Contents of the CAMERA7.DOC file
PRESENT CAMERA Version 7.0
c.1987,1988 SML Services, Inc.
CAMERA is a memory-resident screen capture program designed for use with
the PRESENT Slide Presentation System.
To use the camera, you must first install it. Once installed it will
remain resident in memory. The Program is invoked by pressing the
"Shutter" hot key combination, Alt-Tab, which will take the currently
active video screen buffer and save it in a file. The contents of the
mode and color registers will also be saved so that theimage can be
displayed with the settings in effect when its picture was taken. All
images taken by the CAMERA will be stored in a compressed format and are
directly usable by PRESENT version 7. (Note: Text mode screens and CGA
mode graphic screens are can be used by version 6)
The camera's "film" consists of a file name patterns with an optional
drive and path address. The name pattern is a valid filename only 6
characters long. Pictures will be stored in a file whose name begins
with the 6 characters of the pattern followed by a two digit number
which will be incremented every time a picture is taken. The extension
will always be forced to .PIC. If less than 6 characters are specified
in the pattern, zeros will be added to the right. However, the count
will always be between 00 and 99. If more than 100 pictures are taken
the number will be reset to 00.
Version 7.0 of CAMERA has a number of new features that will allow
greater flexibility in its use. Its principal new feature is its
ability to capture screen images even while DOS is busy, and store them
on disk at a later time when it is safe to do so. Version 7 of CAMERA
will now support paths, and has a user-reconfigurable hot-key
combinatiom for the "shutter".
To be able to capture screen images while DOS is busy makes it possible
to capture screen images that have been very difficult, if not
impossible to capture before. To do this CAMERA sets up a memory buffer
where it will store its image file until it is safe to write it to disk.
The buffer size can be set between 4 and 60K bytes upon installation.
If no buffer size is specified, it will default to 32K. When the
"shutter" is pressed, it will inmediately take the contents of the active
screen buffer and dump it into the buffer. It then checks to see is DOS
is active, if DOS is doing anything it will wait before attempting to
write to disk.
While capturing graphic screens in the high-resolution EGA mode, 640 x
350, 16 colors, it is possible to get image file sizes greater than 60K
bytes, even if compressed. If this happens, CAMERA will alert you that
it was not able to handle that picture size. A version of CAMERA
without the buffer feature is available for such situations.
ECAMERA.COM will not be able to take pictures while DOS is busy, but
will handle most situations directly, as dis earlier versions of CAMERA.
For all other purposes, ECAMERA.COM operates in the same way.
The command format is as follows:
To Install CAMERA:
CAMERA [Drive] [Path] filemask [/nn]
Drive and Path are optional, if not provided, the default
drive is used and the path in use while writing will be
used. Before installing itself, CAMERA will check for the
existence of the specified path. To do this, it will
create and erase a file called xxxxxx00.pic (the pictures
now start with xxxxxx01.pic).
Filemask is the normal 6 character mask.
/nn is also optional and is used to indicate the buffer
size anywhere from 4 to 60, if no value or one outside
this range is given, a default size of 32k will be
Once installed, the following commands can then be issued, during all of
these, CAMERA will check for pending pictures.
To turn the CAMERA on or off:
To capture a screen image:
Press the ALT-TAB key combination. This is the "shutter".
You will hear a small squeek that tells you that the picture
was successfully taken.
To change the CAMERA's film:
CAMERA [Drive] [Path] filemask
Please note, you cannot re-size the buffer, you must
first remove CAMERA and then re-install with a different
To change the Hot-key
You will be prompted to press the key you want to use.
You can only press the 'target' key. For example if you
want to use Alt-p as your hot-key, you press the 'p'. If
you press a key combination or a key it doesn't like, it
will ask you to retry. The hot-key is always an Alt- x
combination. (if you press the current hot-key while in
this sequence, guess what ? you will take a picture!).
Present CAMERA users please note: the use of the shift
key, if you press alt- you will take a picture of
the current screen in use. If you press alt shift
then you will force a picture of the MONOCHROME
screen (if any). There is no way to safely assume a mode
for a Color display.
This command will change the default screen selected by the
alternate shutter. Enter CAMERA /A and the program will provide
To remove CAMERA
If pictures are pending to be written out, and you were
not successful in the retry, CAMERA will warn you that
you will be removing it with pictures in the buffer and
give you a chance to change your mind.
CAMERA will only uninstall itself if it finds that Int 9
and int 21H have not been changed since it was installed.
If so, it will NOT remove itself. Therefore, you must
first release the other programs to remove the CAMERA
successfully or reboot it if that cannot be accomplished.
Since CAMERA may take a sizable chunk of you memory, it
is advisable that you install it last. If in effect, there
was a TSR program installed after CAMERA that doesn't
modify the mentioned vectors, CAMERA will uninstall
itself, but leave a gaping hole in storage.
If CAMERA detects that DOS is busy and cannot store the image files
directly to disk it will wait, takes over control as soon as DOS becomes
free and stores the contents of the buffer to disk conserving the number
sequence of the pictures. Now, if an error occurs while writing the
pictures, (i.e a disk full condition), it will produce 3 loud beeps and
the pictures that were successfully saved will be removed from the buffer
and those remaining will be re-arranged within the buffer in order to
free up space. The camera will then disable picture writing to avoid
constant interruptions knowing that something went wrong.
The next time you press the shutter, it will store the new picture into
the buffer and retry writing it out. If again it isn't successful it
will again disable picture writing.When the buffer fills up you will
get 3 beeps instead of the small squeek to indicate the problem.
Now, regardless of whether the buffer is full or not, if there is a
picture waiting to be read and you issue a CAMERA command, it will
attempt to write the pictures out and tell you if there was a problem so
you can try to fix it and request a retry. If for example, the problem
was that your hard disk was full, you can change the file mask and the
pictures will be written out to the new location.
CAMERA is copyright (C) 1985,1986, 1987 by SML Services, Inc.
All versions of CAMERA are not public domain software, nor are they free
CAMERA is part of the PRESENT Slide Presentation System and its use is
encouraged by existing PRESENT users. If you are not familiar with
PRESENT and wish to know more about it, write for information to:
SML Services, Inc.
6095 River Chase Cir.
Atlanta, Georgia 30328
If you have any questions concerning revisions, updates, or information
concerning any detected "bugs" or incompatibility problems, please drop
us a line or call on the telephone.Technical support is limited to
registered PRESENT users only.
You are encouraged to use CAMERA and to share it with others, on the
1. This note be included in all copies,
2. The name "CAMERA" must be retained,
3. The Copyright and authorship notices contained in the
program and documentation are not to be altered or removed.
4. The program is not to be distributed to others in
5. No fee is to be charged for copying or distributing
the program. Exceptions to this rule are made for non-U.S.,
non-profit, clubs where BBS may not be a viable method of
distribution. Clubs will be allowed to charge a reasonable
charge for distributing a disk with all the program files.
User groups, clubs and BBS's are encouraged to distribute the program
and documentation, subject to the above limitations.
IN ANY CASE NO COMMERCIAL OR MONEY-MAKING VENTURES WITH REGARD TO
SOFTWARE SALES OR MODIFICATION AND THE SUBSEQUENT SALE OF THE CAMERA
PROGRAM IN WHOLE OR ANY PART IS PERMITTED.
SML Services, Inc.