I am a retired Telecommunications Engineer.

When I was at university the Electrical Engineering Department had an IBM Mainframe with a massive 1MB of memory. I almost got to use a PDP8 for my Masters project until the funding dried up.

In the early 1970s I started to design my own computer but abandoned it halfway when microprocessors were invented. I built my own (actually several) based on the 2650, and wrote my own DOS, Assembler, Basic Interpreter, Word Processor and Forth Compiler which I sold (with a partner) under the brand MicroByte.