[FarmerPotato]

Code size would balloon if you try to format verbose error messages. I often look at the binaries of old EPROMs. I notice that 1) the amount of ASCII text is a big fraction of the binary 2) still just categories (“Illegal operation”). For the 1970s, we’re talking user programs that fit in 2K.

I write really verbose diagnostic messages in my modern code.

[kjellsbells]

There was also an implicit saving back then that an error message could be looked up in some other system (typically, a printed manual). You didn't need to write 200 chars to the screen if you could display something much shorter, like SYS-3175, and be confident that the user could look that up in the manual and understand what they're being told and what to do about it.

IBM were experts at this, right up to the OS/2 days. And as machines got more powerful, it was easy to put in code to display the extra text by a lookup in a separate file/resource. Plus it made internationalization very easy.