Difference between revisions of "Talk:83Plus:OS:Memory Layout"
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Hey, I just saw that Usermem is listed before temp mem, even though it comes after it. What's up?? [[User:Luby|Luby]] 13:28, 17 April 2008 (PDT) | Hey, I just saw that Usermem is listed before temp mem, even though it comes after it. What's up?? [[User:Luby|Luby]] 13:28, 17 April 2008 (PDT) | ||
| + | :Um... what? Yes, temporary memory comes in between user variables and the FPS. This is so that temporary variables can be allocated and deallocated more quickly. When you InsertMem or DelMem within that area, the OS doesn't need to move around (potentially very large) user variables and programs. In addition, it only needs to look at the temporary VAT -- since user variables aren't being moved, the normal symbol/program VAT can be ignored for these operations. [[User:FloppusMaximus|FloppusMaximus]] 21:26, 18 April 2008 (PDT) | ||
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| + | :Usermem starts at 9D95 but temp mem is at 9820 and yet we have in the second line Usermem to (tempmem)-1. That doesn't make sense, no?? [[User:Luby|Luby]] 07:04, 21 April 2008 (PDT) | ||
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| + | ::No, tempMem is a ''pointer'' to the beginning of temporary memory. That pointer is located at 9820h. The actual temporary memory is dynamically allocated. Note the parentheses. [[User:FloppusMaximus|FloppusMaximus]] 13:49, 21 April 2008 (PDT) | ||
Latest revision as of 12:49, 21 April 2008
Hey, I just saw that Usermem is listed before temp mem, even though it comes after it. What's up?? Luby 13:28, 17 April 2008 (PDT)
- Um... what? Yes, temporary memory comes in between user variables and the FPS. This is so that temporary variables can be allocated and deallocated more quickly. When you InsertMem or DelMem within that area, the OS doesn't need to move around (potentially very large) user variables and programs. In addition, it only needs to look at the temporary VAT -- since user variables aren't being moved, the normal symbol/program VAT can be ignored for these operations. FloppusMaximus 21:26, 18 April 2008 (PDT)
- Usermem starts at 9D95 but temp mem is at 9820 and yet we have in the second line Usermem to (tempmem)-1. That doesn't make sense, no?? Luby 07:04, 21 April 2008 (PDT)
- No, tempMem is a pointer to the beginning of temporary memory. That pointer is located at 9820h. The actual temporary memory is dynamically allocated. Note the parentheses. FloppusMaximus 13:49, 21 April 2008 (PDT)
