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Topics - Dr. Floppy

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Programming / SMB1 = Over 99% NMI Routine
« on: October 25, 2015, 06:13:33 am »
99.99729%, to be exact. (And that doesn't count the tile screen layout data stored in CHR-ROM.)

The game starts up at $8000 and proceeds to an infinite loop at $8057. It's plucked out of this loop by the NMI Routine at V-Blank, wherein every other aspect of the game is finagled. Once the NMI Routine ends (usually around scanline 112), the RTI takes the game back to the infinite loop (thus negating the need for the usual AXY-juggling which bookends typical NMI Routines).

Is there any particular reason the OP's might have done it this way? Do any other NES games exhibit this odd arrangement?

Personal Projects / Friday the 13th (NES) Oziak
« on: September 18, 2015, 09:13:03 pm »
A playable/enjoyable rendition of Friday the 13th is long overdue. Stuff fixed thus far:

* The rock weapon no longer arcs.
* Jason no longer kills you in 4 hits.
* The counselor stats are tweaked so none of them suffer from Polio.

Also slated, pending resumed Adderall™ functionality:

* Simplified, intuitive map system.
* No more warped space transition-points (forest).
* Medicine actually heals you.
* A formal armory, preventing weak weapons from auto-replacing better ones.
* Use weapon while jumping!  :o
* JasonTracker™

What'd we miss?

Personal Projects / Ghetto Warrior (Hack of Dragon Warrior/Quest 1)
« on: June 02, 2015, 07:07:19 pm »
My next official project, already underway, is an orchids-out Expansion / Total Conversion of the original installment in the Dragon Quest/Warrior series. It follows the adventures of an urban youth as he travels to various locations across the IRL continental United States. So far, the mapper has been upgraded to MMC5 and the ROM likewise expanded. I'm also using the 8x16 sprite option for larger characters.

The time has come for a specific decision to be made. My rotoscoped Overworld came out to 5488 x 2912 pixels, which equates to 343 x 182 in-game "squares". (The player travels roughly 9½ miles every time he moves from one square to another.) I can go with this, or I can go with a smaller, less formal "overworld" that merely serves as the central hub connecting various regions together. The advantage of this latter option would be to allow even greater resolution of the regions themselves, up to and including accurate rivers and freeways. It also dovetails with the plot, which envisions a Balkanized America circa 2020-ish. 

I split the continental U.S. up into various sub-regions in a manner that made sense both culturally and circumscribed-within-rectangle friendly. I wound up with 17 new rump countries, six of which used to be singular states. Only once did I make a division within prior state lines.

Thoughts? Suggestions/corrections??

The Legend of Iowa

Hack of: The Legend of Zelda (NES)
Type: Total Conversion
Author: Dr. Floppy
In Association with:
Production: 2008-2015
Get It!: The Legend of Iowa, Version 1.13


* Original Storyline
* New Overworld
* 18 New Underworld Levels
* New Soundtrack
* Never-before-encountered Enemy Combinations
* New Graphics
* New Enemies / Bosses
* More Colorful Layouts
* Tons of New Secrets!
* Expanded ROM & Upgraded Submapper
* Background Animations
* A Fourth Sword!!! Absolutely nothing of interest.

Known Issue with NEStopia & PowerPak: If the game "blacks out", press Select on Joypad #2 to force Screendraw.

Another Known Issue: I intentionally resurrected the "Infinite Iowa Piece" glitch, so as to allow people to reclaim what's rightfully theirs and then some.

The old Death Counter has been retasked as an Iowa Piece Counter, hopefully resolving this dastardly string of problems once and for all.

Programming / BNE/BEQ --> BZC/BZS
« on: February 13, 2015, 09:10:25 am »
It occurred to me the other day that the Branch on iNEquality & Branch on EQuality commands are more accurately described as Branch on Z-flag Clear & Branch on Z-flag Set (respectively). Anybody know why Peddle/Mensch went with the BNE/BEQ terminology instead of the conceptually-clearer (and cooler looking) BZC/BZS?

