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amilo3438 · 07 May 2021, 14:05

I have found something new about strange issue with " Tek/Rampage " circle scene on A1200 emulation.

Note: State file on the post $164 (page 9) is not good as it pass an very important part!
Also, the demo is AGA aware as on the loading screen gives info: AGA disabled!

I made an state file (for myself) just after the plane scene and did some testing:

1) In the loading scene of circle part and much before the music did "la la la" press F12 and change the CPU to 68000!
2) Return to emu and wait when the music end with "la la la" and again press F12 to change the CPU to 68020!
Note: The circle scene is not yet shown on the screen!

Now the circle scene will run with out problem with the CPU 68020.

According to this it seems the current 68020 emu mess something in the memory (in comparison to 68000 or JIT) just before the circle scene appears!
(So also that part of memory could be compared with 68000 to see what is different and why.)

PS.
This problem has nothing with CPU speed as I checked all possible combinations!
Also note there is no problem if you load state file, start it, press F12 and than change to JIT!
Also, the problem will still be there even with 68000 if you change from 68020 and after the music did "la la la" to the 68000!
I cant post any attachment as its all full! (hope Zarnal can make one state file that starts just after the plane scene is finish)

EDIT:
It will work with CPU 68020 only if both Cycle-exact Full and DMA Memory is off AND More Compatible in CPU options is off too!
But if the More Compatible is on it will still glitch! (seems like 680020 CPU prefetch mess something in the memory)

Note: The demo turns CPU cache off on start! (CACR=00000000)(so it is made to run w/o the cache)
If I force the cache to on with Shift+F12 "r cacr 1" when all Cycle-exact is off and More Compatible is on, I got squares instead of circles!
But if force the cache to on when all Cycle-exact is off and More Compatible is off, I got circles, so in this case the cache off/on does not change anything!

The 60020 JIT has also More Compatible option and testing the state file with JIT More Compatible on or off it still runs fine!
(so now it seems obvious that there is some strange problem in current 68020 More Compatible situation as JIT works fine with it)

07 May 2021, 14:05	#207
amilo3438 Amiga 500 User Join Date: Jun 2013 Location: EU Posts: 1,521	I have found something new about strange issue with " Tek/Rampage " circle scene on A1200 emulation. Note: State file on the post $164 (page 9) is not good as it pass an very important part! Also, the demo is AGA aware as on the loading screen gives info: AGA disabled! I made an state file (for myself) just after the plane scene and did some testing: 1) In the loading scene of circle part and much before the music did "la la la" press F12 and change the CPU to 68000! 2) Return to emu and wait when the music end with "la la la" and again press F12 to change the CPU to 68020! Note: The circle scene is not yet shown on the screen! Now the circle scene will run with out problem with the CPU 68020. According to this it seems the current 68020 emu mess something in the memory (in comparison to 68000 or JIT) just before the circle scene appears! (So also that part of memory could be compared with 68000 to see what is different and why.) PS. This problem has nothing with CPU speed as I checked all possible combinations! Also note there is no problem if you load state file, start it, press F12 and than change to JIT! Also, the problem will still be there even with 68000 if you change from 68020 and after the music did "la la la" to the 68000! I cant post any attachment as its all full! (hope Zarnal can make one state file that starts just after the plane scene is finish) EDIT: It will work with CPU 68020 only if both Cycle-exact Full and DMA Memory is off AND More Compatible in CPU options is off too! But if the More Compatible is on it will still glitch! (seems like 680020 CPU prefetch mess something in the memory) Note: The demo turns CPU cache off on start! (CACR=00000000)(so it is made to run w/o the cache) If I force the cache to on with Shift+F12 "r cacr 1" when all Cycle-exact is off and More Compatible is on, I got squares instead of circles! But if force the cache to on when all Cycle-exact is off and More Compatible is off, I got circles, so in this case the cache off/on does not change anything! The 60020 JIT has also More Compatible option and testing the state file with JIT More Compatible on or off it still runs fine! (so now it seems obvious that there is some strange problem in current 68020 More Compatible situation as JIT works fine with it) Last edited by amilo3438; 07 May 2021 at 17:34.