Contents of the LENS.DOC file
Lens 1.03 : A Windows Magnifier
(c) 1992 by Ned Konz [BIX: nkonz, CIS: 76046,223]
This is a Windows version of an Amiga program I wrote in 1985. It was
written in C++ and compiled with Zortech's C++ compiler, under OS/2 2.0.
I will probably port Lens to OS/2 2.0 Presentation Manager.
Interestingly, the Windows version of Lens runs about as fast on
a 25 MHz 80386 as the Amiga version did on a 7 MHz 68000.
I think this is because I am using the Windows StretchBlt() call
to do the magnification here, instead of my optimized magnification
routine on the Amiga. Future versions of Lens for Windows will probably
magnify faster using this routine.
If you feel this program has value to you, I'd really
appreciate a payment of $5.00 US sent to me at:
161 14th St.
Holly Hill FL 32117, USA
Lens normally magnifies an area of the screen around the mouse cursor.
It can additionally try to track the caret (the "text cursor") in
text applications, if you enable Track Caret mode.
You can try Track Caret mode with Notepad. This mode does
not work with all applications. It will not work, for instance, with
Word for Windows, which doesn't use the built-in Windows calls for
displaying and moving the caret. Also, since it is impossible for Lens
to tell whether the caret is actually being displayed, this setting
may cause a lack of Lens motion when a non-text program is active.
Lens will track the mouse cursor if the caret position in the active
window is at the upper left hand corner (0,0), otherwise it will track
Repeat mode continues to magnify even if the cursor has not moved.
This mode should be set if you wish to magnify contents of a window
which are changing on its own without the mouse or the caret being moved,
for example when magnifying animation. This mode may be a resource hog
and slow down your system if the timerInterval setting is too short
The magnification may be changed with the Zoom In (+) and Zoom Out (-)
menu choices. The available range is from 1X to 20X.
You may choose to display or hide the Lens menu bar.
Lens saves its settings in its initialization file when you
choose "Save Settings!". This initialization file may be named as a
parameter to Lens , otherwise it will default to "LENS.INI",
in your Windows directory.
The "timerInterval" setting in this initialization file
sets the minimum time between magnifications (in mSec). Setting it too
low, especially with repeat mode ON, will cause your system to slow
A default LENS.INI (for VGA) file follows (with comments)
; top, left, right, and bottom are the initial position of the lens window.
; these default to 0, 0, screenwidth/2, and screenheight/2.
; this is the initial magnification (1-20)
; repeatMode and trackCaret are either 1 or 0.
; timerInterval sets the minimum time between magnifications.
; it defaults to 500 mSec (1/2 second)
; setting this to 0 inhibits the display of the menu bar in the Lens
================================ Release Notes
* Version 1.03, 8 August 1992
My first bug report! Fixed bug where repeat mode was never saved.
Also made it so that changing magnification from the keyboard using
the + and - keys would cause a window repaint. So now you can leave
your mouse alone and use the + and - keys to get the magnification you
* Version 1.02, June 1992
Changed text of About box.