Two Stop Bitsnew | comments | tags | ask | submitlogin
  • Rochus 17 days ago | parent | on: Apple Lisa Pascal Compiler sources
    > seems to be an empty ZIP file

    Same here. But the converted files are ok.

    > some stuff seems to be unimplemented

    As far as I understand, the provided files don't represent the latest compiler version. So maybe a later version had a better optimizer. But it's good to have the sources anyway, so I can use it to clarify language issues for my forthcoming Lisa Pascal compiler/transpiler.

    reply
    • me 17 days ago
      There's also some early Mac support in the compiler (there's a "MacFlag" that modifies details of the code generation). It's definitely good to have the sources and also a nice example of a compiler for my students.
      reply
  • Rochus 31 days ago | parent | on: The UCSD p-System, Apple Pascal, and a dream of cr...
    Cool project. Is the discussed p-system still 16 bit, or does it support a larger address space?
    reply
    • mbessey 30 days ago
      You're limited to 64k on the AppleII, but one of the extensions to standard Pascal that Apple Pascal supports is "segments", where you can break a larger program into multiple code segments, which can replace each other in memory.
      reply
      • bmonkey325 29 days ago
        Turbo Pascal had a similar method where code segments could be swapped in and out via .OVL files that were created at compile/link time.

        https://secondboyet.com/articles/publishedarticles/theslithy...

        reply
    • KODust 31 days ago
      Apple Pascal supported > 64k of RAM on suitable machines, so it probably already did?
      reply
      • Rochus 31 days ago
        Apple Pascal on the Apple II was restricted to 64 K memory; this limitation was due to the 6502's 16-bit address bus. The Apple III with it's 6502A could address 256 K, but only by bank switching; pointers remained 16-bit. The later Pascal versions (after Apple III) did no longer use P-code, but compiled to native code.
        reply
        • KODust 30 days ago
          There was a 128k version of Apple Pascal available on the Apple II. My question, applicable to both this and the Apple III version, is: Was the bank switching managed by the developer or by the Pascal runtime? If it's managed by the runtime, the addresses must have been encodable with >16 bits.
          reply
          • thought_alarm 30 days ago
            All versions of Apple Pascal use 16-bit pointers, so data was always limited to a 64 KB address space. On the 128K Apple II, p-code was located in aux memory, and data was located in main memory.

            Apple III Pascal had similar limitations, with separate 64K address spaces for p-code and data. On machines with more than 128 KB of RAM, there were assembly routines available for allocating additional memory and swapping data memory.

            reply
  • Rochus 38 days ago | parent | on: Atari ST turns 40 today
    The beginning of MIDI workstations; remembering Lengeling's and Steinberg's first programs; these were great times for musicians.
    reply
  • Rochus 82 days ago | parent | on: Celebrating the 30th Anniversary of Delphi version...
    Delphi was a significant achievement, and it's still relevant.
  • Rochus 105 days ago | parent | on: Bill Atkinson interview on Apple Lisa Source Code ...
    It's an interesting interview, actually recorded on 2022, even before CHM published the source code, and it's only about 30 minutes long.
  • Rochus 445 days ago | parent | on: Apple Lisa Operating System Reference Manual (PDF,...
    And here is a tool to browse and navigate it: https://github.com/rochus-keller/LisaPascal
  • Rochus 469 days ago | parent | on: Introducing Darkstar: A Xerox Star Emulator
    Amazing, also that it's implemented in C#.

    Star was apparently implemented in Mesa. Does anyone know whether the source code of Star was published?

  • Rochus 484 days ago | parent | on: Document-Centered UIs and OOP – How Will They Affe...
    It's rather about OpenDoc and OLE/COM. But there was indeed a user interface framework using CORBA, called Fresco, which was a successor of the InterViews user interface framework, and pretty complex and slow. CORBA and DCOM silently vanished when EJBs and .NET became popular.
  • Rochus 496 days ago | parent | on: History of The Graphical User Interface (GUI): A W...
    That's a nice documentary, thanks for sharing. It's also recommended for all people who still think that graphical user interfaces were invented at Xerox Parc (which is not true of course).
  • Rochus 498 days ago | parent | on: Late 70s and 80s: forget BASIC, we had Pascal and ...
    It all started with Object Pascal and MacApp.
  • More
lists | rss | source
Search:
Two Stop Bits is a discussion web site about retro computing and gaming.