I am trying to hunt down what I believe is an IRQ problem associated with my serial driver. I guess I am using old style interrupts. In 2.4.0-test 5 the file arch/mips/kernel/irq.c used to be built. Under 2.4.3 it no longer is. However, it appears it was renamed to old_irg.c and a new irq.c was created. I also noticed that an i8259.c files was added at some point. However, it does not seem to match the code that was in irq.c. Are there any notes available that explain how to convert from old style IRQ's to new? What are we suppose to do with the new irq.c which is not being used? I have a 2.4.3 kernel booting. I copied the old arch/mips/kernel/irq.c to my target directory and changed a few other things to get everything to compile. As long as I do not try to use a serial port everything seems to be working. I booted with a frame buffer and started X. The mouse and keyboard worked so some of my IRQ's appear to be working. When I start the serial port things seem to go fine untile it trys to write the port at which point it starts running very slowly. Which is what make me think the kernel is being overcome with interrupts. Thanks for any thoughts or advice. Scott