ROM Hacking Discussion / Silencing Pulse Channels (without using $4015)
« on: November 11, 2014, 12:28:17 pm »
I'm finalizing the Legend of Iowa soundtrack, and have come across an odd effect with respect to the Pulse-1 channel. The original game didn't have "hard" rests, merely the "soft" variety wherein a melodic channel was allowed to fade away into nothingness until a new frequency was issued. I recoded the rest-handler to differentiate between soft and hard, the latter getting a nice big #00 sent straight to $4000 / $4004 to silence the prior pitch.

However, I'm now getting these weird high-pitched clinking noises on Pulse-1 (haven't tested Pulse-2 yet) whenever a hard rest is encountered by the music engine. They're extremely brief, but distracting nonetheless. I've found that I can adjust the severity by altering the value that gets sent to $4001 upon hard-rest, but nothing seems to completely eliminate it.

Anyone know what value can be fed to $4001 (and $4005, for that matter) to instantly silence the Pulse Channel? [I don't want to play around with $4015, as that'd likely annoy the DPCM sampler.]

Gaming Discussion / Favorite Super Mario Kart (SNES) Tracks?
« on: March 10, 2014, 02:09:31 am »
Research for future hack...  :thumbsup:

ROM Hacking Discussion / SNROM --> SKROM?
« on: May 22, 2011, 10:29:02 pm »
What happens if someone (NES Reproductions) tries to update a SNROM game using a donor cart *of* that game, with a ROM image of a hack that just happens to utilize CHR-ROM (which SNROM doesn't support)?

Would this hack only work on SKROM donor carts?

Programming / Mapper Project: MMC5 w/ 4-screen Mirroring
« on: May 10, 2011, 09:09:51 pm »
About a year ago, I inquired as to whether or not any MMC5 games utilized 4-screen mirroring?,11050.0.html Of course, the answer was no: only two NES titles utilized this mirroring method, and neither of them were among the eight MMC5 games released in the States. It was also established that 4-screen mirroring probably wouldn't be the best bet for my "Alpha" project, which utilizes bidirectional scrolling in only one dimension at a time (if at all).

However, the estimable Mr. Disch did allude to the technical possibility of adding 4-screen mirroring to an MMC5 cart, effectively creating a special version of that mapper. Without going into interminable details, I now have legitimate use(s) for such a creation. However, my pre-production research has unearthed a number of queries which I now submit:

1) Is there anything about the internal MMC5 layout that would prevent or prohibit the addition of extra RAM for 4-screen mirroring?

I figured I'd study the internals of Gauntlet or Rad Racer 2 to see how the extra RAM linked up to everything, then apply those changes to an MMC5 donor cart. By the looks of this image (Gauntlet's board), there is no direct interfacing between the MMC3 chip and the extra RAM itself:

2) What happens to the native 2k on the NES itself? I'm led to believe that the cart-based RAM (8kB for both Gauntlet and RR2, but A12 is tied to ground making it effectively 4 kB) overrides the native console RAM when it comes to Name/Attribute Tables. So the native stuff just sits there looking pretty...

3) How much interference should I expect from the MMC5's pre-existing ExRAM? Obviously, $5104 Modes 0 and 1 are out the window, but since modes 2 and 3 utilize the CPU space at $5C00-5FFF, I'm hoping that they can stick around.

4) Name Table Mapping at $5105: Assuming Mode 2 or 3 is set at $5104, would setting $5105 as #$A4 allow the extra screen data to register in NT's 2 and 3? Or would the MMC5 just keep everything from $2800-2FFF zeroed-out?

And, assuming all of the above is resolved and the project is completed successfully:

5) Do I submit the documentation to Kevin Horton or Marat Fayzullin?

6) Can I pick my own iNES mapper number? (Which ones are left, anyway?)

ROM Hacking Discussion / MMC5 NES games Released in North America
« on: May 02, 2011, 01:00:59 pm »
So far, I've got:

Bandit Kings of Ancient China
Castlevania III
Gemfire (aka Royal Blood)
Laser Invasion (aka Gunsight)
Nobunaga's Ambition 2
Romance of the 3 Kingdoms II
Uncharted Waters

Did the USA really only get eight of these things?

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