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Comment by phendrenad2 | Hacker News Reader

There's something magical about writing code in C for these old 8-bit and 16-bit CPUs. You really feel like you're in control. You can inspect the assembly output and actually understand it. You can do inline assembler to optimize critical sections. 32-bit CPUs lose some of that magic, because the instructions sets are usually much more complex. However, RISC ISAs like RISC-V are still plenty of fun...

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> There's something magical about writing code in C for these old 8-bit and 16-bit CPUs.

Eh, I'm not sure I would agree, about the 6502 specifically. It's a pretty bad match to C since e.g. it doesn't have a relocatable stack and common pointer-based operations are quite clunky despite the provision for several address modes. FORTRAN-like languages really do match quite a bit better. In a different way, so does FORTH.

Also, plenty of people did have fun writing assembly code for the MC68k, which is a 32-bit CISC architecture. It's really only x86 (and maybe VAX) that tends to be a bit clunkier.

Having written 6502 assembly but not targeted 6502 with C, I tentatively agree, but if you can fit your program in a 256 byte stack, things should be... mostly fine? Except for the fact that you want to do pointer indirections through the zero page. Clunky!

Personally if I'm going to have fun writing assembly for a project like this, I'm not too picky about the particular architecture.

It is clunky, but the instructions are fast. Always thought that was an interesting trade off.

They’re fast, but you’re not using them well if you’re writing C, because the compiler is not good at putting things like local variables, function arguments, or globals in the zero page. It’s only 256 bytes and you can’t easily share.

So for 6502 I would rather not be writing C.

Nor would I.

Check out PLASMA. That is being used to develop the game lawless legends. It's pretty damn impressive.

The dominant C compiler (CC65) has a separate stack for parameters and local variables, and keeps SP as a pointer in zero-page. This is a nice general approach that allows for deep stacks, recursion, and lots of locals, but isn't very efficient.

Newer experimental 6502 languages either forbid recursion (cowgol) or limit parameters passed to functions (C02), but I can see a language using a hybrid of stack and zero page to keep locals and parameters.

The drawback of high-level programming on the 6502 is you are always looking for ways to make it better... :)

As someone that started coding back when those systems were modern, if you want to be in control learn Assembly.

Kids these days. If you want real control, learn to move the patch cords. Otherwise, you're stuck with only one set of opcodes.

;-)

(No, I never worked on such a system... but my mother did.)

IIR, C wasn't even available for most of these systems as they probably didn't have the local resources to compile their own code.

On what concerns the Spectrum range, there were some pseudo C compilers that you could type in, but there were basically toys given the 48KB space.

With the 128KB +3A model you could use CP/M, which had a better compiler available, still a pseudo C toy compiler versus the real thing on UNIX.

We only used such compilers for homework assignments.

The MSP430 is a fun way to get back to that sort of simplicity with a fairly modern chip; it's a 16-bit processor with a focus on power efficiency. They've got a GCC toolchain and a port of the Processing IDE ('Arduino') called Energia:

https://energia.nu/

Also, some of the newer ones have small amounts of nonvolatile FRAM instead of separate SRAM and Flash banks.

... and it is a lot more fun when the toolchain runs on the target itself. With microcontrollers it's hardly possible (but see RetroBSD), but not needing a workstation to service an otherwise self-contained little machine somehow feels special.

I found MIPS (R3000), SPARC, and MC68k about the right size for an ISA. Things like PIC (and similar microcontrollers) and older 8bit CPU like the 6502 and Z80 always felt a little limiting to me. I think those (MIPS etc.) were also a great point for higher-level (C, etc.) languages to be useful/interesting.

I guess each to their own though.

> You can inspect the assembly output and actually understand it. You can do inline assembler to optimize critical sections. ...

You can really do this on any modern platform as well. It just takes a bit of effort. Understanding performance characteristics can be an order of magnitude harder, though.

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