On 7/27/06, Renich Bon Ćirić <[EMAIL PROTECTED]> wrote:
James Courtier-Dutton wrote: Renich Bon Ćirić wrote: Well, everybody's telling me that Akai's OS is something else. Realtime stuff and 2 or 3 engines and DSPs to manage. Besides, we have to support akai's native file formats, like PROGRAM, MULTI and Sequence. I really don't know why... I'm just hearing what everybody says. You think it shouldn't be that hard to port Linux and develop the effects and stuff, and to support Akai's native format? Would you give me some arguments and reasons? Thanks for the input! The datasheet you posted it nice a detailed. We would need documentation regarding the file formats, so we could implement support for them. I think the biggest problem you will come up against will be getting the equipment and the open source developers together. Unless you donate the kit to each developer, nothing will happen. The kit is far too expensive for a developer to purchase out of good will. James Is the kit totally necesary? Can we build an emulator out of the service manual? An emulator would be a natural step, i think. In any case, I have some questions about a post a friend of mine made to the forum where it all started. You can check it for yourself at: http://www.mpc-forums.com/viewtopic.php?t=54825&start=60 but I will paste it here. Can anybody comment on it? Guys, Linux as it is ordinarily distributed is not a small-footprint real-time operating system. You will notice that your cell phone does not run Linux. There is a reason for that. There is also a reason that the MPC4000 is a zero-latency device whereas a PC, even one running Linux, is not a zero-latency device; it requires audio buffering and latency compensation and all that sh*t that drives people to work on an MPC in the first place. If you haven't designed a real-time embedded application before -- e.g., the software that controls a piece of machinery or electronics -- then you are not in a good position to offer advice about how best to do this. There are public-domain RTOSes available that are suitable for this task. To those, you can add drivers for USB and FAT32. Without an RTOS to give you hard real-time scheduling, you have no chance to achieve the rock-steady timing that the MPC currently has. -illiac
You've just made a huge mistake... you just told linux zealots that linux is uncapable of something... now we are going to make it possible... ;) Anyway, you should read some stuff about linux and realtime. I agree totally that linux is not a hard-realtime OS, and was never designed to be such. So I wouldn't deploy it in a few places where QNX is king, but it's still quite capable. Here are a couple of links, it's your project, so it's totally your call: * http://linuxdevices.com/articles/AT8211887833.html this is an extract of a lkml message (available here http://lkml.org/lkml/2005/6/7/256) which compares different ways of achieving realtime in linux. * http://www.realtimelinuxfoundation.org/ it's basically a bunch of guys talking about how to make linux realtime, all the time. Check the "Variants" and "Solutions" sections. There seem to be a few hard-realtime solutions (unlike Molnar's patch, which gives you soft-realtime), but they seem quite hard to implement... haven't tried them, tho'. Now, I'm going back to lurking mode... Have fun! Regards. -Ismael C.