Monthly Archives: April 2026

Learn Something Old Every Day, Part XX: 8087 Emulation on 8086 Systems

Posted on April 24, 2026 by Michal Necasek

Not too long ago I had a need and an opportunity to re-acquaint myself with the mechanism used for software emulation of the 8087 FPU on 8086/8088 machines. As mentioned elsewhere, the 8086 CPU (1978) had a generic co-processor interface … Continue reading →

Posted in 8086/8088, Development, Intel, LSOED, Microsoft, x87 | 20 Comments

Learn Something Old Every Day, Part XIX: Athlon XP May Be Athlon MP

Posted on April 20, 2026 by Michal Necasek

Quite a while ago, I acquired a dual-socket (Socket 462 aka Socket A) board for the Athlon MP, AMD’s first entry into the multi-processor/multi-socket market. Over the course of several years, I spent quite some time searching for the board … Continue reading →

Posted in AMD, K7, LSOED, PC hardware, PC history | 8 Comments

Mystery CPUID Bit

Posted on April 17, 2026 by Michal Necasek

Yesterday I had the opportunity to test a recently acquired Athlon 1200 CPU (Thunderbird core, ceramic PGA package). I dreaded the first boot-up attempt because I have had rather bad experience with slightly newer Palomino and Thoroughbred OPGA processors—a surprisingly … Continue reading →

Posted in AMD, K7, PC hardware, Undocumented | 20 Comments