Search found 507 matches

by Bananmos
Thu May 16, 2019 3:06 pm
Forum: NES Hardware and Flash Equipment
Topic: Modulator of french NES with semi-RGB output
Replies: 8
Views: 11076

Re: Modulator of french NES with semi-RGB output

Is this an SNES-style port -- are they compatible? No, neither geometry nor pin position. Physically it's more shaped like the FDS data cable. I have one of these NES's and seem to recall that - to my surprise - the cable is not just similar to the FDS, but fitted perfectly. Maybe not much of a sur...
by Bananmos
Mon May 06, 2019 6:23 am
Forum: Homebrew Projects
Topic: Ruby Runner motion test
Replies: 46
Views: 27920

Re: Ruby Runner motion test

For playback rate $C, we have a period of $06A = 106 cycles on NTSC. This means 106*8 = 848 cycles until an interrupt hits. Or ~7.46 scanlines. This leaves us with 0.54 of a scanline, to do the work in our IRQ handler, or 61.3 CPU cycles. This should be plenty of time to enter the IRQ handler, writ...
by Bananmos
Mon May 06, 2019 3:34 am
Forum: Homebrew Projects
Topic: Ruby Runner motion test
Replies: 46
Views: 27920

Re: Ruby Runner motion test

I sort of struggle to see what MMC2 / MMC4 would provide that a scanline IRQ couldn't, except for a modest amount of saved CPU cycles. Using a scanline IRQ would require a relatively complex mapper chip. While MMC2/MMC4 are somewhat fancy, a game designed for MMC2 could be readily adapted for a dis...
by Bananmos
Mon May 06, 2019 3:18 am
Forum: Homebrew Projects
Topic: Ruby Runner motion test
Replies: 46
Views: 27920

Re: Ruby Runner motion test

And if you can live without the DMC channel in your game's music, you may not even need a mapper-based IRQ, but could use the DMC channel's IRQ as explained on the wiki: https://wiki.nesdev.com/w/index.php/APU_DMC I'm pretty sure you'd lose a lot of CPU time if you used this trick multiple times pe...
by Bananmos
Sun May 05, 2019 3:36 pm
Forum: Homebrew Projects
Topic: Ruby Runner motion test
Replies: 46
Views: 27920

Re: Ruby Runner motion test

I think MMC2 and MMC4 could easily almost double the number tiles, by having each row start with either a "switch to set 0" or "switch to set 1" tile. Going from 64 tiles to ~120 would be a big improvement. Not sure if I'd find myself wanting more than 120 tiles, but I can easily see 64 as being in...
by Bananmos
Sun May 05, 2019 2:42 am
Forum: General Stuff
Topic: Nintendo cease&desist on a C64 port of Super Mario Bross
Replies: 31
Views: 25067

Re: Nintendo cease&desist on a C64 port of Super Mario Bross

supercat wrote: The C64 used 1000 bytes to store character data and 1000 bytes of color attributes;
Oh yes, I totally forgot about the color attributes. That makes the VSP trick even more crucial for this port.
by Bananmos
Sat May 04, 2019 4:34 pm
Forum: General Stuff
Topic: Nintendo cease&desist on a C64 port of Super Mario Bross
Replies: 31
Views: 25067

Re: Nintendo cease&desist on a C64 port of Super Mario Bross

As far as I know it, on the C64, there are registers for a fine scroll of only 0..7, after which point games normally have to manually shift the entire screen data by 1 column. Exactly. The 8-pixel scroll helps a lot, but on an NTSC system in particular, the shifting of the entire screen willl take...
by Bananmos
Sat May 04, 2019 4:18 pm
Forum: General Stuff
Topic: Nintendo cease&desist on a C64 port of Super Mario Bross
Replies: 31
Views: 25067

