🚀 go-pugleaf

Okey First I just want to say I have NOTHING against WIN95 except the frustration of
the postpone to the official release date to the REAL THING. I'm curious about the
program, wants to learn how it wil (or will not) affect my computing. Anything I'm
going to say is NOT intended as a flame and should NOT be used to say against WIN95,
Rather, I am trying to learn how exactly the program handles things and it's
advantages and disadvantages when handled that way. Ultimately, I want to see if
win95 suits *ME* or should I stick with other OSs. (i.e. Linux, OS/2, DOS,etc)
I currently own MSDOS, WFW 3.11 and OS/2 warp. I have also used Unix, Win NT and
Macintosh OS. I'll begin first by stating that I very much like the stability and
crash proof of Unix OSs, I very look forward to MULTITASKING environments, and I
have been computing long enough in the PC world to be very knowledgable in many
aspects. Do understand that because that only true 32-bit preemptive multitasking OS
in the PC I've used is the OS/2, I might be using examples of OS/2 here and then.
They are not ment to glorify OS/, bash win95,etc. Just to verify that WIN95 can
indeed do certain things I look forward to.

Now that the disclaimer is out of my way, lets get on with my questions

In article <saswta.7...@sas.com>, Bill Arnette <sas...@unx.sas.com> wrote:
>sas...@unx.sas.com (Bill Arnette) writes:
>
>> [ snip ]
>>>From the Windows 95 Resource Kit on the build 445 CD-ROM:
>
>>Application Support/
>> Technical notes on application support/
>>  Support for MS-DOS Based applications:
>
>>   "As with Windows 3.1, each MS-DOS - base application runs in its own
>>   DOS virtual machine (VM), which allows multiple 8086-compatible sessions
>>   to run on the CPU, which in turn allows existing MS-DOS - based
>>   applications to run preemptively with the rest of the system."
>

First, Does this means that Win95 can MULTITASK DOS VDM? Because I'm foremost looking
for a *TRUE PRE-EMPTIVE MULTITASKING OS* and I really would like to multitask in
DOS. The easiest way to test this I think, will be to load up DOS VDM under win95,
play a MOD file (i.e. I think DMP or most popular modplayers should do) and then
switch back to win95's equivalent of program manager. Is the music still there?
(this test should also be able to test the stability of win95, because mod playing,
especially using a SoundBlaster XX crunches up tons of resources and generates tons
of system interrupts and DMAs). Does the music die down if I start another DOS VDM?
(try playing the DOS QBASIC's NIBBLES or any other games that do not use soundcards)
Also, can someone tell me how well windows handles DOS communication softwares? I
know win95 native comm program would exist, but I just like to test the stability
and comm port handling ability of win95 DOS VDM. What happens when you try to use
the same comm port? (i.e. load up another comm program that uses the same comm port)

Secondly, I assume that even if Win95 cannot multitask DOS VDMs, can win95 native
applications themselves be able to multitask? (i.e. if someone writes a modplayer
from scratch, using whatever tools win95 supports, will a multitaskable modplayer be
available?) Also, if true, does the multitasking process gets frozen when a DOS VDM
starts?

Well, the first two is for quering the multitasking ability of win95 DOS VDMs. Next
I'll like to ask certain things about system protection and stability:
(any programmer should be able to do this easily)
What happens when:
1. a program executes an endless loop: (i.e. a while(TRUE) loop)
   - Does win95 slow down (i.e. system resource gets gobbled up)?
2. a program polls the keyboard continuously: (i.e. a while(!kbhit()) loop)
   - Does win95 slow down?
   - Is the VDM smart enough to detect the polling and reduce allocated CPU timeslices?
     - If KB polling cannot be detected, is the simple scanf command detected and
       timeslice reduced?
3. a program access an illegal memory space. (i.e. illegal pointer)
   - does win95 protect the whole system from crashing?
   - is the write memory command actually carried out (hence violating system
     integrity)?
4. a program tries to write to the system area in the harddisk. Does win95 allow
     that? I ask this because as far as I know, a program in the DOS VDM in OS/2 cannot
     write to certain system area, some sort of system integrity protection measure.
     The good side-effect is that trojans/viruses cannot delet/format the harddisk!
5. 2 programs tries to open the same file for read and write. (i.e. wordstar for DOS
     and microsoft word has "client.lst" open) What happens when either tries to
     save the file? Suppose a disk-based sorting program ran twice, what happens  
     when they try to sort the same file? Or WCIII ran twice, (if you have the memory),
     will the two WC crash each other? or will the other one simply not allowed to
     start. Also, what if the file was deleted after a client opens it?
6. a program uses "special" modes of SVGA cards? will win95 able to restore the
     "non-standard" video mode after switching?
7. two programs requests for same soundcard? two program requests for same hardware
     interrupts?
8. What if one of the DOS VDMs tries to execute codes that will cause the system to
     reboot? Will win95 trap and stop that? or does the system reboots?
9. If somehow a DOS VDM has crashed (but win95 still alive) is the memory allocated by
     the doomed VDM recovered? Does win95 do anything about the resulting memory
     fragmentation?
10. what happens if a win311 program crash? will win95 crash or stay well? Do
     screensavers from win311 still work in win95? (some didn't work in OS-WIN)
11. Finally, I'm *REALLY* curious as to whether you can start a win3.11 session under a
     DOS VDM. (i.e. whether u can start win311 under win95) Or if win311 fails, can you
     run Desqview (or Desqview/X) under win95? I know this sounds really crazy, but
     I just want to know how extensive is the win95 DOS VDM.

