From the 1950's the way computing was done was on mainframes. These were room-sized machines, shut off to the outside world, and would cost millions. They were produced by the likes of IBM, Univac, Burroughs, Control Data, NCR, Honeywell, and others.
Let me describe how I had to use a ainframe in my first programming job.
I would think out my programs on pieces of paper, then write them out, before copying them onto specially printed sheets which I would give to a punch-card operator to type up.
When ready I would take my pack of cards and walk over to the computer centre where the mainframe computer was kept. I would type up a special header card describing the job and the resources needed by my job, and then hand over the cards to an operator who would put them into the queue of jobs to be run.
Then I would return to my office, and work on some other problem.
About an hour later I could walk back to the computer centre, and if I was lucky my cards and the line-printer output from the job would be waiting for me to pick up. I would then quickly peruse the output. If there had been a syntax error, I could correct the cards involved and resubmit the job immediately. If the job had run satisfactorily, or there was a problem that needed more thought, then I would walk back to my office.
If I was unlucky though, my job wasn't ready. I would then look at the status of the jobs to be run from a printout that was hung on the wall at regular intervals, in order to get an impression of how much longer I would have wait. Jobs that needed a minute or less of computer time got priority; if you needed more, you often had to wait a long time before your job arrived.
This was the typical life of a programmer of a mainframe computer. At least you got lots of exercise walking back and forth to the computer centre.
Starting in the 60's but picking up momentum in the 70's, a new type of computer started appearing, the minicomputer. These were more cupboard-sized machines, costing of the order of 100,000, and manufactured by the likes of DEC, Data General, Prime, and Wang. The disadvantage of these machines were that they were slower, and had few resources (memory, disk) than the mainframes. But the advantage was that they were cheap, and you could have them in the lab. You still had to share, but it was nearby, and you got instant turnround once you were on it.
Starting in the 70's but picking up momentum in the 80's came the Workstation, which could go on the desktop of the programmer in the office, and were known as 3M machines: one megapixel screen, one megabyte of memory, and costing one megacent, in other words 10,000. They were made by the likes of Sun, Xerox, Perq, Lisp Machines. Now at last programmers had machines of their own.
Starting in the 80's, came the PC, the first computer to make its way into the home. IT cost of the order of 1000, and was made by the likes of IBM, Apple, Compaq,
So we might now reasonably expect a 100 comuter. And indeed they have emerged.