Re: Nintendo cease&desist on a C64 port of Super Mario Bross

Abobo big Adventure won't be on Nintendo's radar since it's not own by them but technos Japan (now defunct and own by Arc System) and isn't a trademark of them either. Super Mario bros, on the other hand, they own. As to why is Super Mario Crossover was not affected, my guess would be it's a rom ha...
by Bananmos
Fri May 03, 2019 5:04 pm
Forum: General Stuff
Topic: Nintendo cease&desist on a C64 port of Super Mario Bross
Replies: 31
Views: 25067

Re: Nintendo cease&desist on a C64 port of Super Mario Bross

I actually learned a new fact about the C64 from this: Apparently the Super Mario port uses "VSP", a hardware quirk that allows you to scroll the entire screen, just like on the NES, by incrementing / decrementing the 3-bit scroll on an exactly timed cycle outside the visible screen. I can imagine t...
by Bananmos
Fri May 03, 2019 4:40 pm
Forum: NES Hardware and Flash Equipment
Topic: $4016 D3 and D4 ports on Famicom
Replies: 27
Views: 21763

Re: $4016 D3 and D4 ports on Famicom

So to my delight, it appears that NES-004E controllers *do* work on an NTSC NES when plugged into a NESE-034 fourscore. And they are the standard ones here in the UK, so easy to buy. I just didn't happen to have many of them, since my PAL NES's were from Sweden, and I then got NTSC ones - both of wh...
by Bananmos
Thu May 02, 2019 5:36 pm
Forum: NES Hardware and Flash Equipment
Topic: $4016 D3 and D4 ports on Famicom
Replies: 27
Views: 21763

Re: $4016 D3 and D4 ports on Famicom

So I've just tried Micro Mages, and realised to my disappointment that both my Fourscores are PAL variants and won't play it at all on my NTSC NES. And judging by the thread at Nintendo age, no one has figured out a solution for how to mod the fourscore either. I'd like to avoid any more delay in ge...
by Bananmos
Wed Apr 10, 2019 4:55 pm
Forum: NES Hardware and Flash Equipment
Topic: RGB Mod streaming question
Replies: 20
Views: 12879

Re: RGB Mod streaming question

The NESRGB mod is a very neat mod, and combined with the OSSC it's allows you to get 5x scaling on a HDTV, which is a nice feature - if you can accept that the vertical resolution will be cropped to 216 pixels. The one downside with it though, is that it doesn't correctly emulate the palette entry p...
by Bananmos
Wed Apr 10, 2019 4:28 pm
Forum: NES Hardware and Flash Equipment
Topic: PowerPak mapper 30 implementation
Replies: 67
Views: 69676

Re: PowerPak mapper 30 implementation

Looks like PowerpakMapper30_v3 came with a pretty bad bug, courtesy of nesasm, which due to its daft addressing syntax had turned the final "jmp ($FFFC)" into a plain "jmp $FFFC". Strangely, Troll Burner, Black Box Challenge and the test ROM all seemed to boot fine with this bug in-place. But the B...
by Bananmos
Tue Apr 02, 2019 3:45 pm
Forum: NES Hardware and Flash Equipment
Topic: PowerPak mapper 30 implementation
Replies: 67
Views: 69676

Re: PowerPak mapper 30 implementation

I'm curious how FDS saving was implemented... though I suppose the modified BIOS could just write out the file any time it changed. Well, I noticed when digging through the powerpak module sources that the code path for FDS saving has the disk in the upper 256kB (=space for 2 double-sided disks) of...
by Bananmos
Tue Apr 02, 2019 1:51 pm
Forum: NES Hardware and Flash Equipment
Topic: PowerPak mapper 30 implementation
Replies: 67
Views: 69676

Re: PowerPak mapper 30 implementation

Oh.... so for mapper 30 the save file is just a placebo and it just writes directly back to the .NES? (...and consequently loads its save from there too?) Will writes to everywhere work (despite note being saved) or is only the low 8k writable? Writes anywhere will work, and the whole 512kB PRG *is...