Description and characteristics of DOS Sessions in MS-Windows 95, 98, and XP.
How to start and customize the DOS Session.
MS-DOS Sessions in Windows
Starting DOS Sessions in MS-Windows
Starting an MS-DOS session from within the MS-Windows 95,98,XP GUI
causes VMM (virtual machine manager) to create virtual machine for
the session with 1mb of memory (640kb conventional and 384kb of upper
memory). VMM also creates a DOS environment based on defaults in IO.SYS
and any other settings in AUTOEXEC.BAT and CONFIG.SYS.
DOS sessions have access to long file names, multitasking, 32-bit disk caching, protected mode drivers for the mouse and CD-ROM, etc. etc.
Starting DOS Sessions (type EXIT to return to GUI)
Method
Notes
Run Command
Can use parameters and switches for COMMAND.COM (see Unleashed; p.660)
Starts DOS in drive/directory currently selected in Windows Explorer
(or C:\WINDOWS\DESKTOP if Explorer not open)
Start Menu, Programs, MS-DOS Prompt
This shortcut is not always present
Double-click COMMAND.COM
Double-click on C:\COMMAND.COM or C:\CMD\COMMAND.COM from
Windows Explorer
Create shortcut to DOS on desktop or Start menu
Can use parameters and switches for COMMAND.COM (see Unleashed; p.660)
Open folder in DOS Window from Windows Explorer context sensitive menu
First create a new action for
Explorer's context-sensitive menu
Customizing DOS Session Settings
There are many settings for DOS Sessions. These settings are made using the properties sheet either for a program or a shortcut.
When you set the properties for either a DOS program or a shortcut to a DOS program you are actually creating a PIF for that program.
Unless you want to start the program by double-clicking on its icon in Windows Explorer there is little point in setting the properties for the program file itself.
It is much more convenient to start programs either directly from the Start menu or the desktop or from a folder in the Start menu or the desktop. To do so we do not place programs themselves on the desktop or the Start menu, we put a Shortcut to the program in one of those places. Therefore it is more common to set up the properties for a program's shortcut then for the program itself.
The properties sheet for a shortcut is accessed by right-clicking on the shortcut and then choosing Properties. The properties sheet has five tabs, each with its own settings:
Program Tab
Setting
Explanation
Command Line
Path and name for the program, as well as any parameters or switches.
Working
What the current drive and path should be when the program is started.
DOS programs sometimes need to find their data in the current directory, or
this may just be for the user's convenience when retrieving files.
Batch file
Specify a batch file to run before the program is started. A batch file may
be used to set environmental variables, copy files, change the path, load tsr, etc.
Shortcut key
Ctrl-Alt-key keyboard shortcut to launch the program.
Run
Normal, Minimized, or Maximized window (also see Screen)
Advanced
This is where you can specify MS-DOS Mode for a program. When MS-DOS Mode
is specified none of the other settings are used because Windows will boot
to Real Mode. See Customizing MS-DOS Mode below.
Change icon
Specify a path and filename for the icon to represent the shortcut.
Close on Exit
Check this box to have windows close the window when the DOS program
terminates.
Font Tab
Setting
Explanation
Font size
Choose a font size for the program to use when it runs in a window.
Memory Tab
Setting
Explanation
Conventional Memory
Total. VMM gives every DOS session 640k of memory by default.
Many don't need that much, so specify less to conserve
system resources (or reduce paging to the swap file, as is
the case).
Initial environment. Increase the size of the DOS environment
for the DOS session.
Protected. Check off to write protect system memory area and
prevent the DOS app from crashing Windows.
Expanded (EMS) memory
Total. Set to none if you know the program doesn't use expanded memory,
or limit it to a specific amount rather than let VMM give the app as much
as it likes. Note: if not available it probably means that NOEMs is in the
CONFIG.SYS.
Extended (XMS) memory
Total. Ditto Expanded memory.
Uses HMA. Should program have access to HMA? Probably not, but perhaps to load device driver.
MS-DOS protected mode (DPMI) memory
Amount of protected mode memory available to the app.
Screen Tab
Setting
Explanation
Usage
Run program full-screen or in a window.
Number of lines on screen (both full-screen and window).
Window
Display toolbar by default.
Restore settings on startup. Restores the window size and position from the last session if checked.
Performance
Fast ROM Emulation. When checked allows Windows to emulate ROM BIOS video services with RAM-based virtual VxD's (virtual device drivers), which are faster. Disable is compatibility issues due to program making non-standard ROM calls.
Dynamic memory allocation. When checked allows VMM to reduce (and therefore conserve) allocated memory when a DOS program switches from Graphics mode to text mode. Unchecking it forces VMM to always give enough for graphics mode.
Misc Tab
Setting
Explanation
Allow screen saver when program is in foreground?
No for communications programs or if screen saver causes a conflict
with program. (DOS box becomes minimized when screen saver kicks in)
Mouse
QuickEdit. Enables selection of text with mouse when program running in a window.
Exclusive Mode. Use only if mouse won't otherwise work in DOS program.
Background
Always suspend in background? Uncheck if program does no background
processing to stop it from stealing cpu cycles from other running apps.
Termination
Warn if still active. Warn you if you try to close the window without
first shutting down the program (can cause loss of data).
Idle Sensitivity
How much cpu time program gets when it is idle. The lower the Idle
sensitivity the longer Windows waits before declaring the program
idle and reducing its cpu cycles. This will increase efficiency of
DOS programs which do process in background but, unlike Windows programs,
have no way of communicating their current state.
Fast pasting
How fast information is pasted from clipboard into the program. Many DOS programs
can't handle full speed and text gets scrambled.
Windows Shortcut Keys
Deactivates the windows shortcut keys if they are used by the program.