| ??? 05/10/08 02:30 Read: times |
#154632 - The point of Windows, yes, but not what I want Responding to: ???'s previous message |
Neil said:
If you want to play with the hardware you need to be a driver. Otherwise any user program can hang or crash the system. Like back in the Windows 3.1 days. There are drivers around to let you play with the printer port. But you can not hold the system to control the timing. serial or parallel. Preemptive multitasking. You can do things in increments of system clock ticks. But, the timing may not be very solid.
DOS may still run on a newer system. Unless it is too fast. but I guess you could clock it down. Otherwise write a program for a micro to do it. I guess my point is that underneath it all, a PC is just another micro. I would like to be able to treat it as such sometimes, knowing full well that I am trading all the protection features for fine control of the hardware. Certainly, if a guy wanted to, he could write a program that would completely replace the BIOS, figure out how to load it onto the flash/ROM/whatever on the motherboard, and be running his own code that could do whatever it wanted starting with the very first instruction at the boot location. Perhaps the next easier step would be to make a bootable disk (a CD these days, I guess) containing a program that would take off and run at the point where the BIOS normally tries to boot an OS. It seems that would let the BIOS handle (at least some of) the peculiarities of the particular hardware it's running on. It would also eliminate the inconvenience of having to re-flash or re-ROM or re-whatever the user program every time it changed (as you have to do normally with a microcontroller). That actually sounds like an interesting project: Create a floppy or a CD that boots directly into a program that prints "Hello, fatso!" on the screen and then just hangs the computer. How hard could that be? Then the next easier step from there might simply be to use some old version of DOS that doesn't even think about putting the CPU into protected mode. Of course it wouldn't have half the drivers you'd need to run a modern PC with all of its peripherals, but neither would you have those with the previous, lower-level ideas either. For the record, I did find an old DOS diskette a little while ago and it did boot and run on my current semi-modern Pentium 4 machine. That was encouraging. -- Russ |
