First of all, i repeat my signature. my English is poor, so don't be crazy on me if you have a hard reading. And I'll be very happy if you understand what I want to say.
my nes emulator was finished several days ago. it is scanline base now for simpleness.
seems some game works well on it, such as
NROM: Balloon, Mario1...
MMC1: Dragon quest 4(japanese and english version), Zelda1,2...
UNROM: Castlevania1,Rygar, Dragon quest 2(japanese)
MMC3: Metal max(by data east), Shadow of ninja, Mario2
I test it with NESTRESS.NES downloaded from the main page. it is ok for all cpu and addressing mode test, as well as all ppu test except the SPRITE#0 hit. I think it is impossible for scanline base emulator to pass that test because VIRTUAL NES which is scanline base is fail, too.
I aslo test it with S0.NES, and seems it is ok because the result is same as what VNES and FCULTRA except for the mid-scanline effect. Aslo by considering this that I believe my ppu implement is correct as a scanline base emulator and the cause of the failure above is no mid-scanline-hit detect.
following is the problem on some games:
PAC LAND by NAMCOT in 1984-1985, title screen is normal, but after pressing START to start the game, it halt with a black screen.
CUBA SOLIDER by SNK in 1987, when power on or reset, the BG turn white and hold it there. It should display the blue 'SNK' sign then.
when implement CNRON(mapper 3). I test it with DRAGON QUEST 1(japanese) and Adventrue Island 1. both failed.
For dq1, the background trun black(not gray set in reset) but hold it there(should display the title).
For adventure island, the screen keep gray all the time.
UNROM is one of the simplest mapper, and I have check the code(less than 20 lines) again and again but found nothing(aslo read this part of VNES and NESTER source). So I believe that the bug in not in mapper implement, perhaps it is the same one as that holds Cuba Solider.
these are all early games(before 90), so I think that they doesn't use the quirks that not scanline base emulator could handle(and VNES could emulator them all). But with all the games and test result above, I can't figure out which part is the cause of this problem. (Adventure Island must be not relate to APU because even a semi-emulator without sound implement could display the title and start the game).
Please give me some advice for all about this. Thanks !
And Aslo Thank you for read all my broken words patiently.
my nes emulator was finished several days ago. it is scanline base now for simpleness.
seems some game works well on it, such as
NROM: Balloon, Mario1...
MMC1: Dragon quest 4(japanese and english version), Zelda1,2...
UNROM: Castlevania1,Rygar, Dragon quest 2(japanese)
MMC3: Metal max(by data east), Shadow of ninja, Mario2
I test it with NESTRESS.NES downloaded from the main page. it is ok for all cpu and addressing mode test, as well as all ppu test except the SPRITE#0 hit. I think it is impossible for scanline base emulator to pass that test because VIRTUAL NES which is scanline base is fail, too.
I aslo test it with S0.NES, and seems it is ok because the result is same as what VNES and FCULTRA except for the mid-scanline effect. Aslo by considering this that I believe my ppu implement is correct as a scanline base emulator and the cause of the failure above is no mid-scanline-hit detect.
following is the problem on some games:
PAC LAND by NAMCOT in 1984-1985, title screen is normal, but after pressing START to start the game, it halt with a black screen.
CUBA SOLIDER by SNK in 1987, when power on or reset, the BG turn white and hold it there. It should display the blue 'SNK' sign then.
when implement CNRON(mapper 3). I test it with DRAGON QUEST 1(japanese) and Adventrue Island 1. both failed.
For dq1, the background trun black(not gray set in reset) but hold it there(should display the title).
For adventure island, the screen keep gray all the time.
UNROM is one of the simplest mapper, and I have check the code(less than 20 lines) again and again but found nothing(aslo read this part of VNES and NESTER source). So I believe that the bug in not in mapper implement, perhaps it is the same one as that holds Cuba Solider.
these are all early games(before 90), so I think that they doesn't use the quirks that not scanline base emulator could handle(and VNES could emulator them all). But with all the games and test result above, I can't figure out which part is the cause of this problem. (Adventure Island must be not relate to APU because even a semi-emulator without sound implement could display the title and start the game).
Please give me some advice for all about this. Thanks !
And Aslo Thank you for read all my broken words patiently.