CALC.TPU (2.0) TP5.X Compiled Unit CALC.TPU (2.0)



UNIT NAME

CALC.TPU - Version 1.0 for Turbo Pascal Version 5.X.

Version 1.0 Released July 30, 1988.
Version 1.1 Released Aug. 15, 1988, corrects window removal.
Version 2.0 Released Dec. 27, 1988. TP5.X and TP4 compatible.


PROGRAMMER


Timothy B. Coleman
11115 Kenmoor Drive
Detroit, Michigan 48205



GENERAL DESCRIPTION


This Unit file will allow a Turbo Pascal Ver. 5.X (TP5.X)
programmer to add a Four Function Calculator to any TP5.X
program with the declaration, "Uses Calc, Meta;". CALC.TPU
contains the calculator "engine" to perform a perfect
emulation of a handheld four function calculator. The unit
can make the result of a calculation available, for
insertion into the application below the calculator window.
Meta is a unit that contains the Metaphor or image of a
calculator.

Three example calculator Metaphor tpu files and the source
code are included, or the developer may create its META.TPU,
using one of the included files as an example. The
programmer then decides whether or not a calculator
metaphor, key help screen, or simply a small window, where
only the numbers entered and results are displayed, is
appropriate for the given application. Or the programmer
may decide to give the user a choice of a small window or a
metaphor in the programs installation procedures.

The programmer can elect to use the unit in its default form




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CALC.TPU (2.0) TP5.X Compiled Unit CALC.TPU (2.0)


by binding it to a key and calling the procedure
"Calculator", in much the same way a help screen might be
called.

The CALC.TPU defaults are:

* Do not wait for retrace.
* Window border color is white (15).
* Calculator display is white.
* Keyboard number lock is set on.

When calling the calculator, the current screen (CGA, MONO,
EGA, VGA, MCGA, 80 column text mode only) is saved and a
window is opened displaying whatever the developer decides
the installed calculator should look.

OPERATION

The window can be moved across the screen in five
character-cell steps, to allow any on screen values to be
seen from the application below. The normal numeric keys
and +, -, /, and * perform the normal four functions, and
the c, e =, or provide Clear all, clear Entry, and
total functions. The right and left arrow keys move the
calculator window on the screen. On the enhanced keyboard,
the cursor pad will allways be "on", but on the older
keyboard the cursor and numeric functions are shared. If
EnhncdKeyboard is set to FALSE, then the user will
automatically have the number pad turned on. The shift key
must then be pressed to use the right and left arrow keys to
move the calculator across the screen.

The user may return to the application by hitting the escape
key. When the calculator is called upon for later use, the
last calculation is still intact and it returns to the on
screen position last set by the user. The programmer may
write code (see the example in SAMPLE.PAS) to utilize the
value placed in the variable "PasteValue", when the exit is
performed by the F10 key from within the calculator.

FLEXIBILITY




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CALC.TPU (2.0) TP5.X Compiled Unit CALC.TPU (2.0)


By managing its own window, CALC.TPU frees the programmer
from additional interface requirements. Developers wanting
to control window management must purchase the source code.

Screen colors, number pad control, and "wait for retrace"
may be set by the programmer, or by the user if the
programmer has a general installation procedure. The
calculator has an exit flag (PasteExit : Boolean;) to allow
the programmer to determine if the users exit requires a
value (PasteValue : String) be pasted into the application.

By purchasing the source code, changes can be made in the
code to allow its use across networks, utilize a numeric
coprocessor, or it may be modified for use in XENIX
applications using one of the PASCAL compilers available for
that Operating system (I read somewhere that BORLAND may
port its languages to XENIX or UNIX and that OS2 versions
were coming soon).


LICENSE REQUIREMENTS

CALC.TPU UNIT LICENSE

A developer wishing to compile the unit, CALC.TPU, into an
application may do so by completing the License application
in this ARC file and returning it with a Check or Money
order for Twenty Dollars ($20.00). The developer may use the
unit, CALC.TPU in any number of applications for private or
commercial use. There are no royalties or other fees for
the use of the unit CALC.TPU in an application. CALC.TPU
may not be distributed with any other software unless in the
form of the full ARC file, with all sample files, CALC.TPU,
META files, license form, and this documentation file
present.

CALC.PAS SOUCRE CODE LICENSE

The source code to CALC.TPU may also be purchased for Sixty
dollars ($60.00). The license form must be completed and




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CALC.TPU (2.0) TP5.X Compiled Unit CALC.TPU (2.0)


returned along with a check or money order for Sixty dollars
($60.00). When purchasing the source do not send any
additional for the TPU. The source license includes the
TPU. Purchasing the source code allows one to add other
features such as memory variable keys, percent key
operation, number base conversion, paper tape printing to
file, printer or screen, slide rule functions, and other
features. The source will be delivered on 5 1/4", 360K, IBM
compatible floppy or on 3 1/2", 720K, IBM compatible floppy,
or on both for an additional $3.00. Also included with the
media is a fully commented source listing with cross
reference for all label, constants, types, variables,
procedures, and functions.

