5 ms·
These are iconic in the sense of "historical and influential". But I think only the Z80 and 6502 still have a big community still excited about them as 8-bit p
by SeanLuke 3y ago
These are iconic in the sense of "historical and influential". But I think only the Z80 and 6502 still have a big community still excited about them as 8-bit processors specifically, which I thought was the basis of the piece.
I wonder if to this we should add the Atmel Atmega328P, which is omnipresent in microcontrollers, not the least of which is the Arduino. It's always described as "8-bit" though it has wider addressing than that and is capable of doing 16-bit and 32-bit math. It's a Harvard architecture.
- brotchie 3y agoZ80 + some mods = Sharp LR35902 used in original Gameboy 6502 + some mods = 6502 used in original NES
- krallja 3y agoThe Gameboy is not a Z80, it's a separate 8080-descendant sibling. The NES had zero modification to the 6502 core, except that the binary-coded decimal flag was hardcoded to always be off (to avoid infringing on the one patent that MOS filed; chip design was not copyrightable at the time).
- PaulHoule 3y agoI like the AVR-8 which is a nice bookend to the 8-bit era in a lot of ways. It has more registers than the IBM 360 and also gets great performance with that Harvard architecture avoiding the very complex system of caching and pipelining you see in modern computers to fight latency. Unlike many of those 8-bit computers the AVR-8 doesn’t have any 16-bit arithmetic other than increment/decrement address modes that use the X, Y and Z register pairs unless you count the 8x8 MUL instruction that returns a 16-bit result or the MOVW instruction which copies a register pair and not just 1 register.
- JKCalhoun 3y agoMotorola's 68HC11 then. But these are microcontrollers, not microprocessors (although the distinction seems a little nitpicky).
- AnimalMuppet 3y agoI think the distinction then was more like non-existent. Most chips then didn't have on-board peripherals (for some value of "then"), so a CPU-intended-to-be-a-microcontroller and a CPU-intended-to-be-a-microprocessor looked very similar. Now we've added things to microcontrollers (serial ports, GPIO pins, timers, etc.) and other things to microprocessors (FPUs and memory managers). But back in the day, was a Z80 a microcontroller or a microprocessor? Yes.
- JKCalhoun 3y agoI have always assumed the distinction was whether it had its own on-board memory or talked over the bus to external memory. That's a kind of who-cares thing in my mind.
- AnimalMuppet 3y agoOh. Hmm. Yes, I could see that. [Edit: "Memory" including both RAM and ROM. Microprocessors usually didn't have code - even boot code - in internal ROM.]
- kps 3y agoToday I would make the distinction between those that are readily end-user programmable (microprocessors) and those that aren't (microcontrollers). Certainly many in this article were originally designed for what now would be microcontroller applications, but the fact that they couldn't then do on-chip ROM let hobbyists repurpose them into general-purpose microcomputers.