DOS ain't dead

Swap! (Developers)

posted by ecm  , Düsseldorf, Germany, 25.05.2011, 14:13
(edited by cm on 25.05.2011, 14:25)

> > I don't think that would really be of any use. It might prevent
> > interference by some TSRs which check for InDOS before issuing
> > 21.48/.49/.4A but it's not a good solution. (In fact, I think protecting
> > critical sections by the InDOS flag is generally not a good idea and
> > should only be done if really necessary.)
>
> ...

I wasn't referring to the hypothetical TSR associating resources with other processes here, I was referring to very real TSRs which might pop up pretty much any time interrupts are enabled and which could interfere with your memory reallocation if you relied on every TSR to check for InDOS before it modifies MCBs one way (Int21) or another (direct access).

> Now the price being cases where it won't be able to run for lack of memory.
> Of course that is more theoretical than practical for our little keyboard
> helper!

If your program takes up that much memory swap it to a file

Seriously though, the only case in which the complete process relocation would fail was if there wasn't enough space available to relocate the complete process. If you trim the process to be relocated as much as possible first, you'll only have to allocate 80 bytes for the reduced PSP and enough space for the remaining installer code (including the image to install later on) plus some stack space. Assuming a 512 byte image (I think your installed TSR currently is about that large) the relocated installer process can take up less than 1024 bytes.

> meanwhile potential users can rely on the last version advertised in the
> Announcements section.

Yes, I'd agree that this version is the best for end users right now.

---
l

Complete thread:

• keyb: new! memory scheme, easy TEST - Ninho, 22.05.2011, 19:10 (Developers)
  • boring - ecm, 22.05.2011, 23:58
    • boring - Ninho, 23.05.2011, 01:20
      • not that boring after all (nt) - ecm, 23.05.2011, 13:27
  • review - ecm, 23.05.2011, 13:18
    • review - Ninho, 23.05.2011, 23:10
      • review - ecm, 24.05.2011, 00:45
        • review - Ninho, 24.05.2011, 12:50
          • review - ecm, 24.05.2011, 15:20
            • of TSR powers & limits - Ninho, 25.05.2011, 11:24
              • Swap! - ecm, 25.05.2011, 14:13
                • of TSR powers & limits - Ninho, 25.05.2011, 15:14
    • fix - Ninho, 29.05.2011, 14:36
      • opinion - ecm, 29.05.2011, 14:49
        • opinion - Ninho, 29.05.2011, 16:36
          • evaluation - ecm, 29.05.2011, 17:26
            • evaluation - Ninho, 29.05.2011, 21:00
              • hardly a 100% solution - ecm, 29.05.2011, 22:17
                • hardly a 100% solution - Ninho, 30.05.2011, 19:26
                  • hardly a 100% solution - ecm, 30.05.2011, 19:33
                    • hardly a 100% solution - Ninho, 30.05.2011, 21:14
                      • hardly a 100% solution - ecm, 30.05.2011, 21:20
                        • hardly a 100% solution - Ninho, 30.05.2011, 23:50
                          • allocation no higher than the PSP - ecm, 30.05.2011, 23:56
                            • allocation no higher than the PSP - Ninho, 01.06.2011, 18:56
                              • allocation no higher than the PSP - ecm, 01.06.2011, 19:10
          • opinion - Ninho, 30.05.2011, 19:04
            • sti - ecm, 30.05.2011, 19:26