How insistent are you about "all means"? Would you accept, for example, a game where the NTSC cartridge costs $40 but the PAL cartridge costs $50 because it contains a more advanced mapper or more RAM on the cartridge, such as an upgrade from UNROM/UOROM to MMC3, from no WRAM to WRAM, or from CHR ROM only to CHR ROM and CHR RAM, solely to implement means of hiding the seam? Would you be willing to wait for the developer to see how many copies a game sells in NTSC markets and only a year later make a PAL version reengineered to hide artifacts if the sales quantity warrants? And if so, how many others like you would be willing to wait and/or pay just to hide the seam?NewRisingSun wrote:I would recommend not assuming that the top and bottom eight scanlines are shown --- so don't put anything important there --- but not assuming that they are not shown either. If you can avoid showing garbage in any part of the screen, then by all means, do avoid it.
Why an upgrade from UNROM/UOROM to MMC3 might be necessary:
The means of hiding artifacts means requires access to a programmable interval timer (PIT) or fine-grained CHR bank switching, such as switching to the bank containing CHR data for sprites that have been software-clipped at the top.
Why adding WRAM might be necessary:
Additional scratch space to hold CHR data for sprites that have been software-clipped at the top.
Additional scratch space to hold additional rows of cached decoded tilemap data.
Why an upgrade adding VRAM might be necessary:
Hold CHR data for sprites that have been software-clipped at the top for display.
Hold additional nametable data for 4-screen VRAM.
Hold additional nametable data for status bar.