Overlanders european demo - Hidden screen?

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caffeinedemon
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Overlanders european demo - Hidden screen?

Post by caffeinedemon »

Hi,

In the top left corner of the main menu for the european demos, there's this door, which appears to be inaccessible..

Image

Is this a hidden screen? (and if so how do you access it?) - or is it just decoration?
mlynn1974
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Re: Overlanders european demo - Hidden screen?

Post by mlynn1974 »

Hi,
As far as I can see it is only decoration. In the attached screenshot pressing space doesn't load another screen. The sprite can move right but not left.

start:
0x77ea bra.s $7800

Estimated sprite position:
0x15332 00 35 00 20
0x15332 00 3c 00 90

I couldn't debug it with STeem Debug 3.2 because this demo will not run on that version. It also doesn't run if Ultimate Ripper is installed. Instead I used SainT 2.4 but when I tried to edit memory it would crash. Instead I used the debugger to scroll back in memory and stepped through a few functions to find the sprite positions.

I had to use my hexsearch utility to find the address offset within a snapshot:
hexsearch 3b002000 SainTMemoryShot_1.SainT

I dumped memory to a slot (attached) and adjusted the x value to 0x26 using Microsoft Visual Studio's binary editor.
You do not have the required permissions to view the files attached to this post.
Still got, still working: Atari 4Mb STe, 520STFM (x2), 2.5Mb STF, Atari 2600JR, Flashback 8 Gold.
Hardware: Cumana CSA 354, Ultimate Ripper, Blitz Turbo, Synchro Express II (US and UK Versions).
terence
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Re: Overlanders european demo - Hidden screen?

Post by terence »

hello

it would be easier to go a level above, in the loader code. most of the times, the main menu sends a demo number to the loader, that is all the time in the memory, at very low level of memory, like $140 ( as done by mcoder for the transbeauce 2 demo for example )

i was close to ovr at this time, and i was at STNICC when this demo was released, and i don't have memory of an hidden screen.
mlynn1974
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Re: Overlanders european demo - Hidden screen?

Post by mlynn1974 »

terence wrote: Tue May 18, 2021 7:44 am it would be easier to go a level above, in the loader code.
That would be a good idea, but we don't know the range of numbers or disk number selector values because The European Demos is a 2 disk demo.
Changing the sprite position to behind that block also shows a glitch in the hardware scroll routine. The sprite isn't supposed to be there.

The only hidden screen I know if in The European Demos is if you boot in High Res you get a High Res demo!
Still got, still working: Atari 4Mb STe, 520STFM (x2), 2.5Mb STF, Atari 2600JR, Flashback 8 Gold.
Hardware: Cumana CSA 354, Ultimate Ripper, Blitz Turbo, Synchro Express II (US and UK Versions).
terence
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Re: Overlanders european demo - Hidden screen?

Post by terence »

ok so i digged in the demo
using steem SSE version, run the demo until main menu.
stop it
put a breakpoint at $19F6, run it, choose a door
put the number of the demo in register D0:

01 = reset
02 = presentation Mr Bee
03 = presentation 2
04 = ?
05 = ?
06 = main menu
07 = ?
08 = xbios men

...
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