China DOS Union

Is the real-time performance of DOS good?

Without an interrupt scheduling mechanism and without context switching, can it be more real-time, you say?

Not having an interrupt scheduling mechanism is not necessarily a good thing. When multiple programs hook the same interrupt, or you can't finish the required work in a single clock interrupt cycle, then trouble will arise.

So, the book emphasizes for interrupt programming:
You should set STI as soon as possible, and output to 20h, AL as soon as possible. This is to avoid blocking other programs.
You should set reentrancy flags and plan the stack. This is to ensure the reentrancy safety of your own program.

Originally posted by netwinxp at 2007-7-27 01:48:
Not having an interrupt scheduling mechanism is not necessarily a good thing. When multiple programs hook the same interrupt, or you can't finish the required work in a timely manner within a clock interrupt cycle, then troubles will arise.

I understand what the LZ means, but I just know that DOS is single-tasking, not easy to crash, and relatively more stable than WINDOWS.

In embedded applications, where high precision is required, DOS is better than Windows. This is for scenarios where the system can often change positions and be used by non-professional personnel!

In system integration, where precision requirements are not high, Windows is better than DOS. This is for scenarios where the system is generally fixed in position and used and maintained by professional technicians!

[ Last edited by windowsvesta on 2007-9-12 at 10:44 AM ]

Windows, besides having weak real-time performance, is that the operating system needs to be reinstalled after the device has been used for a while! When a非正常shutdown occurs, Windows needs to scan the disk, and the boot time will make you wait a long time. If the disk is not scanned for a long time, the system will soon crash!

No matter which system, if the program is good, the real-time performance is good!

When using timing interrupts under DOS, and if a Chinese system (even a direct screen-writing Chinese system that also uses timing interrupts) is used, it is very easy to have interrupt reentrancy, leading to a system crash. If you use the method of receiving messages and then post-processing in Windows, instead of intercepting messages, it also has good real-time performance (remember to disable unnecessary service processes as much as possible). Windows has a very large advantage in interface processing, driver program processing, I/O port processing, etc. The real-time processing part of Windows needs to be written using.SYS.