Posted By
Csabo
on 2010-05-31
11:26:27
|  Need some help testing
Guys,
Gaia and I are trying to look into an issue. It's with T A O R. We're trying to determine if the odd behavior (blank screen) is a bug in emuation or a software bug. The problem is we're getting inconsistent results. If you have the time and opportunity, could you please try to run this program in YAPE and Plus4Emu, and more importantly on the real iron, and let us know if it works or not?
|
|
Posted By
AaronGale
on 2010-05-31
12:14:24
| Re: Need some help testing
Just tried to run the version off Plus4World in Yape and I see the initial unpacker run and then black screen and rumbling white noise.
Tried to reload and do: "If you get a blank screen, enter >FF07 8 in the emulator monitor"
Same result.
|
|
Posted By
Csabo
on 2010-05-31
13:11:03
| Re: Need some help testing
Ok, how about in Plus4Emu? (If you do run it, please let us know which version and if you've changed any settings  )
|
|
Posted By
siz
on 2010-05-31
14:25:09
| Re: Need some help testing
Initially a black screen but after changing $ff07 to 8 the screen appears. Both in YaPE and plus4emu.
Update: checked in ViCE: it works flawlessly. After decreasing(!) the compatibility in YaPE it works there too. :D
|
|
Posted By
Chicken
on 2010-05-31
14:49:04
 | Re: Need some help testing
I think, it's a bug in the code.
At first, I had the suspicion it was something similar to the "saved endadress -1 byte" issue there was with another program (which sometimes would depack correctly when the "last byte" was correct by coincidence.
It'll start correctly if the cursor is in the bottom line (25th) when you type RUN. (Still having the broken scroll but that's a different topic).
I was able to reproduce this 10 times in a row, though, just after a new start with the "Commodore..." stuff on screen, pressing RETURN a couple of times to reach the bottom line. It has something to do with the stuff in video ram when the program starts. I should check the code ;)
|
|
Posted By
Csabo
on 2010-05-31
15:01:22
| Re: Need some help testing
Gaia also found that decreasing the compatibility in YAPE fixes the issue. If think both YAPE and Plus4Emu emulate a TED feature which causes the blank screen, but VICE doesn't.
The weird thing was for him it did not in Plus4Emu, but for me it did. Chicken's comment just made me realize what the difference was: I used the autostart feature in Plus4Emu! (I right-click the program file and click "Run with Plus4Emu".) However, If I load the program after the emulator has started, they it's the same blank screen for me as well. I can also confirm that running the program with the cursor being in the last line fixes it.
Conclusion: this is bug in the demo. Using the default settings, YAPE and Plus4Emu both correctly emulate the blank screen. In good/low compatibility, the demo runs in YAPE (just like in VICE), though it shouldn't. Also, as Chicken discovered, running the demo while the cursor is in the last line prevents the demo's bug from happening.
Good work guys, thanks for the help! I'm always so glad when I know there's a few of us around hacking this kind of stuff.
|
|
Posted By
Gaia
on 2010-05-31
15:20:47
| Re: Need some help testing
Wow, this was 1st class crime scene investigation, thanks guys (still worth to check the real iron though)
For the record, VICE as well as YAPE's intermediate compatibility mode does not care about the TED off bit. And it's exactly the one that is causing the trouble since the demo accidentally turns off the TED by writing $FE into $FF07.
|
|
Posted By
Chicken
on 2010-05-31
16:16:33
| Re: Need some help testing
Edited because it kept crashing every now and then.
Edited again...
LOAD and enter in TEDMON
>1198 78 EA
>11DA 58 EA
Not 100% sure if this works all the time, yet. But I think it fixes the TED issue.
Edited again...
Since that's just taking care of the TED crash and the scroll text was still missing I made an "all in one" patch (Thanks Csabo ;) ). I tried to change as few bytes as possible so it's a dirty hack but does the job.
>1149 A9 12 85 D9 78
>1198 85 D8
>11DA 58 EA
The fixed version can be saved ($1001 - $2260) and should RUN.
|
|
