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ekeeke / Genesis-Plus-GX

An enhanced port of Genesis Plus - accurate & portable Sega 8/16 bit emulator
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Border Left/Right, Full (256px width mode) should not be 284px width #483

Closed SopTheSop25 closed 1 year ago

SopTheSop25 commented 1 year ago

@ekeeke the border left/right, full overscan area (256px width mode) should not be 284px width, it should be 280px width SG-1000/Master System has entire overscan of 280x240 on NTSC, 280x288 on PAL (Also on Genesis/Mega Drive with 256px width mode) Game that has resolution of 256x192, 256x212, 256x224, 256x240 and 256x288

284px width 284x240 Alex Kidd in Miracle World SMS 284x240 Mega Bomberman MD 284x240

280px width (real hardware) 280x240 Alex Kidd in Miracle World SMS 280x240 Mega Bomberman MD 280x240

ekeeke commented 1 year ago

This is incorrect. Left and right borders are respectively 13 and 15 pixels wide so 256 + 13 + 15 = 284 pixels in total. This is described precisely in TMS99xx VDP programmer manual and has been verified to be the same on real hardware with Master System and Mega Drive VDPs.