What was the name of the first operating system on IBM PC?

Answer 1

DOS: Disk Operating System

TOS: Tape Operating System, most likely came first.

It used 1/2 inch 7 channel tapes on computers without harddisks.

Before that IBM had a system called IBSYS on their 7090 & 7094 computers, but it was more of a Batch Monitor than a real Operating System (it only automatically ran jobs one after another in batches).

Answer 2

The first Apple computer (the Apple 1 made in 1976) did not have an operating system, as was common with small computers at the time, but it did have a System Monitor which provided a command line for the user to view memory contents, type and run programs.

The System Monitor was expanded into a simple operating system for the Apple II initially stored in a ROM on the motherboard. With the gradual introduction of disk drives Apple expanded the OS into a Disk Operating System called Apple DOS which first appeared in 1978.

The Apple DOS evolved through numerous revisions. Apple went on to develop graphical user interfaces initially for their Lisa computer which was known as the Lisa Office System (OS) and then for the Macintosh. The first Macintosh operating system was known as System 1. It evolved up to System 7 and acquired the name Mac OS with the release of Mac OS 7.6 in 1997.

Answer 3

the name of the first operating system on IBM PC is DOS.