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Comment by MalphasWats | Hacker News Reader

It's incredible how influential Ben Eater's breadboard computer series has been in hobby electronics. I've been similarly inspired to try to design my own "retro" CPU.

I desperately want something as easy to plug into things as the 6502, but with jussst a little more capability - few more registers, hardware division, that sort of thing. It's a really daunting task.

I always end up coming back to just use an MCU and be done with it, and then I hit the How To Generate Graphics problem.

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Funny enough, that's exactly where this project started. After I built his 8 bit breadboard computer, I started looking into what might be involved in making something a bit more interesting. Can't do a whole lot of high-speed anything with discrete logic gates, so I figured learning what I could do with an FPGA would be far more interesting.

Registers can be worked around by using the stack and/or memory. Division could always be implemented as a simple function. It's part of the fun of working at that level.

Regarding graphics, initially output serial. Abstract the problem away until you are ready to deal with it. If you sneak up on an Arduino and make it scream, you can make it into a very basic VGA graphics card [1]. Even easier is ESP32 to VGA (also gives keyboard and mouse) [2].

[1] https://www.instructables.com/Arduino-Basic-PC-With-VGA-Outp...

[2] https://www.aliexpress.us/item/1005006222846299.html

I was about to recommend the Parallax Propeller (the first one that's available in DIP format), but arguably, that one is way more complex to program for (and also significantly more powerful, and at that point you might as well look into an ESP32 and that is "just use an MCU" :))

And yeah, video output is a significant issue because of the required bandwidth for digital outputs (unless you're okay with composite or VGA outputs, I guess they can still be done with readily available chips?). The recent Commander X16 settled for an FPGA for this.

I feel like the CX16 lost its way about a week after the project started and it suddenly became an expensive FPGA-based blob. But at the same time, I'm not sure what other option there is for a project like that.

I always got the impression that David sort of got railroaded by the other members of the team that wanted to keep adding features and MOAR POWAH, and didn't have a huge amount of choice because those features quickly scoped out of his own areas of knowledge.

I think so too - it must have been a great learning experience for him though, but for me, the idea of "The best C64-like computer that ever existed" died pretty quickly.

He also did run into a similar problem that I ran into when I tried something like that as well: Sound Chips. Building a system around a Yamaha FM Synthesizer is perfect, but I found as well that most of the chips out there are broken, fake, or both and that no one else makes them anymore. Which makes sense because if you want a sound chip in this day, you use an AC97 or HD Audio codec and call it a day, but that goes against that spirit.

I think that the spirit on hobby electronics is really found in FPGAs these days instead of rarer and rarer DIP parts. Which is a bit sad, but I guess that's just the passage of time. I wonder if that's how some people felt in the 70s when CPUs replaced many distinct layouts, or if they rejoiced and embraced it instead.

I've given up trying to build a system on a breadboard and think that MiSTer is the modern equivalent of that.

> I think that the spirit on hobby electronics is really found in FPGAs these days instead of rarer and rarer DIP parts. Which is a bit sad, but I guess that's just the passage of time. I wonder if that's how some people felt in the 70s when CPUs replaced many distinct layouts, or if they rejoiced and embraced it instead.

Microcontrollers have taken over. When 8kB SRAM and 20MHz microcontrollers exist below 50-cents and at miniscule 25mm^2 chip sizes drawing only 500uA of current... there's very little reason to use a collection of 30 chips to do equivalent functionality.

Except performance. If you need performance then bam, FPGA land comes in and Zynq just has too much performance at too low a cost (though not quite as low as the microcontroller gang).

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Hobby Electronics is great now. You have so many usable parts at very low costs. A lot of problems are "solved" yes, but that's a good thing. That means you can focus on solving your hobby problem rather than trying to invent a new display driver or something.

Another advantage of hobby anything is that you can just do, and reinvent whatever you want. Sure, fast CPUs/MCUs exist now and can do whatever you want. But if you feel like reinventing the wheel just for the sake of it, no one will stop you![1]

I do think some people that remember fondly the user experience of those old machines might be better served by using modern machines (like a raspberry pi or even a standard pc) in a different way instead of trying to use old hardware. That's from the good old Turing machine universality (you can simulate practically any machine you like using newer hardware, if what you're interested in is software). You can even add artificial limitations like PICO-8 or TIC-80 does.