What command is actually executed by the operation code 0x6b?
The meaning I saw on the website is as follows:ARRAND oper + RORThis operation involves the adder:V-flag is set according to (A AND oper) + operThe carry is not set, but bit 7 (sign) is exchanged with...
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SMB emulation issues
Hi all,That's my first post here.... I've being writing a NES emulator on my spare time for a while... so far I've got a lot of stuff ready: CPU Emulator, ROM Loader, GUI, Palletes, basically I do my...
View ArticleQuestion about documentation and BUS
Hi folks,The question is: does /ROMSEL (on the cartridge slot) is LOW (active) even if the CPU is not reading the ROM? ($8000–$FFFF - this is, M2 LOW and A15 HIGH)Just to explain from where my...
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Difference between SW# and WE#
Hello,What if the difference between SW# and WE# pins function ?MX29LV640EBTI-70G Datasheet shows me WE# for pin 11 and on schematic it's named like SW# Statistics: Posted by Kayumba — Mon Jun 03,...
View ArticleNES power supply a bit hot even when unused
Hi,It may be a dumb question, just wanna be sure i don't damage my hardware.I noticed my french nes power supply is a bit hot, even when unused, when it's plugged on.Is it a normal behavior of the NES...
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Difficult-to-dump multicart
I am having difficulty dumping this multicart:It seems to have a data latch with bus conflicts, and has both 16 KiB and 32 KiB NROM games on it.Statistics: Posted by NewRisingSun — Wed Jun 05, 2024...
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Strange multicart with 6 memories
Strange cartridge with 99% of the PCB surface occupied by chips and one epoxy-blob mapper.//top-components.jpg//bottom.jpgFirst look at the pcb reveals that /IRQ (pin 15) is not connected at all, so...
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After Burner Mapper 68 Discrete
hi folks i have a rarest copy of After Burner in discretes ICs, but It have two PAL16L8 and a Lot of 74HC IC. I want make a reverse engeneering and i need Help to dump for rebuild After dump.If work i...
View ArticleUsing a background as a fake game character
As far as I understand things, if I have a bunch of tiles in a background tileset, I can display whichever of those tiles at whatever position on-screen in any given frame, so I could store different...
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How does the PLA instruction work exactly?
Hi, sorry if this is a noob question but this is my first time developing an emulator/working with the NES.I am currently writing the CPU part of the emulator and am using the nestest rom to do so,...
View ArticleMibiNESTools: Create CHR files and nametables easily.
I found that that a lot of editors for CHR files and nametables suck: Tilemolester is unstable (on linux at least), and Lightbox is very primitive.That's why I started making a tool that is powerful,...
View ArticleMaking emulators touch-aware through breakpoint files
I was reading through Apple's guideline for touch controls in games for iOS. It offers suggestions that could improve emulators designed for any desktop or mobile platform.Apple's guideline for...
View ArticleCan I force ca65 to error if a charmap character is not mapped?
So, let's say I have a charmap mapping like this:Code: .charmap $30, $00 ; 0.charmap $32, $02 ; 2And I then write code like this:Code: ldy #'0'sty PPUDATAldy #'1'sty PPUDATAldy #'2'sty PPUDATAThis...
View Article8-bit random number generator combining LFSR and LCG
A few days ago, I learned about a period 256 pseudorandom number generator by foobles that combines aspects of a linear feedback shift register (LFSR) and a linear congruential generator (LCG).In...
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Donkey Kong for PC :D
Hello everyone This time I want to share with you my new game for PC programmed in Java in my free time.Classic Donkey Kong DonkeyKong_Java.zip252KBI hope you will enjoy it.I start it 2 weeks ago and...
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NES PCB help
Hello,I bought a NES a couple of months ago in a attempt to restore it since it was broken, and in the attempt I had to take off the CIB lock out chip off the board as when I tried to power it on it...
View ArticleHelp with 60Hz hard mod on PAL 1-chip SNES.
I want to mod my 1-chip PAL SNES for "permanent" 60hz video output. Doing this process on an original SNES revision seems to be well-documented, but info on doing with a 1-chip revision seems to be...
View ArticleTop row of pixels of each sprite is wrong color
Hi all! First time poster here. Hoping y'all can provide some insight.There's an issue in my project (Mapper 30) where the top row of pixels of each sprite is the wrong color. In case it's relevant,...
View Article4-in-1
have this rom 4-in-1Monster In My PocketSnow BrosBubble Bobble 2Super Contra 7Statistics: Posted by TheBoxGamePL — Sun Jun 16, 2024 11:11 am — Replies 0 — Views 76
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Address decoder - does this have any sense?
I am working on guessing connections of one particular cartridge.This cartridge has two write registers (74161, 7474), one read register (74244), and RAM memory.When those elements need to be enabled...
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