![]() Variable names did not always match the docs.Has a lot of literal values for masks and shifts making it unclear what is being processed.If you read the patents the system seemed reasonably straightforward but the code not so much. The FreeDO/4DO VDLP emulation was not the best. It has programmable functions which provide a number of features including: managing CLUTs (color lookup tables), performing optional horizontal and vertical interpolation (upscaling from the internal 320×240 framebuffer to 640×480), managing background color, integrating secondary video data streams, etc. The 3DO has a fairly advanced video display line processor. With the filesystem API the host storage device could be used directly allowing easier sharing and backup of save games and offering more space than a real system could have. The DSP is probably 1/3 of the CPU cost to emulation so HLE could make a big impact there. Meaning that each of these programs could be statically re-implemented in C instead of using the current interpreter. The DSP never got a development kit so most (all?) games use standard programs provided by The 3DO Company. In the future a number of other functions would be interesting to replace such as the DSP and filesystem APIs. You can see what games use these functions on the 3DO Development Repo site. The option can be toggled in real time making comparison easy. Games that make heavy use of the matrix hardware run a few FPS faster on lower end systems such as the XU4. So we’ve added a new, optional, HLE mode that replaces the emulated hardware or software matrix functions with native fixed point calculations performed in straight C. So we know that improving the matrix arithmetic situation could help lower end systems struggling with the LLE and it should also be simple to ensure accuracy. ![]() While reworking MADAM emulation in the past it was recognized that the OS could and would check the revision of the MADAM chip and had a fallback to software based matrix functions if it recognized it was running on a prototype system without the matrix hardware and that for some games there was a slight speed increase when switching between the hardware emulation and the software routines. This is used in a number of 3D games and called regularly. The MADAM graphics co-processor has a set of hardware accelerated 16.16 fixed point matrix arithmetic functions. Some of these functions are somewhat complicated but one set of SWI calls were a perfect candidate for HLE: the matrix arithmetic functions. This makes catching and overriding these calls very easy when combined with knowledge of the ARM procedure call standard.Ĭatching and overriding some or all of the OS functions would theoretically improve performance and/or enable advanced features. ![]() Many of the core OS functions are called via the ARM SWI (software interrupt) instruction. The ROM OS is pretty thorough but ultimately a bootloader and bootstraps the environment before handing control off to the software on the CDROM. The OS is present in the system’s ROM but also included on each CDROM. The OS and most/all software for the platform is written in C and compiled using the Norcroft ARM toolchain from that era. It has preemptive multitasking, threading, high level memory management, dynamic loading of “folios” (libraries), IPC, IO APIs, and general abstractions to much of the hardware. The 3DO was ahead of its time in a number of ways. Here’s an overview of some of that work and plans for the future. After a year’ish break I’m back and have been focusing on accuracy and some experimentation in HLE (high level emulation). After fixing a VSYNC issue that many had complained about I ended up almost completely refactoring the code and adding a number of features. RetroArch offers a Quick Menu accessed by pressing + which can be used to alter various things like RetroArch's basic settings, core options and per-core controller mapping.About two years ago I more or less adopted the libretro 4DO core. Map controller inputs to light gun inputs. Increasing this can reduce crackling/cutting out, at the cost of delayed audio. ⇒ OpenGL gl, GLCore glcore, Vulkan vulkan. GLcore is a newer version of OpenGL, but doesn't have as much coverage as OpenGL. Vulkan may not work for every core/hardware configuration. In general, Vulkan is the preferred (and more performant) API, but certain hardware may favor OpenGL more. ![]() Settings that apply to all cores of this emulatorĬhoose which graphics API library to use. Write themes for batocera-emulationstation.Redirect upgrades from any board to my own builds.Latency reduction and optimizing performance.Raspberry Pi: Add power buttons/switches.Sync files across multiple devices (Syncthing).PCman built-in file manager (for Xorg-powered devices).
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