Also available in source code form is the same calculator as
an include file for Turbo Pascal Version 3 (TP3). This
include file adds approx. 5k to an executable TP3 program.
The cost of this file is Sixty dollars ($60.00).

The source code to CALC.TPU, and the TP3 version, CALC.INC,
remains the property of Timothy B. Coleman and may not be
distributed in printed or electronic form, or on magenetic
media, or any other media. It is the responsibility of the
programmer using this source code to respect its proprietary
nature.

Upon receipt of your license application, a registration
form, and source code for those requesting it, will be
mailed within two days.

The META files, both source and TPU, are available with the
SHAREWARE release of CALC.TPU, and may be modified freely.

Following the simple methodology used by the calculator, a
programmer may add many additional functions suitable for
the specific application being designed. Purchasing the
source will also allow simple recoding to support terminals
and network applications.


INTERFACE




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CALC.TPU (2.0) TP5.X Compiled Unit CALC.TPU (2.0)


The unit file has the following interface:

Uses
Crt,
meta,
cursors,
fastWr;
Procedure Calculator;
Var PasteValue : String;
{Contains the result of a calculation.}

PasteExit : Boolean;
{Flag indicating the result should be pasted.}
KillSnow : Boolean;
{If set to TRUE screen writes wait for retrace.}
BoxTint : Integer;
{Color of the window border.}
ValueTint : Integer;
{Color of number written to the display}
EnhncdKeyboard : Boolean;
{If set to TRUE number locks not turned on.}

Unit name: CALC
Total code: 3495
Initialized data: 72
Uninitialized data: 5594
Symbol table: 773
Relocation table: 3168
Line number table: 0
Numeric processing: $N-


ACKNOWLEDGEMENTS

The sometimes unpredictable and inconsistent operation of
the TP5 Write and Writeln procedures, led me to the decision
to utilize Brian Foley's SUPER! Public Domain procedure,
FASTWR.TPU. This file (FASTWR.ARC) is available on
CompuServe in the Borland Library (GO BOR-100, LIB 2).




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CALC.TPU (2.0) TP5.X Compiled Unit CALC.TPU (2.0)


FASTWR is used to draw the window and to display entered
values and results on the screen. FASTWR writes to the crt
much faster than TP5.X's own Write and it allows positioning
and color selection in one command. I also used FASTWR in
the META file for the calculator image or metaphor. I
suggest the use of FASTWR.TPU in any programmer created META
file, but other routines should work fine. If you cannot
find FASTWR.ARC or did not get this file from CompuServe,
include a note, when you mail your license form, requesting
a copy and I'll send it with your Registration form.

Also utilized, is the Public Domain routines in CURSORS.TPU
by Scott Bussinger, Professional Practice Systems, ver.
1.02. CURSORS.TPU is used in CALC.TPU to blank the cursor
during calculator use, and to retore it and its original
position after use.

Thanks to Brian Foley and Scott Bussinger for writing those
fine routines.


APPLICATIONS

Now that TP allows the executable program to be up 640K, it
is easy to build a friendlier, more complete application.
The addition of a calculator may at first thought seem to be
rather a rudimentary improvement. With cheap four function
calculators costing about five bucks ($5.00), why worry
about adding one to an application? Probably the best
justification is that a user cannot paste the result of a
calculation from a handheld unit into the application on
screen. The possibility of making an error in transfering
the number is eliminated. Popup windows have proven to be a
popular way of presenting information, and a useful way of
doing something else while in the context of a prior task.
Many applications can benefit from the addition of this
professional appearing, windowed calculator. The changes
can be made to most TP5.X programs in 5 to 15 minutes! Here
are some example applications:

* Point of sale software.
* Payroll Programs





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CALC.TPU (2.0) TP5.X Compiled Unit CALC.TPU (2.0)



* Accounting Packages.
* DataBase management software.
* Word Processing software.
* Text Editors.
* Communication Software.
* SpreadSheet programs.
* Project management Software.
* Desktop management applications.
* Integrated Software (call from any part of the program).

Remember also that while TSR programs, along with
sophisticated environments such as MicroSoft Windows, all
provide built in calculators, these programs can use vast
amounts of memory and may not work smoothly with your
application. It has also been stated that TSR programs
should not be used in the Compatibility Box under OS2. TSR
programs also do not work well in environments like
PC-MOS/386. It is therefore more important that your new
application include proven, useful desktop applications such
as CALC.TPU.

