Basilisk II

Hi,

> Because of the stagnant state of BeOS/ppc, the superiority of open sourced
> software, and the success of Basilisk II, Marc Hellwig and I (actually just
> me because Marc left the decision to me) have decided to make SheepShaver
> open source, too.

Great!

>  1. The most important issue to be resolved is of course: how should this
>     combined emulator be named? :-)

- PDM Emulator
Piltdown Man was the first PowerMac prototype which had a Centris case
<http://www.applefritter.com/>

Or "Portable and Definitive Macintosh Emulator" ;-)

>  2. SheepShaver only has native PowerPC support. There is no PowerPC emulation
>     for other systems yet (I've started with a simple interpreter but this
>     would need a lot more work to be usable, let alone efficient enough).

Talking about PPC Emulation, I realized when I finally set up a PPC
cross-compilation system that PSIM was only twice as slow as UAE on the
benchtest program that comes with PSIM. Taking into account the fact
that PSIM emulates a complete MMU, that's not so bad, imho.

There are other alternatives but I don't know their current status
- Lauri's interpreter (most recent ;-)
- Bill Huey's JIT Compiler
- Bill Meyer's interpretive core (defintively stalled)

> In any case, I would like to have at least one more stable release of
> Basilisk II (with JIT) before starting with this (probably not this year
> any more).

Bernie Meyer has just released a new version of his JIT Compiler. That's
really impressive but changes were so radical that this will take more
time than I expected, and I am running into three very busy weeks :-/

BTW Christian, a PPC Emulation is a great project and I am willing to
contribute. It happens that I am in final year (in computer science) now
and I have a 4-month training period (internship) to carry out in
February. Pure dream: what if a great company committed to Open Source
Software gives me a chance to participate to such a project and others ?
;-)

Bye,
Gwenole.

Gwenole asked:

> 1) BTW, do you have a solution for direct addressing ?

	REAL_ADDRESSING builds just seemed to crash for me :-)
When I started investigating, I got lost in the mmap() stuff
(manpages for some functions in OS X public beta are missing),
so I decided that I would get everything else working first.

> e.g. does MacOS X
> supports POSIX Extended Signal Handlers, the ones that can take a
> siginfo_t structure informing you about the address of an illegal
> instruction for example ?

	Doesn't look like it has them.


> 2) Is there and will it be possible to use Apple's DR Emulator located
> in ROM ?

* Only 30% of the machines that currently run MacOS X (i.e. >= G3)
  actually have the DR 68k Emulator in ROM. The others get it from
  the NewWorld ROM file on the System disk.

* I think we would need to be emulating a PowerMac before that code
  could be used. (I have seen the problems in calling Mac ROM code
  from Unix [MRG in NetBSD/Mac68k], and it isn't pretty)





Lauri commented:

> >2) Has a cyan cast.
...
> I think I had the same problem once:
> 
> http://www.kearney.net/~mhoffman/basiliskII/online.JPG

	Emulating a Mac in a PC emulator. How sick ;-)

> The color distortion looks quite similar.

	You at least had some red. I have none!

	The problem is caused by differing representations of 32bit
data in Basilisk & MacOS X's windowing (Quartz):

Basilisk _RGB	ARGB
Quartz   RGB_	RGBA
         ----	----
         0GB0	AGBA

	My current hack for this is to give Basilisk a bitmap pointer
that is offset by 1, so that it draws into the correct channels.
Incredibly, it works (I thought I would have word alignment problems).

	The correct fix for this would be to have another intermediate
memory buffer, and either rotate each 32bit word before copying, or
copy with my 1byte offset, but the emulator is slow enough already!


	Another problem is that the bitmap drawing classes do not
currently support 16bit bitmaps. They support 1, 2, 4 and 8 bits per
sample, but not 5 (for 555). The classes do adjust between source
and screen depth however, so for now I am just using 32bit, and
letting it be dithered or truncated.

-- 
| Nigel Pearson, nigel@... | "Reality is that which,   |
|   Telstra NW-D, Sydney, Australia.    |  when you stop believing  |
| Office: 9206 3468    Fax:  9212 6329  |  in it, doesn't go away." |
| Mobile: 0408 664435  Home: 9792 6998  | Philip K. Dick - 'Valis.' |

Hi,

I had updated JIT Basilisk a couple of weeks back and fixed the lazy
flusher. The compile_block() function now takes only 8% of the total
execution time compared to more than 50% in the past but without Lazy
Flushing!

