YLFAndy
commented
11 months ago More details from issue https://github.com/MiSTer-devel/Saturn_MiSTer/issues/42:
The code for the Salamander 2 loader in the Salamander Deluxe Pack executes to the point where it tries to set the VBE register. The register bit then flops high and low (should stay pulled high / 1 until the VBlank erase completes). Initially I thought Salamander 2 used HiRes/8bit mode but TVM remains 000 (standard) and the EWRR shows a frame buffer erase lower right coordinate set of 0x4CC7 (~304x200) when it actually loads. All other Salamander games on the disc use a 320 x 184 coordinate set, 0x50B7, and load fine. Running signal tap shows that the registers which should get blnaked do correctly get blanked on load and FCM/FCT remain set , but then the VBE starts flopping and no further register writes occur. I'm guessing the VDP1 is refreshing the bit to 0 and the actual erase doesn't occur in this case, but that's just speculation.
Expected VDP 1 register state on load: TVM: 000 (Standard) VBE: 0 (VBE off) FBCM: 00111 (Manual Mode, Non-Interlaced) PTMR: 10 (Draw with frame change) (Erase registers as described above) Additionally, differing from the other Salamander games, Local X is set to 0x10, vs 0x20.
Expected during transition: VBE: 1 (stable) All plot/erasure registers zeroed out, everything else the same.
MiSTer does execute code up to the VBE set (you can see the title screen appear for one frame, after the fade to black, like real hardware) but then it hangs with the behavior described above
Zet-sensei
Issue: The game doesn't start at all when choosing it on the main menu.
CD Image: Redump BIN/CUE
Core Version: 20231010