The software with the worst sales in Microsoft products is 'OS / 2 for the Mach 20'

Computer History Museum/Gift of Douglas Flock

Microsoft sells a lot of software such as OS 'Windows' and office suite 'Microsoft Office'. Raymond Chen,

In the mid-1980s, Microsoft produced an expansion card 'Mach 10' for the IBM PC and IBM PC XT. Mach 10 is equipped with a 9.54 MHz 8086 CPU, and by removing the onboard 8088 CPU (4.77 MHz) and installing it in an empty socket, we were able to double the performance of the IBM PC. It also had a mouse port, so I could connect a mouse without adding an expansion slot, but unfortunately it was a failure.

Still, Microsoft produced 'Mach 20' in 1987 without being discouraged. The basic idea was the same as 'Mach 10', and it was equipped with an 8MHz 80286 CPU. In addition, it was equipped with an expansion slot for the 80287 floating point coprocessor and a daughter board for high-speed RAM and floppy drive. Originally, the IBM PC had five expansion slots, but it was filled with hard drive controllers, floppy drive controllers, video cards, printer parallel ports, and mice, so it was important to be able to expand without consuming PC slots. It was the point.

A Microsoft Mach 20! This is a weirdly designed card, it's like 3 cards in one!
It's an 8mhz 286 add-on for the original IBM PC/XT, plus add-on RAM (in this configuration) https://t.co/mTkZ0mUx80 pic.twitter.com/2dRzhG285b

— foone????️‍⚧️ (@Foone) January 10, 2018

Even if the IBM PC AT, the next generation of the IBM PC and IBM PC XT, has already appeared, the reason why the previous generation machines were expanded and supported was simply that 'IBM PC AT is better than introducing a new IBM PC AT.・One is that it is cheaper to expand the IBM PC XT. At that time, the depreciation period for computers was seven years, so new models could not be introduced so often. is. In addition, since the cost of the upgrade card is low, it seems that it was an advantage that it could be secretly included in the office equipment budget.

According to Mr. Chen, Mach 20 sold better than Mach 10.

And Microsoft sold OS/2 customized for Mach 20, 'OS/2 for Mach 20'. However, there were major performance issues, and according to support specialists at the time, only 11 units were sold. 8 were returned, so there were only 3 customers. The support specialist seems to have contacted two of them.

If those numbers are accurate, Chen says he thinks OS/2 for Mach 20 is a contender for the worst-selling Microsoft software ever shipped.

By the way, I do not know what kind of user the remaining one who purchased 'OS / 2 for Mach 20' is.

In Hacker News, johnhattan commented that he touched 'OS / 2 for Mach 20' when he was doing Microsoft product support at Texas A & M University as a side job. According to johanhattan, he had the opportunity to upgrade a large number of old IBM PC XTs, and although DOS and Windows 286 worked, 'OS / 2 for Mach 20' did not finish installing no matter what. Mr. johnhattan reported this to his boss, and after a while his boss told Mr. johnhatta, ``Because it was treated as a non-functional product, it will soon disappear.''

Oooh I remember having one of these (with OS/2, no less) back when I had a side-... | Hacker News
https://news.ycombinator.com/item?id=34139142