Re: Simulating slower processor.

From: Paul Barton-Davis (pbd@Op.Net)
Date: Tue May 02 2000 - 21:28:23 EST

>From: "Richard B. Johnson" <>

>Make a driver on IRQ7 (the printer port). It contains just an ISR.
>The ISR just wastes some time (you can make it variable with an
>ioctl()), then returns.
>Connect a function generator to your printer port, + 5V, 50 to 50 kHz.
>The faster you interrupt, the slower your PC.

This can be done much more easily with the RTC driver. Just start up a
program that programs it to do periodic interrupts at 4096Hz, and
you'll see a nice overall slowdown in your machine. Add a while loop
to the interrupt handler in linux/drivers/char/rtc.c if you want more
of an effect. Don't go above 4096Hz, because the RTC will stop
generating interrupts as soon as one is not ack'ed in time, and that
tends to happen with 8kHz.


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