That release is not in sync with Bernie's latest UAE-JIT IT Release but
it now enables JIT Compilation for FPU instructions. Unfortunately, that
is rather buggy and actually slower than JIT-FPU. bkoz: JIT-FPU
activated the old and buggy UAE FPU core.

That weekend, I started to reimplement the FPU core for supposedly
IEEE-754/854 behaved target FPU. That core also implements lazy
evaluation of FPU flags as Bernie did for his UAE-JIT IT Release. If
that FPE core works on our SPARC workstations then I will probably
commit it to the CVS as it makes scrollbars working too ;-)

BTW, any objection in moving all FPU related files to a fpu/
subdirectory of uae_cpu/ ?

Bye
-- 
Gwenolé Beauchesne - Web: <http://gwenole.beauchesne.online.fr/>
JIT Basilisk II, FAQ fr.comp.sys.mac.programmation

Christian answered a few of my questions:

> > [NMI/Reset]
...
> There's a TriggerNMI() in cpu_emulation.h which is
> currently unimplemented for the UAE CPU emulation

	I couldn't find this in 0.8.1, or the latest "snapshot".
Maybe it is in the latest version of the CVS file?


> (it works under AmigaOS, though). I think the BeOS port
> once had a "reset" capability, but it seems to have got lost somehow.
> Adding a Reset680x0() function might be in order.

	Calling newcpu.cpp's m68k_reset does all the resetting,
but because the emulator is an independant thread, most of the
time the emulator tells me "Your Mac program just did something
terribly stupid"


...
> > (e.g. why does Unix need an XPRAM watchdog?
> 
> The XPRAM contents are normally only saved when B2 quits. To avoid changes
> to the XPRAM from getting lost when the emulator crashes, a background
> thread looks for XPRAM changes every minute and saves the XPRAM if necessary.

	Fair enough. I see that the BeOS port has one too,
but that the Amiga port does not. Interesting.

-- 
| Nigel Pearson, nigel@... | "Reality is that which,   |
|   Telstra NW-D, Sydney, Australia.    |  when you stop believing  |
| Office: 9206 3468    Fax:  9212 6329  |  in it, doesn't go away." |
| Mobile: 0408 664435  Home: 9792 6998  | Philip K. Dick - 'Valis.' |

> On Tue, 28 Nov 2000 11:41:15 +1100 (EST), nigel@...
> wrote:
> 
> If anyone wants to see what it looks like, I will mail the list
> a screen dump.

Lauri answered:
> Welcome to the list. Yes please, I would love to see it. But could you
> please upload it somewhere and send the URL instead if it's
> a large image.

	OK. There is a version at:

http://www.zing.com/picture/pb170d94c2499614696882e49f59d1c52/ff20c279.jpg


Sorry that it:

1) Is scaled down in size.
   Looks like Zing does that on upload

2) Has a cyan cast.
   The Basilisk and MacOS X bitmap buffer layouts are in
   different formats, and I haven't worked out a fast way
   to copy the former to the latter with translation.

-- 
| Nigel Pearson, nigel@... | "Reality is that which,   |
|   Telstra NW-D, Sydney, Australia.    |  when you stop believing  |
| Office: 9206 3468    Fax:  9212 6329  |  in it, doesn't go away." |
| Mobile: 0408 664435  Home: 9792 6998  | Philip K. Dick - 'Valis.' |

[merging B2 & SS]
>  1. The most important issue to be resolved is of course: how should this
>     combined emulator be named? :-)

	Maybe "Basilisk III, the return of the SheepShaver" ?
Someone could probably produce a picture/icon that looked like
a cheesy movie poster.

	Or, you could always use something boring like MAE
(Macintosh Application Environment).

	I doubt that Apple will be using that name again :-)

-- 
| Nigel Pearson, nigel@... | "Reality is that which,   |
|   Telstra NW-D, Sydney, Australia.    |  when you stop believing  |
| Office: 9206 3468    Fax:  9212 6329  |  in it, doesn't go away." |
| Mobile: 0408 664435  Home: 9792 6998  | Philip K. Dick - 'Valis.' |