Tech Nostalgia: A Computer Needs an OS Like a Fish Needs a Bicycle (Premium)

The first personal and home computers booted into a ROM, or read-only memory, that usually consisted solely of an on-chip BASIC interpreter, typically made by Microsoft. That was minimally acceptable for the software developers and other enthusiasts and early adopters who constituted the market for these devices in the 1970s. But for personal computing to enter the mainstream, these machines would need to become more sophisticated and more useful. And both of those attributes would be achieved largely through software, not hardware.

The more powerful mainframes and minicomputers of the day used so-called operating system (OS) software like Unix or TOPS-10 that ran at boot time and acted as an intermediary between the software programs that users ran and the underlying hardware. These OSes handled input and output, processor, RAM, and other resources, and provided common services so that programs--what we call apps today--didn't have to recreate each individually. In that day, of course, user interfaces were minimal and entirely text-based, and so they were still relatively unfriendly and unsuitable for mainstream users.

By the late 1970s, Microsoft's Bill Gates saw the need for a similar "standard OS" for personal computers. His company quickly found itself supporting multiple incompatible microprocessor architectures--from the Intel 808x series to the MOS 6502 to the Motorola 6800 and more--and a coming generation of 16-bit chips would provide even more powerful hardware for even more advanced computers. Standardization would help easy the difficulty and time it took to port programming languages and programs between these machines.

"Software houses would write programs to run under the standard OS and wouldn't have to worry about multiple versions," he wrote in his column in Personal Computing in 1977.

Today, it seems obvious that Microsoft would tackle this problem. But Gates had no plans to make an OS when he wrote those words. He didn't see the need: Gary Kildall had already created an OS for 8-bit microcomputers called CP/M--Control Program/Monitor, later the slightly less terrible Control Program for Microcomputers--that focused on file storage. This so-called disk operating system, or DOS, originally targeted the same Intel 8080 processor that inspired the creation of Microsoft, but it quickly spread to other architectures like the Zilog Z80. Indeed, it was so popular with Intel- and Z80-based computers that Microsoft created its first-ever hardware product, the Z80 Soft Card, in 1980 so that users of the incompatible 6502-based Apple II line could access the then-vast CP/M software library.

As a DOS, CP/M managed file storage and organization, sparing app developers from having to write the code to do so themselves. It also provided a software environment in which programming languages more sophisticated than Microsoft's interpreted BASIC could run, enabling them to create ever-more-powerful programs. Microsoft at the...