Search found 72 matches

by elseyf
Tue Dec 29, 2020 12:23 pm
Forum: SNESdev
Topic: Generate a read signal when accessing 0x8000
Replies: 3
Views: 2968

Re: Generate a read signal when accessing 0x8000

Thanks for the answer. I will look into it and see if ORing the signals works better. Meanwhile, I found out that using a 74HC138 does, for whatever reason, work (maybe it's timing related?). I have a setup where I stream 8-Bit data off a microcontroller to the SNES. It has an output clock that is c...
by elseyf
Tue Dec 29, 2020 9:47 am
Forum: SNESdev
Topic: Generate a read signal when accessing 0x8000
Replies: 3
Views: 2968

Generate a read signal when accessing 0x8000

I have a 74LS139 decoder that is supposed to generate a signal when 0x8000-0xFFFF is read. I use the following setup: 74LS139 ___ ___ | v | VCC -|1 16|- VCC -|2 15|- /RD -|3 14|- /CART -|4 13|- GND -|5 12|- => /RD_CART -|6 11|- -|7 10|- GND -|8 9|- --------- Yet somehow the data does not reach the S...
by elseyf
Wed Jun 12, 2019 11:00 am
Forum: GBDev
Topic: [Tool] gbfix, simple cmd-line tool to fix GameBoy Headers
Replies: 1
Views: 5399

[Tool] gbfix, simple cmd-line tool to fix GameBoy Headers

I have made a small tool to fix the internal GameBoy ROM Header. It's a simple single source file compiled with g++ (or any other c++ compiler).
You can find the tool here: https://github.com/elseyf/gbfix
by elseyf
Wed Jun 12, 2019 10:56 am
Forum: GBDev
Topic: [Homebrew] Bad Apple for the DMG Gameboy
Replies: 3
Views: 8260

Re: [Homebrew] Bad Apple for the DMG Gameboy

How do I compile this to a .gb or .gbc to play it im a fan of bad apple and really want to see this in action Sorry for the belated answer. I have uploaded the assembler I used to compile the binary, you can get it here: https://github.com/elseyf/bass-m To assemble, you just call bass-m with the ma...
by elseyf
Mon Apr 08, 2019 11:05 am
Forum: GBDev
Topic: [Homebrew] Bad Apple for the DMG Gameboy
Replies: 3
Views: 8260

[Homebrew] Bad Apple for the DMG Gameboy

Something I worked on for the past few weeks: https://github.com/elseyf/Bad-Apple-for-DMG-GameBoy Copied from the README: Bad Apple Demo for the DMG GameBoy System - by el_seyf Demonstrates video playing capabilities of the GameBoy The Video is encoded to 160x72 pixels, playing at 15fps and is strec...
by elseyf
Thu Jun 28, 2018 12:27 pm
Forum: SNESdev
Topic: Why no SNES homebrew scene?
Replies: 460
Views: 168708

Re: Why no SNES homebrew scene?

dougeff wrote:Has anyone tried the official WDC C compiler? The website claims it to be free.

http://www.westerndesigncenter.com/wdc/tools.cfm
I tested it some time ago. Unfortunately it produced wrong code when using arrays of chars (if I remember correctly). I gave up on it assuming more errors were waiting.
by elseyf
Sun Jan 28, 2018 1:35 pm
Forum: General Stuff
Topic: What is the minimum amount of instructions you need in a CPU
Replies: 16
Views: 4715

Re: What is the minimum amount of instructions you need in a

I guess you could have a CPU only working with basic MOVE instructions, mapping the ALU in memory. It would only need additional hardware to process conditionals. This was done on x86, see here . Of course there are many considerations on how to design the CPU in order to know which instructions you...
by elseyf
Mon Aug 07, 2017 9:10 am
Forum: Homebrew Projects
Topic: Project "obituary" - T-rex riding game (gfx and bgm inside)
Replies: 1
Views: 3210

Re: Project "obituary" - T-rex riding game (gfx and bgm insi

Said project source can be found here: https://github.com/elseyf/Rex-Runner-NES
It does contain some useful code, mainly packed into macros, so anyone can look into it and extract anything useful. No license, no worries
by elseyf
Wed Jul 19, 2017 2:21 pm
Forum: NESdev
Topic: ca65 feature is somehow "illegal" [RESOLVED]
Replies: 8
Views: 2896

Re: ca65 feature is somehow "illegal"

I just looked into it, when downloading the windows snapshot from sourceforge you do get a recently compiled snapshot (mine is from Jul 18, 2017). --version flag result in following output: ca65.exe V2.16 - Git 6002e59 make sure to use this link https://sourceforge.net/projects/cc65/files/latest/dow...
by elseyf
Sat Jun 03, 2017 3:55 pm
Forum: SNESdev
Topic: Keeping your eyes on the size
Replies: 11
Views: 9457

Re: Keeping your eyes on the size

Nice demo!
I wrote a BF Interpreter for SNES using 1kB in total for a contest held some time ago: SNESF1k
by elseyf
Tue Mar 14, 2017 2:25 am
Forum: NES Hardware and Flash Equipment
Topic: Adding features to discrete mapper with multipurposed CIC
Replies: 98
Views: 47269

Re: Adding features to discrete mapper with multipurposed CI

This sounds interestening. Is the CIC Firmware going to be open source, and if so, is it supplied in a manner that it could be easily worked into a custom program running on the mcu? I see this as a free means to do some basic DRM protection for a new homebrew game, the mcu could interface some addi...
by elseyf
Sun Jan 15, 2017 1:47 pm
Forum: NES Hardware and Flash Equipment
Topic: Arduino based projects for the nes?
Replies: 19
Views: 5651

Re: Arduino based projects for the nes?

If you need some project idea for an Arduino, you could try and build either a wireless Controller, or a Controller to USB adapter. I am currently on building the first; a wireless SNES Controller, with Mouse support using a laser mouse (I found a PS/2 Mouse that uses a laser for movement detection)...
by elseyf
Tue Dec 13, 2016 12:40 pm
Forum: NES Hardware and Flash Equipment
Topic: GreenPAK mapper golf
Replies: 27
Views: 9889

Re: GreenPAK mapper golf

I see, then the greenpak is really only suited to replace the gluelogic NES mappers, or implement your own "not-so-comlicated" mapper. It doesnt seem to be suited for for the LO/HIROM switch either, as you pointed out, it might be just more efficient to remap all data on the ROM, so that a single mu...
by elseyf
Tue Dec 13, 2016 9:05 am
Forum: NES Hardware and Flash Equipment
Topic: GreenPAK mapper golf
Replies: 27
Views: 9889

Re: GreenPAK mapper golf

I have got several questions: Is there enough logic on a greenpak to support a full MMC1 replacement? I do see that MMC3 wouldn't be possible due to available resources, but how about using several, how many would be needed? And is there a way to synthesize logic from code, or do you have to use the...
by elseyf
Tue Dec 13, 2016 5:13 am
Forum: SNESdev
Topic: 16-bit pointers on the SPC-700
Replies: 17
Views: 7216

Re: 16-bit pointers on the SPC-700

I have written some custom bootloader for the SMP. Maybe the code will help. The SMP can do indirect 16 Bit addressing, you would need to write something like this: ldy ($xx),y Where $xx is in the page0 memory space (I am not sure it needs to be page0 or page1, but I guess it is like the 6502, where...