FILES

Files included in the ARC file are listed below:

CALC TPU - The calculator unit.
CALC DOC - This documentation file.
META1 PAS - A metaphor of a large handheld calculator.
META1 TPU - The compiled unit.
META2 TPU - The metaphor of a small handheld calculator.
META2 PAS - The compiled unit.
META3 TPU - A tiny window at the top of the screen.
META3 PAS - The compiled unit.
READ ME - Read this file FIRST.
SAMPLE EXE - A sample program demonstarting all Features
SAMPLE PAS - Source for the sample executable.
LICENSE FRM - The license form to be printed and mailed.
PRINTDOC BAT - A batch file to print this file and the
license.
All source code is completely commented to insure that you
can implement CALC.TPU into your application in MINUTES!!





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CALC.TPU (2.0) TP5.X Compiled Unit CALC.TPU (2.0)


COMPILING

To compile CALC.TPU into an application, you must rename one
of the meta files from meta1, meta2, or meta3, to meta. If
you are compiling one of the meta source files you must have
FASTWR.TPU (or recode to support your choice of display
routines.) where the compiler can locate it, along with
CALC.TPU. Read the file SAMPLE.PAS to see how things are
coded.

The keyboard buffer is the perfect place to send alpha
numeric charcters from the calculator. One method of doing
this is listed below:

PROCEDURE BufIn(PushInt : Integer);
BEGIN
INLINE
($1E/
$B8/$40/$00/
$8E/$D8/
$FA/
$8B/$46/$04/
$8B/$1E/$1C/$00/
$89/$07/
$83/$C3/$02/
$3B/$1E/$82/$00/
$79/$07/
$89/$1E/$1C/$00/
$EB/$09/$90/
$8B/$1E/$80/$00/
$89/$1E/$1C/$00/
$FB/
$1F);
END;

This code was captured from a Borland forum discussion and I
cannot remember whom to credit.

FOR index := 1 to Length(LastOper) DO
BEGIN
PushInt := Integer(PasteValue[index]);
BufIn(PushInt);
END;

The code fragment above is used to stuff characters one at a
time, into the keyboard routine, BufIn. One other simple
method of stuffing the buffer is given in the file KBD.ARC
on CompuServe's Borland SIG in LIB 2. Any number of methods
may be used to put the result of a calculation into your



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CALC.TPU (2.0) TP5.X Compiled Unit CALC.TPU (2.0)


application.

After reading the file SAMPLE.PAS, you may want to change
the colors, set the variable, enhncdkeyboard, for your type
of keyboard, and rename one of the meta files and recompile
to see first hand how easy it is to make the calculator look
any way you wish.


HISTORY

CALC.TPU was originally a procedure I wrote for a custom
Database mgmt. and billing system I was designing, for a
market that shall remain unnamed since I have don't
presently have any competition. It worked so well that I
decided to convert it to a stand-alone TP3 program and make
it PUBLIC DOMAIN. Within months, I had moved it into a TSR
calculator (also PUBLIC DOMAIN). Both went through several
revisions and with user feedback, small bugs were identified
and eliminated. Enhancments were added with every release.
Both programs are still available on CompuServe's IBMSW
software forum in LIB 12. The programs are FFC45.ARC and
FFNC74.ARC.

What I have delivered to you in CALC.TPU ver. 1.0 is not a
beta file, but a completely debugged, enhanced product,
tested by thousands of users. During the past two years, I
have received countless letters, and Email regarding the
calculator in either TSR or stand alone form. This response
makes believe any application utilizing CALC.TPU can only be
improved by its presence. Try comparing its output to your
own four function calculator.


WARNINGS

The use of TP's floating point emulator has a range of 2.9
X 10E-39 to 1.7 X 10E38, and 11 to 12 significant digits.
While code has been added to prevent divide by zero errors,
it is possible for a user to continually increment a value
with multiplication to the point of forcing an overflow.
This is not a serious event if you use a critical error
handler to intercept errors in a controlled manner. When an




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CALC.TPU (2.0) TP5.X Compiled Unit CALC.TPU (2.0)


error occurs, the critical handler can take over and
promoptly close all open files and allow an orderly shut
down. Under these circumstances, the user should be able to
restart with no loss of current data. Code is available on
CompuServe in the Borland SIG (LIB 1) from a back issue of
Turbo Technix Magazine that provides excellent code
fragments from which a programmer can build a useful error
handler to suit the application.


Mail license forms and fee to:


Timothy B. Coleman
11115 Kenmoor Drive
Detroit, Michigan 48205































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