Date:	Tue, 29 Sep 1998 15:58:13 +0100
From:	Matthias Paul <PAUL-MA AT reze-1 DOT rz DOT rwth-aachen DOT de>
Subject:	Re: Suggestions for DR-DOS
To:	opendos AT delorie DOT com
Reply-to:	Matthias DOT Paul AT post DOT rwth-aachen DOT de
Message-id:	<1700173701D@reze-1.rz.rwth-aachen.de>
Organization:	Rechenzentrum RWTH Aachen

Hi,

In the attempt to report only correct information, I'd like to 
add a few extra comments regarding my 1998-09-25 reply to Guti's 
posting:

[FASTOPEN]

>Please mind that Caldera s implementation is using a very efficient 
>hash table mechanism. A single reference takes only 2 bytes for 
>DR-DOS. So settings like FASTOPEN=512 or FASTOPEN=1024 that would 
>consum several Kilobytes of memory on MS-DOS/PC DOS systems just 
>use up a few bytes on DR-DOS...

In other words: Under DR-DOS a setting of FASTOPEN=512 consumes 
0.5 Kb for up to 256 files, while for the same number of files 
MS-DOS' FASTOPEN=256 would use up 12 Kb (48 bytes per file).

[DOSKEY]

>If you specify HISTORY=OFF, IBMBIO.COM will even dynamically 
>discard the code needed for this.

I have to correct myself: While it is IBMBIO.COM that discards this
code, of course the history code is actually part of IBMDOS.COM. 

It comsumes about 1 Kb without the history buffers, so HISTORY=512 
would reduce available memory by 1.5 Kb. Adding 1.5 Kb for the DOSKEY 
code including a 512 byte macro buffer, the whole thing would use up 
3 Kb with 512 bytes for the history buffers and a *separate* 512 byte 
macro buffer. Contrast this with MS-DOS 6.22 DOSKEY with a 1 Kb 
buffer taking up approx. 4.5 Kb (newer issues may use up more 
memory). 

BTW. DOSKEY was introduced with MS-DOS 5.0, not MS-DOS 6.0.

[KEYB]

Regarding KEYB flushing dirty buffers on pressing CTRL+ALT+DEL:

While my previous description is valid for (current issues of) MS-DOS 
KEYB and Axel's and mine FreeKEYB/K3PLUS, DR-DOS KEYB works a little 
bit different due to the fact that it partially uses the original 
keyboard driver in the ROS to save memory. In current issues of DR-
DOS KEYB, CTRL+ALT+DEL is passed down to the ROS, which then usually 
boots the machine. However, KEYB itself does *not* force the buffers 
to be written out to disk, so for reasons of safety Guti's suggestion 
is really something to be thought off (though I'm not sure if it 
would be possible to add within the current architecture of KEYB).

DR-DOS EMM386 intercepts reboots by setting a trap at the ROM BIOS 
entry point.

NWCACHE hooks INT 09h to get acknowledged when the system is about
to be rebooted. It is NWCACHE, not DR-DOS KEYB, which shuts down a
PNW server and waits until all dirty buffers have been written out
to disk.

I'm not sure about 3rd party caches like SMARTDRV, since under MS-DOS
the keyboard driver internally handles CTRL+ALT+DEL and instructs the 
cache to flush buffers. 

In general, 3rd party software which needs to be informed of a 
pending reboot should hook INT 15h/4Fh (on ATs) or INT 09h (on older 
machines).

[Eurocurrency in DR-DOS]

While some members of Caldera's staff might monitor this list, 
I'd like to suggest to not forget to report directly to Caldera at 
<dos DOT support AT caldera DOT com> (or <dosbeta AT calderauk DOT com> for beta 
software) what kind of features you need / want in DR-DOS... 
This will ensure that your suggestions will be logged in the data 
base and might be taken under consideration for future products.

 Matthias
 
-------------------------------------------------------------------
Matthias Paul, Ubierstrasse 28, D-50321 Bruehl, Germany
eMail: <Matthias DOT Paul AT post DOT rwth-aachen DOT de>
Web  : http://www.rhrz.uni-bonn.de/~uzs180/mpdokeng.html
------------------------------------------------------------------- 
Caldera Digital Research Systems/OpenLinux: http://www.caldera.com/
-------------------------------------------------------------------

- Raw text -