Yes, I programmed it purely with opcodes. The machine was just running a very basic "monitor" that let you write instructions and data into memory in hex and th

Yes, I programmed it purely with opcodes. The machine was just running a very basic "monitor" that let you write instructions and data into memory in hex and then let you run them. At first the machine did not even have a cassette interface, so there was no way to save programs and you had to type them in every time. The machine came with some examples, like Conway's "Life". Given that the machine really only had about 256 bytes of usable program storage (half the 1k was used for video) this wasn't quite as bad as it sounds but still pretty tedious. Actually when I first got a cassette interface I still had to type the cassette loader in by hand to boot :( Eventually I got the rom expansion that included the cassette loader and an assembler. Obviously writing a program directly into memory in opcodes does involve some upfront thinking, but you'd be surprised how "REPL-like" the coding experience could be :)