was the first 32-bit processor in the x86 line. It has numerous internal registers: general-purpose registers, index registers, segment selectors, an...
http://www.righto.com/2023/11/reverse-engineering-intel-386.html
Introduced in 1973, Ethernet is the predominant way of wiring computers together. Chips were soon introduced to handle the low-level aspects of Ethernet: converting data packets into bits, implem...
http://www.righto.com/2023/10/reverse-engineering-ethernet-backoff-on.html
You might think of the Intel 386 processor (1985) as just an early processor in the x86 line, but the 386 was a critical turning point for modern computing in several ways.1 First, the 386 moved...
How did fighter planes in the 1950s perform calculations before compact digital computers were available? The Bendix Central Air Data Computer (CADC) is an electromechanical analog computer that ...
http://www.righto.com/2023/10/bendix-cadc-reverse-engineering.html
A key concept for a processor is the management of "state", information that persists over time. Much of a computer is built from logic gates, such as NAND or NOR gates, but logic gates have no n...
The Intel 8086 processor started the x86 architecture that is still extensively used today. The 8086 has some quirky characteristics: it is little-endian, has a parity flag, and uses explicit I/O...
The Intel 8086 microprocessor (1978) revolutionized computing by founding the x86 architecture that continues to this day. One of the lesser-known features of the 8086 is the "hold" functionality...
What happens if you give the Intel 8086 processor an instruction that doesn't exist? A modern microprocessor (80186 and later) will generate an exception, indicating that an illegal instruction w...
http://www.righto.com/2023/07/undocumented-8086-instructions.html
The Intel 8086 microprocessor (1978) started the x86 architecture that continues to this day. In this blog post, I'm focusing on a small part of the chip: the address and data pins that connect t...
The Intel i960 was a remarkable 32-bit processor of the 1990s with a confusing set of versions. Although it is now mostly forgotten (outside the many people who used it as an embedded processor),...
http://www.righto.com/2023/07/the-complex-history-of-intel-i960-risc.html
A key component of any processor is instruction decoding: analyzing a numeric opcode and figuring out what actions need to be taken. The Intel 8086 processor (1978) has a complex instruction set,...
http://www.righto.com/2023/05/8086-processor-group-decode-rom.html
While programmers today take division for granted, most microprocessors in the 1970s could only add and subtract — division required a slow and tedious loop implemented in assembly code. One of...
http://www.righto.com/2023/04/reverse-engineering-8086-divide-microcode.html
Intel introduced the 8086 microprocessor in 1978. This processor ended up being hugely influential, setting the path for the x86 architecture that is extensively used today. One interesting featu...
http://www.righto.com/2023/04/8086-microcode-string-operations.html