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#120646 03/25/22 10:10 PM
Joined: Mar 2004
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bobz Offline OP
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Hello,

I am trying to play with Super NES Super Scope but I didn't manage to make it work. I have seen no "not working" warning screen so maybe I misconfigured something.

I have managed to install sscope device on port 2, but after this I see mainly two behaviors depending the game I am trying to play:
- either the trigger does not work (or works one or two times during start menu, then stops working)
- or where ever the cursor is, shoot is always done at the same place (at the center of the screen)

Does anyone reproducing this ?

bobz #120647 03/25/22 10:25 PM
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kmg Offline
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bobz, I see the same, though I've never tried this device before. The source file says: "TODO: x,y positions are not correctly latched", but I don't know if that means they are supposed to be slightly off or if this indicates it's never been working. It should obviously be flagged if the latter.

bobz #120648 03/25/22 11:21 PM
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It looks to me like snes_console_state::gun_latch_cb is the issue:

Code
//  m_ppu->set_latch_hv(x, y);  // it would be more accurate to write twice to WRIO register, first with bit7 = 0 and then with bit7 = 1
	m_ppu->set_latch_hv(m_ppu->current_x(), m_ppu->current_y());

The intent is to latch the current H/V position of the beam, which is what happens with the real hardware, since the latching occurs when the Super Scope detects the beam and pulls an I/O pin low on the controller port.

However, in MAME's case, this callback seems to be called whenever the game polls the joypad button states, which can happen at any time (including automatically during vblank). The result is that the actual cursor position gets ignored in favor of whatever the beam position happened to be when the button polling occurred.

bobz #120650 03/26/22 04:20 AM
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bobz #120665 03/29/22 01:50 PM
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bobz Offline OP
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Yes that's it. Thanks


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