monocasa 16 days ago

I love that this site has an Easter egg if left idle long enough.

michalpleban 16 days ago

How much room is there for a custom PCB? I'm a 6502 guy so I would like to keep the case but put something there with my favorite CPU.

  • rollcat 16 days ago

    I've learned Z80 and 8051 a decade or two ago, and then forgot everything. Honestly both were easy to pick up, but I assume you're opinionated and/or an expert?

    Anything in particular that you like about the 6502?

    • PaulHoule 16 days ago

      I think people like the way the 6502 wires up to peripherals. Myself I think the Z80 is much better because it has enough registers and addressing modes that you can write compilers for it. I know they had C compilers for it in 1984 because I typed in a C program for CP/M from Byte magazine and got it to run on my 6809-based TRS-80 Color Computer. Programming languages for the 6502 were usually implemented with virtual machine techniques like

      https://en.wikipedia.org/wiki/SWEET16

      or the truly atrocious

      https://en.wikipedia.org/wiki/UCSD_Pascal

      which was one reason a generation of programmers hated PASCAL with a passion and declared you could pry BASIC from our cold dead hands.

      Myself I'd want to hollow it out and put something based on

      https://en.wikipedia.org/wiki/Zilog_eZ80

      because it is way faster, has a bigger address space, and has wider registers so you can do pointer math over that bigger address space unlike this turkey

      https://en.wikipedia.org/wiki/WDC_65C816

      A lot of people enjoyed writing assembly for the 6502 back in the day though.

      • pjmlp 15 days ago

        UCSD Pascal was marvelous over the plain ISO Pascal from early 1970's, and the inspiration for Clascal and Object Pascal at Apple, that eventually was embraced by Borland, and a few competitors like TMT that wanted a piece of the Pascal pie on PCs.

        And the Constellation OS from Corvus Systems.

        C compilers on Z80, at least on Spectrums were really lousy in terms of code generation, plus the whole dev experience unless on a +3 A with drive, those kind of machines were designed for a BASIC interpreter + Assembly.

      • rollcat 15 days ago

        eZ80 looks cool. Indeed looks like an interesting mcu to build a tiny general-purpose computer from scratch. (Somehow I always found bank-switching kinda ugly, address space is better when there's more of it.)

        I find it fascinating how these 70s/80s microprocessors still keep getting pushed with backward-compatible updates. (Most notably, x86-64.)

    • michalpleban 15 days ago

      I just have a few decades of experience with 6502 and none with Z80, so it would be much easier for me to program it.