Intel Snap In 386sx Retail Box Upgrade Internal

Intel’s SnapIn 386 upgrade allows users to upgrade an IBM PS/2 Model 30 from a 286 to a 386SX-based architecture. Once installed, it will allow the computer to run 386-based applications.

The idea behind it was (partly) to give Intel a way away from selling 80286 range CPUs, and (partly) to give PS/2 users an upgrade for their very, very expensive investment. Finally, it allowed Intel to sell 2x CPUs for at least some of the PCs that shipped.

By the late 80s Intel had been forced by IBM to allow several quite formidable rival foundries to ‘second source’ the 8088, 8086 and 80286 CPUs that shipped in the original PC, PCXT and PCAT plus compatibles. The 80286 was worth around $30 thanks to the magic of competition, with Harris in particular releasing a 20 and 25Mhz 80286 when Intel stopped at 12Mhz. The 25mhz 80286 had to be seen to be believed. Intel was still selling the 80386 original device at between 16 and 33Mhz, with no competition, at around $900 for the top flight device (and we thought we had it bad!). Andy Grove, the man in charge at Intel decided that the time had come to stop second source deals at the 80286, and so decided the defend the 32 bit 80386 leviathan with every and all legal means at Intel’s disposal. And defend they did – keeping AMD mainly out of the 80386 market quite successfully for several years tied up in court whilst arguing over the rights to Intel’s microcode. Whilst they were at it, arguing over the definition of microcode, if it can be subject to copywrite law and on and on…. A very successful tactic when the aim of the game is simply time. Keep your rivals out of the market for as long as possible, whilst starving them of the real ‘cream’ profits from the top flight devices.

The 80386sx (a simplified 16bit version) was the 2nd pincer upon the 2nd source suppliers who were being kept out of the 80386 market. It made absolute sense to shut down the 286 market as rapidly as possible by replacing with a cheap ‘386 device that could run Windows 3.0 (which the 286 couldn’t really). In the real world, the 80386sx (especially at low clockspeeds, like 16Mhz) wasn’t noticeably better or faster than the top flight 80286 CPUs.