A Z80 on RESET, starts executing from 0x0000. This is why the ZX machines and so many others have ROM at the bottom of the address space. Presumably an 8080 is the same. But as I recall, a CP/M binary is loaded into memory from address 0x0100 and run from there. Why should these be so close together?
It means that someone who is just designing a new CP/M computer is forced to put some kind of bankswitching in place, just to be able to boot the thing. If I wanted to design an operating system, I wouldn't put the application's entry point in read-only address space.
Have I got this wrong? What is the rationale behind this decision?
