Daedalus and the PSP Slim + Lite

Daedalus and the PSP Slim + Lite

October 1st, 2007, 22:40 Posted By: paintball1119

strmnnrmn updated his blog about his thoughts on making a daedalus for the psp slim only:

A number of people have been asking if Daedalus will support the PSP Slim and Lite (PSP-2000), and if it does, if it will take advantage of the extra 32MiB RAM to improve the speed of emulated roms.

I am planning on supporting 3.xx firmware, but not until I have a PSP with suitable firmware which I can test with directly. People will probably end up compiling the Daedalus source for 3.xx (and they're welcome to), but until I can verify everything directly myself these will have to remain 'unofficial' builds. If there is strong demand for a 3.xx version of Daedalus then I'll consider setting up a donations page with the aim of buying a Slim and Lite for development.

As for the additional 32MiB RAM that the PSP-2000 provides, it's unlikely that this will provide for faster emulation. I've spent a lot of time reducing Daedalus's memory requirements so that it runs comfortably in the 32MiB that the PSP-1000 provides (it's actually a fair bit less than this when you take out OS overheads etc.)

There are only two main areas of the emulator that would benefit from an increase in cache size. The first is the texture cache, which is only used when video memory is exhausted. I fixed a few bugs with this months ago which means that very few roms ever have to place textures in system memory.

The second place that would benefit from a cache increase is the ROM cache. In order to support roms larger than the PSP's system memory, I dyamically map pages of the ROM into the PSP's RAM on demand (rather like virtual memory on PCs.) If a page of the ROM that is requested isn't in the cache, I have to pause emulation as I load it from memory stick. Currently this cache size is 2MiB. It could be increased up to 32MiB which would fit most N64 roms comfortably, and would entirely eliminate paging while the emulator is running. This might give a small speedup, but I don't believe this is currently a significant issue even with the tiny 2MiB cache that is currently in use.

Increasing the dynarec buffers would be very unlikely to provide a speedup, as I've yet to see a rom where they fill up before they are flushed for some other reason (typically instruction cache invalidation.)

So in summary, yes, I will support the PSP Slim and Lite at some point, but no, it's unlikely to offer much of an improvement over the PSP-1000s (other than being slimmer and lighter, obviously