Chaining TSRs ?
Chaining TSRs ?
The concept refers to linking TSRs that trigger reminders as described in the Wikipedia article.
The usual way to handle an interrupt vector is to read its current value (address), save it in the TSR's memory area, and then use that saved address within the code. The saved address is retrieved from the TSR, creating a sequence of interrupt handlers, also known as interrupt service routines or ISRs. Installing these handlers is referred to as chaining or hooking an interrupt.
The usual way to use an interrupt vector includes reading its current value (the address), saving it in the memory area of the TSR, and swapping it with a different address in its own code. The saved address is retrieved from the TSR, creating a single linked list of interrupt handlers, also known as interrupt service routines or ISRs. This method of setting up ISRs is referred to as chaining or hooking an interrupt or an interrupt vector.
"meaning of addresses": the memory addresses.
"reading its present value": looking at the contents/what is stored there in any given memory address.
FYI - based on my understanding of your questions:
https://www.w3schools.com/c/c_memory_add...~:text=The memory address is the,stored in this memory address
.
https://courses.cs.washington.edu/course...r6_Storing Data Using Memory.html
= = = =
That said, I am going to make a suggestion that will prove helpful to you and to those who respond to your questions.
Helping to address and answer questions is the basic purpose of this Forum.
However, I recommend that, in addition to your question, that you also provide what you believe to be the answer and include some source or reference for what you believe to be the answer.
For the most part, four things will happen:
1) You are likely to find or otherwise work out the answer(s)on your own. Definitely an advantage with respect to developing more IT skills.
2) Also likely that you will save time by finding answers (or potential answers) on your own. No reliance on others being available to respond much less delays due to time zones, internet communication problems, etc..
3) Presenting your own answers and supporting those answers to others is another important skill to develop.
4) And if there is some problem regarding your answer (and that does not always mean that the answer is wrong) then the Forum can help clarify the answer and perhaps even the original question itself.
When you ask a question simply state what you think or believe is is the answer. And, if necessary, why you think that is the answer.
I can express what I believe.
There seems to be a table of addresses that explain how to operate a hardware component. For example, in Address 1000H there is a routine that provides the instructions for the keyboard hardware. I could adapt this in my own code, which is what TSR stands for.
In the values they mention about hardware vectors (???) I can modify the computer's operating system to perform different actions with my TSR.
Understood. What do you think about this? Is it accurate?
Code/instructions are kept in memory. Ideally, they should be stored in a continuous, address-based sequence. But if this isn't feasible, there might be some code at the final memory location that points to another address where the next instructions start.
You can inspect memory and its contents using various tools and applications; debuggers are among them.
If you understand or can identify the memory range for a TSR program (such as a keyboard driver), then with the right permissions and tools, you can access individual memory addresses to modify their contents.
However, you need to be certain about what changes to make, where to change it, and why. Any mistakes will lead to error messages or program crashes.