> The last time I heard of a 12 MHz bus in a PC system was in the days of > the PC-AT, when some clone makers sped up their buses (pre PCI!!!) in an > attempt to allow adapter card *memory* to run at the 12 MHz speed.
It wasn't about clone makers speeding up their busses. The ISA bus originally ran at the CPU clock - 4.77/8/6/10 .. etc. Quite a few board makers assumed 8MHz and while faster isn't a big problem at 8bit trying to do the 8/16 bit decode with logic chips at 8MHz is quite tight and above that generally broke. 8bit tends to work fine because you've got a lot more timing headroom. > I can't believe that we are not supporting today's machines correctly > because we are still trying to be compatible with a few (at most a > hundre thousand were manufactured! Much less still functioning or > running Linux) machines. It is about supporting this properly. Properly for ISA devices means using I/O delays. Properly for chipset devices is probably using udelay. > Now I understand that PC/104 machines and other things are very non PC > compatible, but are x86 processor architectures. Do they even run x86 > under 2.6.24? Linux runs on x86, it isn't limited to PC type architectures at all. We don't need a BIOS, we don't need legacy compatible I/O devices. > for "relics" and develop a merged architecture called "modern machines" > to include only those PCs that have been made to work since, say, the > release of (cough) WIndows 2000? No point. We've got the 64bit kernel for that. That is a much saner boundary to throw out all the nutty stuff. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