>However, here is an exceprt from the mem /c output in several differently 
>configured DOS sessions running at the same time on a IBM PS/2 Model 90 
>w/32M RAM :
>
>  Session with Auto EMS:
>
>    Total Expanded (EMS)                  32,964,608  (31M)
>    Free Expanded (EMS)                   16,777,216  (16M)
>    Largest executable program size          614,000 (600K)
>    Largest free upper memory block                0   (0K)
>    MS-DOS is resident in the high memory area.
>
>  Session with no EMS
>
>    Largest executable program size          614,000 (600K)
>    Largest free upper memory block                0   (0K)
>    MS-DOS is resident in the high memory area.
>       
>  Session with Auto EMS and 280K Conventional
>
>    Total Expanded (EMS)                  32,964,608  (31M)
>    Free Expanded (EMS)                   16,777,216  (16M)
>    Largest executable program size          280,176 (274K)
>    Largest free upper memory block            2,112   (2K)
>    MS-DOS is resident in the high memory area.
>

Erm I noticed that there's no mention of DMPI memory. Does win95 provide DPMI
access? Also, inside a VDM, how much UMB memory MAX is available for DOS programs?
Will win95 allow the loading of a mouse driver inside a VDM (I know it's
unnecessary, but will loading a real mouse driver screw up the mouse driver of win95?)

>It is true that you cannot specify FILE= and BUFFERS= or any other
>options that you would specify in a CONFIG.SYS file.  But you can specify a
>.BAT file to be run before your application much as an AUTOEXEC.BAT file
>might be run.

If not, what is the default FILE=? Do win95 use up any of the defined value? (i.e.
if declare FILE=20, when under DOS VDM, win95 uses up 15, that's not good.)

How does win95 handle ASPI SCSI drivers and drives? Does it use SCSI drives wisely
(like they're designed to when multitasking) or just use it as an IDE drive? Can a
SCSI tape backup program using ASPI be run in the background in a DOS VDM? (This
is one of the most useful aspects of OS/2)

Do device drivers (like scanner device drivers, Magnetic Optical drive drivers,
Removable catridge drive drivers) from DOS get to be loaded? Or do I have to try and
get drivers that are specially made for win95 for these devices?

How well does win95 do a background floppy format? In win311, if you format a disk
in background, your mouse pointer "teleports" when you try to move them, and many
times I get bad sectors when the disk is actually okey. How well does win95 handles
this? What if I chose to format the disk under the old filemanager of win311 or DOS
VDM format? Any effects?

What options are allowed for a DOS VDM session? OS/2 allows extensive modifications
to allow much optimizations for individual DOS VDM session/program. How extensive is
win95's?

One plus point in OS/2 is that for those games that can be run from a window, it is
said that you can actually do graphical cut-and-paste from the DOS windowed VDM onto
the clipboard or practically anywhere else. This is great for "notekeeping" in rpgs,
and mapping for 3-D games. Does win95 offer something similar to this?

One more thing, I heard win95 offers long filenames (FINALLY! get away from that
stupid 8.3 format) but is it really filenames or just mapping of 8.3 files onto long
descriptions? I've heard contradictory info on this and would like to confirm the
real way win95 is doing this. How does "This is a very long file - 1" and " This is
a very long file - 2" and "This.is.a.very.long.foldername" gets stored on the disk?
Is there's any way to do a search for all occurance of "a very long" and rename to "a
very short" on the whole harddisk? If win95 does by mapping, how does the real 8.3
source filename gets changed? Does win95 support NTFS or HPFS?

That's about all I can think of at the moment. If anyone wants to add to this list,
feel free to ask.

Thank you for reading this far and please do answer these if you know the answer.
Please do not flame, as you can see I'm really trying to find out how well win95
handles verious demanding situations. For the good of others who might be needing
these informations too, please try to post it. Also, please try to make the answer
as impartial and detailed as possible. For tests on stability, just launching a
program is not good enough, if it's a game, try the intro, load/save game and maybe
playing a while, all the while trying the switch between game and win95 at all
stages. If it's an application, try do very complex things and try opening multiple
files (i.e. >20 documents) if it's something like spreadsheet, wordprocessors,etc.
For mathematical/graphing/CAD/rendering programs, please try to make complex
graphs/pictures/formulas/etc and all the time try the switch between a DOS VDM and
the program. This will really confirm the stability of the system.

See ye!

Hon Chong Chang
Drexel University
Computer Science Major.