That has nothing to do with their actual point; Turbo C could perfectly well support: void init() { asm("ax"(0x13)) { int 0x10 } } and as TFA sugges

That has nothing to do with their actual point; Turbo C could perfectly well support: void init() { asm("ax"(0x13)) { int 0x10 } } and as TFA suggests, plenty of implementations use the string-syntax without any register/clobber extensions.