00mjk / fpgbasharp

C# GBA Emulator

FPGBASharp - C# GBA Emulator

Reference plattform for my FPGA GBA implementation.

Attention

This emulator is not made for good playing experience, but as a research project! While it can play almost every game, it has quiet some shortcomings.

• Programming is not as object oriented as it should be with C#, mainly using public, static classes and direct access to class members. This is due to the fact that quick research was the goal and not maintainability
• Everything in UI is done for research only, not for better playability.
• Speed is very low. You need a high end processor to be able to reach full speed
• Some features are only implemented to the point they are understood and can be implemented in FPGA logic
• Windows only

Features

• all videomodes including affine and special effects
• all soundchannels
• saving as in GBA
• Savestates(compatible with FPGA implementation)
• FastForward - Speed depends on your system
• adjustable CPU Under/Overclocking
• Flickerblend - turn on for games like F-Zero, Mario Kart to prevent flickering effects
• Cheats
• Color optimizations: shader colors
• Tilt
• Solar Sensor
• Gyro
• Affine Layer (Mode 7) double Resolution
• Affine Layer (Mode 7) 2x2 Antialiasing

Features missing

• Fixed Input Keys(see below)
• Asynchronous screen update(tearing!)
• No support of CPU Pipeline prefetch(Classic NES games don't work)

Input

• DPad - Cursor Keys
• A - A (D for Turbo fire)
• B - S (F for Turbo fire)
• L - Q
• R - W
• Start - X
• Select - Y
• Quicksave - F5
• Quickload - F9
• FastForward - Space
• Tilt - K/L/I/O
• Gyro - V/B/N/M
• A+B+Start+Select(Reset) - R

Bios

Opensource Bios from Normmatt is included, however it has issues with some games. Original GBA BIOS can be used to replace the gba_bios.bin

Accuracy

(Status 03.02.2020)

Attention: the following comparisons are NOT intended for proving any solution is better than the other. This is solely here for the purpose of showing the status compared to other great emulators available. It is not unusual that an emulator can play games fine and still fail tests. Furthermore some of these tests are new and not yet addressed by most emulators.

There is great testsuite you can get from here: https://github.com/mgba-emu/suite It tests out correct Memory, Timer, DMA, CPU, BIOS behavior and also instruction timing. It works 100% on the real GBA. The suite itself has several thousand single tests.

Testname	TestCount	FPGBASharp	FPGBA FPGA	mGBA	VBA-M	Higan
Memory	1552	1552	1552	1552	1338	1552
IOREAD	123	123	123	116	100	123
Timing	1660	1554	1554	1540	692	1424
Timer	936	339	445	610	440	457
Timer IRQ	90	65	65	70	8	36
Shifter	140	140	140	140	132	132
Carry	93	93	93	93	93	93
BIOSMath	625	625	625	625	625	625
DMATests	1256	1248	1248	1232	1032	1136
EdgeCase	10	1	3	7	3	1
Layer Toggle	1	pass	pass	pass	pass	fail
OAM Update	1	fail	fail	fail	fail	fail

A complex CPU only testuite can be found here: https://github.com/jsmolka/gba-suite

Testname	FPGBASharp	FPGBA FPGA	mGBA	VBA-M	Higan
ARM	Pass	Pass	Fail	Fail	Fail
THUMB	Pass	Pass	Fail	Fail	Fail

Bugs

Bugs can be commited, but have very low priority if they don't occur in the FPGA version. Please don't report feature requests for UI or Input handling, as this is no goal!