My first true IBM pc was an original 6 MHz intel 80286 CPU IBM AT.
This was a work place PC and was from the very first batch to arrive in UK before it went on public sale. I worked for UK Atomic Energy which was government owned (hence why we got first dibs).
It had a massive 640K RAM, and a 20MB hard disk. I used it to do my PHD thesis.
We managed to compile a major Fortran mainframe program on it and it was awesome to have a GUI (dos based) to run the program and get result in 30 minutes (after entering data).
Mainframes took much longer as we had to use text input files and it took ages to type them plus queues to use mainframe often meant you could only get one run per day, so you had to be very careful about typing in data correctly.
Actually the same program (I was one of early developers) is still used to this day, and is still a world market leader. It takes 1-2 seconds to do a run (after data entry).
Printers were dot matrix (graphic printers were megamegabucks). Never had to worry about filling paper trays. The box the paper came with was the tray. Noisy as hell though LOL.
If we wanted to print something graphical, we had to send print output to graphical plotters with moving pens. Each page probably cost around £1 in early 1970s. So out bosses would shoot us if we printed too many LOL.
My first ever personal computer was a 6502 cpu with keyboard and very crude display and we could only use Assembler Language (more accurately machine code).
It was awesome when we could get a single dot to move around screen and bounce around.
One of the magazine specialists I used to follow was a guy called "Bill Gates" before he produced (bought more accurately) MS DOS.