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Sega Master System for MiSTer
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Light Phaser SNAC drift compared to real hardware/MegaSG + DAC #162

Open YLFAndy opened 1 year ago

YLFAndy commented 1 year ago

Description: The light phaser shows a pronounced drift via SNAC on the SMS core. The drift appears in all games and is more pronounced on the left hand side of the screen, and is non-existent on the right hand side (linear reduction in drift with X axis). Panasonic BVM RGB with composite sync, 17" and Toshiba 20AF43 both display the issue, Toshiba over straight composite as well.

Prerequisites: A MiSTer and appropriate SNAC adapter, Sega light phaser, CRT TV. SNAC enabled and jumpered properly on the I/O board.

Repro Steps:

  1. Launch a game with easily viewable drift. Example: Gangster Town (The name entry screen is a static grid).
  2. Fire the phaser to start the game.
  3. Fire the phaser at the first column of letters at close range.

Result: The phaser registers far to the left of the desired target point.

  1. Fire the phaser at the last column of letters at close range.

Result: The phaser registers very accurately to center.

Expected result: The phaser should retain accuracy along the X axis over SNAC.

Other notes:

Other systems tested -

Original Master System Power Base hardware (NTSC, NA, Composite) - Result: Consistent accuracy across the X axis.

MegaSG + DAC + SOG - Result: Consistent accuracy across the first 80% of the X axis, slight drift right and down on the right edge of the screen.