On Apr 29, 2016, at 7:16 AM, Fred Cisin <ci...@xenosoft.com> wrote: >>> And you do know what Apple MacOS was originally written in, don't you? >> On Thu, 28 Apr 2016, Chris Hanson wrote: >> >> The original Macintosh System Software was almost entirely M68000 assembly >> language. >> There were a couple parts of the original System Software that were written >> in Pascal, but by and large the space constraints of the 64KB ROMs and the >> 400KB floppy and the desire to eke every last cycle of performance out of >> the 8MHz CPU led to pervasive use of assembly. >> The APIs were defined in terms of both Pascal and assembly, which is what >> leads people to think that it was written in Pascal. > > How much was based on Lisa? What was THAT written in?
Not much. I think the Memory Manager was originally written in Pascal for Lisa but got rewritten in 68K assembly for the Mac. Lisa was designed to have 512KB to 1MB on a stock system, expandable to several MB, and also included an MMU & virtual memory. The original Lisa had two 860KB Twiggy drives and typically came with a ProFile, while the Lisa 2 included a 5MB or 10MB ProFile, so a Lisa system typically even had swap. Most of the lower-level portions of the OS were written in Pascal. The Lisa Office System applications and the Desktop were written in Clascal, a Smalltalk-style OO enhancement to Pascal that Apple hired Wirth to help design, which later turned into Object Pascal. All of the applications were based on the Application Toolkit, a Clascal framework implemented as a system shared library, whose design was a direct predecessor to MacApp. None of that would really fly on the Mac, with 64KB of ROM, 128KB of RAM, and a single Twiggy (later Sony 3.5in) floppy. -- Chris
