3 ms·

I still have my original copy of Zaks' book in my collection. I obtained it in 1981 from a friend. I did so much z80 assembly on the TRS-80 that I could "see"

by kator 12y ago

I still have my original copy of Zaks' book in my collection. I obtained it in 1981 from a friend. I did so much z80 assembly on the TRS-80 that I could "see" instructions in a hex dump before asking zbug to disassemble them. The z80 was quite the chip for its time and I enjoy reading these articles has they look back into the deeper inner workings of the chip. One could master the z80, I'm not sure many modern processors could be mastered at that level by a single programmer. They seem to have gotten so complicated that they're beyond comprehension in a single person's mind. I could be wrong but that's the general feeling I get. Sure you can be really good at them and maybe an expert in many applications of a modern complex processor but I doubt many people have a singular understanding of everything each chip has to offer. Or maybe I'm just getting old.. :-)

userbinator 12y ago
The 8086, which is based on the Z80, is not that much more complicated (even the opcode structure is similar, being an octal format), and same goes for the 80186. Things started becoming a bit more complex with the '286 and its protected mode, and then the '386+ with 32-bit and its various protected-mode enhancements really made it harder for a single person to master fully, but I think it was still mostly possible; the really hairy stuff started with 64-bit mode and all the extensions (e.g. virtualisation) that have been made to that since. On the non-x86 side, modern ARM SoCs like the ones used in smartphones are not all that much simpler despite a less complex CPU core - they're still thousands of pages of documentation in total.