DOS ain't dead - AMIS, Optimize memory usage

AMIS, Optimize memory usage (Developers)

posted by Ninho , 13.05.2011, 02:07

> > > Anyway, if your goal is to optimize the memory usage of this driver:
> > ...
> > All done (credit Japheth), no fragmentation nor PSP remains in any case.
>
>
> I downloaded your program while I wrote that post and verified all of my
> points. (I also discarded one point I had in mind at first that didn't
> apply here.) Assuming you didn't silently update the program just now, they
> still all apply.

What DOS type and version please ? Under MSDOS 7, Japheth's scheme (really it's his loader I can't and won't take credit) does not create fragmentation and does remove the PSP. Zero overhead besides the 16-byte MCB. I assumed\\\hoped it would in other important DOSes too (hey! that's why I begged for beta testing out there! Thank you for actually launching the critter, in the end :=)

>> ... flags image on the stack ...
>
> Enough said.
>
> > For anybody who wouldn't believe we do not need to pass the flags along
> the
> > chain as we received "from upwards", while writing this I've been
> checking
> > a famous int 15 "hooker", MS-Smartdrv (which is willing to
> catch the "3
> > finger salute" if you wonder why it is hooking int 15). Well, MS got
> it
> > right, it doesn't lose time in needlessly preserving the flags.
>
> Yes. Right. Because if Microsoft does something some way, then it
> absolutely must be right to do it that way.

No, but maybe my example was somehow tongue in cheek, you know ?

(In case you can't tell, this
> is sarcasm. Independent of whether you should or shouldn't save the flags
> separately, I do not think reasoning with Microsoft's implementation is
> necessarily good.)

The right way (as I mentioned) is to study software int 15 (from BIOs listings, printed books, Ralf Brown's infamous list and build a few years' experience like you and me have. And brains). The MS example however is not worthless. MS systems programming (whether done in house or bought/"borrowed" I don't care) usually is excellent stuff. But there is another reason I chose that example, which is : in the terrible case that I, and MS, were wrong... it wouldn't matter that others were (in that absurd hypothesis) right : the mere existence of be it /one/ program which did not preserve the flags around its hook would make all the others' precaution useless. <G>

---
Ninho

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Complete thread:

int 15/4f French keyboard driver ready + *Ping Japheth* - Ninho, 27.04.2011, 13:34 (Developers)
- int 15/4f French keyboard driver ready + *Ping Japheth* - Japheth, 27.04.2011, 16:02
  - int 15/4f French keyboard driver ready + *Ping Japheth* - Ninho, 27.04.2011, 17:13
    - int 15/4f French keyboard driver ready + *Ping Japheth* - Japheth, 28.04.2011, 07:47
- int 15/4f French keyboard driver ready + Now what? * - Ninho, 10.05.2011, 13:30
  - int 15/4f French keyboard driver ready + Now what? * - Rugxulo, 10.05.2011, 23:52
    - int 15/4f French keyboard driver ready + Now what? * - Ninho, 11.05.2011, 13:38
      - int 15/4f French keyboard driver ready + Now what? * - ecm, 11.05.2011, 19:39
        int 15/4f French keyboard driver ready + Now what? * - Ninho, 12.05.2011, 10:56
        int 15/4f French keyboard driver ready + Now what? * - bretjohn, 12.05.2011, 17:13
        int 15/4f French keyboard driver ready + Now what? * - Ninho, 12.05.2011, 22:27
        AMIS, Optimize memory usage - ecm, 13.05.2011, 00:24
        AMIS, Optimize memory usage - Ninho, 13.05.2011, 01:33
        AMIS, Optimize memory usage - ecm, 13.05.2011, 01:45
        AMIS, Optimize memory usage - Ninho, 13.05.2011, 02:07
        AMIS, Optimize memory usage - ecm, 13.05.2011, 02:39
        AMIS, Optimize memory usage - Ninho, 13.05.2011, 02:58
        Correction, memory usage - Ninho, 13.05.2011, 02:50
        Memory usage, AMIS(!) - ecm, 13.05.2011, 03:00
        Memory usage, AMIS(!) - Ninho, 13.05.2011, 11:57
        Memory usage, AMIS(!) - ecm, 13.05.2011, 14:51
        Memory usage, AMIS(!) - bretjohn, 13.05.2011, 17:43
        Memory usage, AMIS(!) - Ninho, 13.05.2011, 18:15
        Memory usage, AMIS(!) - Japheth, 13.05.2011, 18:58
        Memory usage, AMIS(!) - bretjohn, 14.05.2011, 01:42
        Memory usage, AMIS(!) - Ninho, 14.05.2011, 11:38
        Sorry error :) - No contents - Ignore - Ninho, 14.05.2011, 11:41
        Memory usage, AMIS(!) - bretjohn, 15.05.2011, 17:26
        Int15 handler example: IISP; chain other functions directly - ecm, 15.05.2011, 18:30
        Int15 handler example: IISP; chain other functions directly - Ninho, 16.05.2011, 03:49
        Memory usage, AMIS(!) - Ninho, 15.05.2011, 20:57
        In reply to Bret - int 15/4F stuff - Ninho, 16.05.2011, 03:35
        In reply to Bret - int 15/4F stuff - Japheth, 16.05.2011, 10:18
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - Ninho, 16.05.2011, 12:19
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - tom, 16.05.2011, 13:35
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - Ninho, 16.05.2011, 15:10
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - tom, 16.05.2011, 17:13
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - bretjohn, 16.05.2011, 19:50
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - tom, 16.05.2011, 21:06
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - bretjohn, 17.05.2011, 18:10
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - tom, 17.05.2011, 19:47
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - bretjohn, 18.05.2011, 02:09
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - Japheth, 18.05.2011, 06:47
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - bretjohn, 18.05.2011, 19:08
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - tom, 18.05.2011, 12:35
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - bretjohn, 18.05.2011, 18:14
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - tom, 19.05.2011, 15:32
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - Rugxulo, 19.05.2011, 22:42
        Keyboard, codepages... - Ninho, 19.05.2011, 23:41
        FreeDOS DISPLAY (TSR vs. device driver?) - ecm, 20.05.2011, 14:09
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - Ninho, 19.05.2011, 23:59
        In reply to : Bret 'll have to hate FreeDOS mKEYB, too - tom, 20.05.2011, 00:49
        In reply to Bret... - Ninho, 18.05.2011, 15:41
        DOS IO kernel part hooking Int15.4F ? - ecm, 18.05.2011, 20:35
        DOS IO kernel part hooking Int15.4F ? - Ninho, 18.05.2011, 22:41
        DOS kernel, Int15.4F - ecm, 18.05.2011, 22:48
        In reply to Bret... - tom, 19.05.2011, 15:15
        In reply to \\\ Tom... - Ninho, 19.05.2011, 19:27
        AMIS, Optimize memory usage - Japheth, 13.05.2011, 07:28
        AMIS, Optimize memory usage - Ninho, 13.05.2011, 11:27
        AMIS, No flaming - ecm, 13.05.2011, 00:24
        AMIS - ecm, 13.05.2011, 00:24
        AMIS - Ninho, 13.05.2011, 02:21
        AMIS, Ciriaco - ecm, 13.05.2011, 03:23
        AMIS, Ciriaco, Ralph ? - Ninho, 13.05.2011, 12:16
      - int 15/4f French keyboard driver ready + Now what? * - Rugxulo, 11.05.2011, 20:12
        int 15/4f French keyboard driver ready + Now what? * - Ninho, 12.05.2011, 10:36