My first computer was a DEC PDP-11/70. The PDP-11 line of computers was state of the art back in the 70's and early 80's. We used them for everything from machine control to image processing. They were 16 bit machines with a maximum of 4 megabytes of memory. A 300 megabyte disk drive was the size of a washing machine! Back then I programmed in assembly language, FORTRAN, and C. (Yes, C had been use even back then!) Occasionally we would even have to develop machine language programs and enter them on the switch panel on the front of the computer. Working with both hardware and software on this computer taught me a lot about general systems architecture.