In the early days of 'Home Computing', many of us couldn't afford (or sometimes didn't even have the amount of RAM necessary) to run an assembler. So we used pe

In the early days of 'Home Computing', many of us couldn't afford (or sometimes didn't even have the amount of RAM necessary) to run an assembler. So we used pencil and paper along with a Z80 or 6502 instruction code chart to produce our machine code by hand. It paid to have a good skill with hexagesimal mental arithmetic to work out the JUMPS and CALLs. The surprising thing was that most of the time our code actually worked.