PLASMA VS 6502

Yeah, it’s better to use a “high-level” language designed for the architecture, such as this: https://github.com/dschmenk/PLASMA

The developer would abandon this due to the inadequacies of the 6502 to handle a language like Java. He didn't give up though!

> PLASMA is a combination of operating environment, virtual machine, and assembler/compiler matched closely to the 6502 architecture. It is an attempt to satisfy a few challenges surrounding code size, efficient execution, small runtime and flexible code location. By architecting a unique bytecode that maps nearly one-to-one to the higher-level representation, the compiler can be very simple and execute quickly on the Apple II for a self-hosted environment. A modular approach provides for incremental development and code reuse. The syntax of the language is heavily influenced by assembly, Pascal, and C.

https://github.com/dschmenk/PLASMA

For a younger, student electrical engineer, they could easily gain the appreciation for the engineering that went into these things. Especially as a someone who wrote a lot software prior to completing my EE training, I wanted to learn on something that was fairly “pure” to learn major concept and patters on: a large MCU that only breaks out into a bunch of connectors is not it.

I would love to be able to teach (or have had the opportunity to learn) system architecture from analysis of arcade cabinets, starting with a CPU, adding ram, rom, peripherals, etc. Ben Eater’s 6502 computer kit[0] comes very close and is closer to the ballpark of what I would want out of a learning experience.

[0]: https://eater.net/6502

The biggest hurdle to build an Apple 1 replica is getting the parts for which no modern replacement exist, like the funky 1024 X 1 shift registers in the video display terminal circuit. These represent the bulk of the costs. As an alternative, you can get real close to the Apple 1 with Ben Eater's 6502 breadboard computer project. One of the most recent videos actually shows how WozMon (the original Apple 1 "operating system") runs on it.

Thanks for the reply. As far as 6502s go, this link will tell you everything you need to know to get up and running...https://eater.net/6502

I know you asked about a soldering kit, but there is this breadboard 6402 kit that comes with all the chips. https://eater.net/6502 I highly recommend getting ther serial kit as well.

Very nice! Can you add the updated schematic also on https://eater.net/6502?

I think the 6502 and Z80 processors would be good options. It seems like both have good supporting communities, and you can source the parts easily (and they're not crazy expensive). If you end up going with the 6502, Ben Eater's video series is helpful. I would expect there are similar video series out there for Z80.

Modern systems are complicated, you often can't communicate directly with the CPU, you need to deal with the underlying operating system, interacting with the kernel and making system calls. So if you plan to write a whole program, it's easier to do some embedded programming with an Arduino or a 6502 or something. I'd recommend watching Ben Eater's series of videos on this subject.

Have you been following Ben Eater's long-running build a 6502 computer series? It's pretty great!

Did you have the LCD working previously in 8-bit mode? Do you have the rest of the VIA (U5) wired up as shown in Ben's schematic at https://eater.net/6502?