Collaborate Disseminate
[Ken] recently obtained an attitude indicator—sometimes called an artificial horizon—from an F-4 fighter jet. Unlike some indicators, the F-4’s can rotate to show pitch, roll, and yaw, so it moves …read more Continue reading Inside the F-4 Attitude Indicator
The 80386 was — arguably — Intel’s first modern CPU. The 8086 was commercially successful, but the paged memory model was stifling. The 80286 also had a protected mode, which …read more Continue reading [Ken] Looks at the 386
[Ken Shirriff] is looking inside chips again. This time, the subject is the MK4116 — a 16 Kbit DRAM chip. Even without a calculator, you know that’s a whopping 2 …read more Continue reading 16 Kbit DRAM Gives Up Its Secrets
Video gamers know about cheat codes, but assembly language programmers are often in search of undocumented instructions. One way to find them is to map out all of a CPU’s …read more Continue reading Finding Undocumented 8086 Instructions Via Microcode
One of the interesting features of the 8086 back in 1978 was the provision for “string” instructions. These took the form of prefixes that would repeat the next instruction a …read more Continue reading String Operations the Hard(ware) Way
Few CPUs have had the long-lasting influence that the 8086 did. It is hard to believe that when your modern desktop computer boots, it probably thinks it is an 8086 …read more Continue reading Silicon Sleuthing: Finding a ancient bugfix on the 8086
Texas Instruments isn’t the name you usually hear associated with the first microprocessor. But the TI TMX 1795 was an 8008 chip produced months before the 8008. It was never …read more Continue reading Exploring Texas Instrument’s Forgotten CPU
A good chip decapping and reverse engineering is always going to capture our interest, and when it comes from [Ken Shirriff] we know it’s going to be a particularly good …read more Continue reading The MOS 7600 Video Game Chip Gives Up Its Secrets
Despite what it looks like in the movies, it is hard to communicate with astronauts from Earth. There are delays, and space vehicles don’t usually have a lot of excess …read more Continue reading Can You Hear Me Now? Lunar Edition
If you haven’t seen [Ken Shirriff]’s teardowns and reverse engineering expeditions, then you’re in for a treat. His explanation and demonstration of the Apollo digital ranging system is a fascinating …read more Continue reading The Apollo Digital Ranging System: More Than Meets The Eye