DOS

DOS is really an acronym for Disk Operating System. In reallty there were many varations but had names like MSDOS, DR-DOS, PC-DOS etc. DOS pretty much dominated the PC market between 1981 and 1995.

They were designed to run on the Intel 8080 and Z80 based microcomputers. Later versions ran on the Intel 80x86-family processors.

Today DOS is still finding some limited life, mainly as specialized purposes. A while back, I made a counter for a client that needed a display that he could see from a distance. As he spoke to an audience he could see through recording room's window a 20 inch computer monitor that was displaying how long the recording had been going. The recording was later broadcast on the radio and he had to keep it under 30 minutes. As he spoke, the numerals 00:01 would progress to 30:00 and slowly shift from green to red. All this was done on a little 386sx running DOS.

Another use that DOS like DR-DOS and ROM-DOS have found is the embedded market. For example the camera Canon Power ShoPro 70 used ROM-DOS.

A person can do some rudimentary programming with the command line using what is called batch files. A batch file is a plain ASIIC text file with DOS commands much like is called a script file. DOS batch files are named due to being a file with a "batch of DOS commands". A batch file can ran just by typing it's name at the command prompt and pressing [RETURN] or {ENTER].

Whenever a computer is booted with DOS, two files are accessed on bootup. The CONFIG.SYS file has a list of drivers and parameters. For example to enable a CDROM drive, the driver for the CDROM drive would be in the config.sys file. After the Config.sys file is accessed, the AUTOEXEC.BAT file is executed. It is a batch file of DOS commands to be ran. Many times the last command would be the name of a program that you would want to run automatically. In the days before Windows, the most common program would be a simple Menu program where a person could select what program he wanted to use, whether it was a word processor or a game. In the case of the Counter Appliance I made for the client I had the name of the program I had written. It was automatically ran and sat waiting for someone to press the space-bar to start the counting.