[HN Gopher] Tetris Max 2.9.1 and Macintosh System 6.0.8 Bugs
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       Tetris Max 2.9.1 and Macintosh System 6.0.8 Bugs
        
       Author : zdw
       Score  : 47 points
       Date   : 2023-07-29 03:19 UTC (1 days ago)
        
 (HTM) web link (www.bigmessowires.com)
 (TXT) w3m dump (www.bigmessowires.com)
        
       | altairprime wrote:
       | (2023)
        
         | mproud wrote:
         | Haha, I suppose a person might think this was an old bug report
         | drafted from 25 years ago!
        
       | dietrichepp wrote:
       | I've been doing some dives into Mac 68K programming recently, and
       | ran into the same question--what about color on System 6? Like
       | the author, I don't have a Mac which is both color and runs
       | System 6.
       | 
       | The old Inside Macintosh volumes are sometimes difficult to
       | follow. New features got added to newer system software versions,
       | and new features got added to newer ROM versions, and if you want
       | to support older Macs, then you sometimes have to search through
       | the volumes until you find when a particular feature was
       | introduced. (The original Inside Macintosh volumes are organized
       | in chronological order, corresponding to major ROM or system
       | software updates.) If you just look at the description of one of
       | the functions in the OS or toolbox, there's no mention of when it
       | was introduced.
       | 
       | I also discovered that despite my efforts to make a program
       | compatible with the Mac 128K and 512K, my programs won't run on
       | those systems. The 128K and 512K have the very first ROM version,
       | with the 64K ROMs, and I suspect that the application startup
       | code which ships with CodeWarrior checks for a 64K ROM and aborts
       | the program. So even if I'm careful to only use functions that
       | are available in the 64K ROM, my program won't run on a 64K ROM
       | unless I use a different toolchain or rewrite the startup code.
        
         | azalemeth wrote:
         | Naive question: what's wrong with quemu and this emulation
         | target?
        
           | duskwuff wrote:
           | qemu only supports one 68k Macintosh machine target (the
           | Quadra 800), which is too new to run System 6.
        
         | jamesfmilne wrote:
         | To target stuff that old I'd try MPW. I used to use Codewarrior
         | back in the day, but these days I prefer MPW, as its more like
         | developing on modern macOS/Linux.
        
           | dietrichepp wrote:
           | That's a good suggestion--I decided not to use MPW because
           | the CodeWarrior compilers are better, the CodeWarrior UX is
           | better, etc. For now, I'd rather drop 128K support and keep
           | using CodeWarrior. The binaries work just fine on Macs with
           | the 128K ROM (like the Mac Plus), and there are a number of
           | additional difficulties you face when developing for 64K
           | ROMs.
           | 
           | Some of the other difficulties--no MaxApplZone, the segment
           | manager behaves differently, and if you really want Mac 128K
           | support, you have to copy to an MFS formatted disk. Some
           | versions of the OS ship with broken MFS implementations,
           | presumably because nobody cared whether it worked. I suspect
           | that the segment manager behavior is a particularly thorny
           | issue because it affects the location of code segments in
           | memory, and you have to be careful when you only have 128K.
        
         | Someone wrote:
         | Check whether your code gets called by writing a _main_ that
         | doesn't use any traps but just loops clearing the screen, fills
         | it with black, clears it, etc.
         | 
         | If it doesn't get called, disassemble the startup code. It
         | can't be long.
         | 
         | I would use a version of ResEdit that has a built-in
         | disassembler (advantage: you won't have to run that on a 512k
         | Mac, but can use a beefier one or an emulator)
         | 
         | You also may want to use the earliest version of CodeWarrior
         | you can find, as support for System 6 may have stopped at some
         | time.
        
           | dietrichepp wrote:
           | CodeWarrior ships with the source code for the startup code,
           | but it is unfortunately somewhat long.
        
         | anthk wrote:
         | Check jcs's site. He writes unix/openbsd related code but it
         | has a section on System6 programming. https://jcs.org/system6c
         | Also, telnet to klud [DOT] ge to test his BBS hosted in a
         | System 6 machine.
        
       | yyyk wrote:
       | I wonder how well this would have run with Ardi. I used to run a
       | few older Mac games on it without serious issues some years ago.
        
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       (page generated 2023-07-30 23:01 UTC)