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Pretty sweet indeed! Thanks. Have you ever seen that many smoothly-animated objects on a scan line without flicker? Although the PGM designs are a bit meh, I really like the way they transition between motions except for the way they continuously spin when trapped. Adding another four metatiles for...

Would it play anything like Crystal Mines , Exodus , and Joshua ? If so, those were made on the Color Dreams mapper (#11), which is similar to GNROM (#66). These dynamically convert objects between sprites and background. Another way to allow more metatiles is to let different objects share individ...

lidnariq wrote:You may find Dwedit's demake of Chu Chu Rocket inspiring.

Based on the text, that sounds like the effect I'm after, though I wasn't particularly planning on using sprites for anything other than the player and for side-wall masking. The screen-shot links seemed to be broken, though.

Smooth scrolling is very commonplace on the NES, no need to overthink that aspect. 4-screen (name table RAM on the cartridge) is the easy way out for glitch-free scrolling, but you can also use horizontal mirroring and hide scroll artifacts by masking the sides of the screen (Alfred Chicken, Felix ...

That said, why do you have seven different rocks? (If they're frames of animation, or a theme that changes from level to level, that's what multiple CHR banks are for.) Stationary rock, rock falling out of tile, rock falling into tile, rock sliding left out of tile, rock sliding left into tile, roc...

One of my ambitions is to produce a successor to Boulderdash which features smooth motion, as seen on the Amiga game "Emerald Mine", rather than the tile-at-a-time motion seen on Boulderdash. Preliminary testing on the NES seems promising, though I'm not sure what sort of mapper would be b...

Looking at the pinout for the NES and Famicom, it appears that the console exposes the chip-select and A10 the 2K RAM chip used for nametables, and then expects cartridges to feed those from whatever source would be appropriate. Would there be any difficulty with a cartridge strapping the chip-selec...

Nope. CIC lock doesn't renegotiate after negotiation fails, just endlessly asserts and de-asserts RESET to the CPU and PPU. So CIC-Reset on the cartridge slot is output-only? Bummer. Otherwise, I was wondering about whether there would be any problem setting OAMADDR to a multiple of eight near the ...

The CPU-vs-PPU phase is randomly chosen when the CPU and/or PPU are released from reset. The bug is known to be present in silicon revision G, not be in (rarer) older revisions (A-E), and revision H's properties are unknown. Most famiclones are copies of the revision G PPU and have this bug. (Note ...

All operations involving DRAM reads--and that includes partial-row writes--need to be carefully sequenced. The mechanisms that force a regular sequence of actions may be idle, I understand what you're saying (I know how DRAM works), but I don't see how your explanation is relevant to the specific b...

People here seem to enjoy using C to make 6502 content, so this might be of interest. Camelot have released a new KickC which is a slight variant of C rather than ANSI C to help with optimizing 6502 code Developers of compilers for the 6502 could benefit from seeing how Keil's compiler for the 8051...

That would seem likely to work, but if there's a race condition between the DRAM machinery and the CPU cycles, The DRAM circuitry is completely idle during forced and vertical blanking. ... with the caveat that the (PAL) 2C07 enables DRAM refresh for 50 scanlines before video rendering starts, and ...

I've honestly been wondering why I haven't seen anyone do anything like the Harmony Cart on the NES. Is that extra 600kHz too much? Memory limits? Incompatible with existing library? Two independent buses? Hard part is not just ending up with something ridiculous like this . I don't think a Harmony...

Hm. Thinking closely about the bug, maybe there's a goofy workaround... So, there's two halves to the bug: 1- if you write to OAMADDR, on several CPU-PPU alignments, it'll smear data from one row of OAM DRAM with another. 2- if you leave OAMADDR at a value of 8 or higher, it'll copy the eight bytes...

Since the only sprites would be the player sprite, the score, and the side masks, and only the player sprite would need frequent updates, I was figuring on something like: Sadly OAMADDR is buggy. You can update the first 7 bytes safely, only in order, only by relying on OAMADDR being zero when rend...