I have a feeling Markus is referring to typing in machine code (in a totally opaque way) using DATA statements combined with a small loader written in Basic.[1] Here's an article discussing this approach.[2] This was very common in the computer magazines during the 80s. You learn a lot about patience and attention to detail, if nothing else. There were attempts to mitigate this..[3]
But there were plenty of magazine and book listings that had very little in the way of machine code and that were mostly regular program code.
Don't forget that DATA statements just contain comma separated constants, and they were useful for a lot of stuff, not just POKEing a byte into memory. Manipulating these constants gave some people their first taste of 'reverse-engineering' level data. :-)
And the fact that people were typing in machine code, to directly manipulate the hardware, is pretty impressive. It's even more impressive if they went on to learn more about assembler in order to modify the code somehow. Instruction manuals for the machines included information about machine language programming.
Don't forget that DATA statements just contain comma separated constants, and they were useful for a lot of stuff, not just POKEing a byte into memory. Manipulating these constants gave some people their first taste of 'reverse-engineering' level data. :-)
And the fact that people were typing in machine code, to directly manipulate the hardware, is pretty impressive. It's even more impressive if they went on to learn more about assembler in order to modify the code somehow. Instruction manuals for the machines included information about machine language programming.