When the TC based micro processors came into the field, there used to be an IC/M processor. This was very difficult to use. Then came the CP/M microprocessors. Tim Patterson invented an operating sytem known as Q-DOS, which is an acroynm of Quick and Dirty Operating System. Later on this was modified as 86-DOS and 88-DOS because it was then used 8086 and 8088 microporcessors. The then richest software company purchased the rights of 88-DOS and renamed it as MS-DOS. (Microsoft Disk Operating System).