[B2-devel] Hello, and a few questions

[<ni...@in...>]

	Hi. I am working on porting B2 to MacOS X (Unix + new GUI).
Christian suggested I join this list, so here I am.


	Firstly, the question you must be asking yourself ...
Why would I want to emulate a Mac on a Mac? (apart from insanity)

1) Mainly because OS X only supports the emulation of programs
   that run under OS 9. I have some programs that only work under
   OS 8.5, some that require a 68020, and some that only work on
   a monochrome Mac

2) I don't have a copy of OS 9, and I am not planning on buying
   a copy just yet (hoping that Apple will bundle it at a discount)



	Here is what I have been doing:

* Installed a compiler (OS X PB doesn't come with one by default),
  and tried to compile Unix source for B2. Config failed,
  because OS X PB doesn't come with an X windows server by default

* I installed a demo X windows server, Xtools. After some fiddling
  around with the config files (OS X libraries are a bit different)
  and some header files (missing pthread & nanosleep prototypes),
  I got a version that mostly worked
  (some screen bit depths failed, but that may be the X server)

* I decided that a port to the "native" windowing system would be
  of more use to most people (I may also port to one of the free
  X servers later), so I have been learning about the foundation
  class libraries (Cocoa) and the developer kit (ProjectBuilder.
  Nice integrated application for building C, C++, Java and
  Objective-C, which invokes gcc and gdb to do all the hard work)

* At the moment, I have a B2 that outputs into a window at 24bit
  depth, but that doesn't yet accept input (will do soon), and is
  really slow (there is a task that draws the frame base into the
  window a few times a second).

  If anyone wants to see what it looks like, I will mail the list
  a screen dump.

* The native GUI classes are only in Objective-C and Java. To make
  my life easier, I decided to go the Obj-C route, but this means
  that I have a lot of "wrapper" functions defined in C++ land,
  so that C can call the standard B2 C++ routines.



	Now, some items for discussion:

* The "flavour" of Unix that OS X uses is called Darwin.
  Any objections to there being a 'Unix/Darwin' directory
  for the low-level Unix stuff ? (audio, ether et c.)

* Since this isn't an X windows port, I really cannot use
  the Unix directory for video and main. So, is a directory
  'MacOSX' at the same level as Amiga, BeOS and Unix OK?

* I would like to have the ability to "Interrupt" and "Restart"
  a hung B2 emulation (most real Macs have two buttons for this).
  The sensible way to do this would seem to be to define two new
  interrupt flags in main.h, e.g.:
	INTFLAG_NMI = 32	// Non maskable interrupt
	INTFLAG_RESET = 64	// Hard reset
  and handle those in the emulator.

  Now, I can see that TriggerInterrupt() sets a bit to tell
  something else to handle an interrupt, but I cannot see what
  actually processes the InterruptFlags variable.



	I also have heaps of questions about the source code

(e.g. why does Unix need an XPRAM watchdog?
      why does Unix use this:
#ifdef NANOSLEEP
		struct timespec req = {1, 0};
		nanosleep(&req, NULL);
#else
		usleep(1000000);
#endif
      to sleep for a minute when sleep(60); would suffice?)

but they can certainly wait until I have got a bit more code working,
and then built against the latest versions (I am using 0.8.1?)

-- 
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