In this part of the site you will find info on the computers I owned and worked with, as well as general info about computer systems. The picture below is my first computer, the ELF II (see also this link). It’s got a RCA 1802 processor, that was also used in space ships and satellites like the Voyager, Viking and Gallileo spaceships.
I built this from a kit around a RCA 1802 processor. It had one full quarter Kilobyte of memory, a two digit hex output, a seventeen key keyboard and one LED we could have blink and some digital inputs and outputs. One had to program it in machinecode starting from address zero, one hexadecimal byte followed by an enter at a time. On this board, I learned to program machine-code and assembler.
Later on I added the vertical “Giant-Board” and with that we were able to save programs on cassette tapes and to edit memory directly per address!
Still I was able to program my little model railroad with it.