[hatari-devel] Twelve demo bombs with fast-forward and freezes on Falcon?

[Eero Tamminen]

Hi,

I just tried Twelve demo:
	http://pouet.net/prod.php?which=56966

ST version sounds fine, but I think with STE emulation the sound
isn't right (or at least it doesn't sound the same as with ST emu).


Additionally, if I use "--fastforward yes", it crashes at startup to:
Bus error bget at 00400000

I remember there were problems also with other demos when using
fast-forward with DMA sound.   Any idea yet why?


With Falcon (old UAE CPU) emulation, Twelve gets stuck in the beginning
(with or without fast-forward).  "profile" command tells that it's looping
here:
-----
> profile counts
addr:           count:
0x0233ca        60.00%  25110785
0x0233c8        40.00%  16740873
0x01f450        0.00%   1504
-----
> disasm 0x01f450
$01f450 : 4e73                                 rte
----
> disasm 0x0233c8
$0233c8 : b051                                 cmp.w     (a1),d0
$0233ca : 66fc                                 bne.s     $233c8
$0233cc : 4e75                                 rts
----
> r
D0: 480007ff D1: 48000057 D2: 00000001 D3: 0000ffff 
D4: 04440500 D5: 00500550 D6: 00050505 D7: 00000001 
A0: ffff8922 A1: ffff8924 A2: 0001f54a A3: 00020638 
A4: 0001e284 A5: 0001e284 A6: 003fbfc6 A7: 0001f26c
...
----
I.e. the code loops on testing Microwire data register for a value it
doesn't get.  Is the demo supposed to work on Falcon?


Btw. I was thinking of adding a "history" command to Hatari debugger, with
which you can set how many instructions back the debugger will remember
execution and be able to show previous values.

For first I was thinking of storing just the PC to backtrack branches that
have happened e.g. before a breakpoint (without flooding the console like
disasm trace does), but it could later store also all CPU registers and
anything else you might be interested about...


	- Eero