Forgotten Voice

 Although many claims have been made over the years about the success of the open-source ISA technology in Personal Computer development, one crucial decision by IBM provided the impetus for PC manufacturers to shift their focus away from IBM's proprietary architecture and prioritise open-source alternatives.

Let me explain.

In 1983, I returned from an assignment in the United States and became one of the early members of IBM’s EMEA PC organisation. One of my first responsibilities was testing software on the then-unannounced Enhanced Graphics Adapter (EGA). During this work, I discovered that it did not function correctly with the “exploring” software IBM shipped with every new PC.

Soon afterward, the development team asked me to establish and lead a new function in EMEA called Compatibility Test. I ran this operation for the next 3.5 years.

By early 1986, IBM had become the dominant PC supplier, serving more than 90% of the market. On April 2, 1987, IBM announced the IBM PS/2.

Around that time, I had moved into Product Management, initially as PC printer product manager. Within weeks, however, I was reassigned to work on the PS/2.

IBM’s enormous success in the PC market had been built on openness. All physical and software interfaces were published and freely available. This allowed independent hardware and software developers to build products that leveraged the PC’s architecture. That openness fuelled innovation and growth.

With the PS/2, however, that approach changed.

The hardware architecture was innovative. Drawing on mainframe concepts, designer Chet Heath developed the Micro Channel Architecture, which differed significantly from the original ISA bus used in earlier PCs.

This is where the problems began.

A corporate decision was made to protect Micro Channel with patents. Any external vendor wishing to develop expansion cards or supporting software had to purchase expensive development toolkits containing the interface specifications. For many smaller vendors, the cost was prohibitive. Rather than adopt Micro Channel, they continued developing for ISA.

The clone market surged. Manufacturers emerged worldwide, producing ISA-based PCs while gradually evolving the standard. IBM’s market share declined, and the once-ubiquitous IBM PC became just one option among many.

The strategic decision to capitalise on the uniqueness of the PS/2 ultimately backfired. The shift away from openness accelerated the rise of clone manufacturers. Compaq was one of many companies that benefited from that shift—but it was IBM’s own strategic choices that reshaped the market and led, years later, to the sale of the PC business to Lenovo.