Through The Looking Glass

Ed shows how to use Windows 3.1 on your desktop to customize your 95LX TopCard opening screen.

By Ed Keefe

Using Windows 3.1 Paintbrush Program to Create TopCard (PCX) Files

Are you getting tired of the same old TopCard on your 95LX? Would you like to have a TopCard of your own design? Perhaps something that looks like your business card?

If the answer is yes, then you might like to try your hand at designing just such a card. Here is a recipe for creating a unique TopCard file using the Paintbrush program from Windows 3.1.

Activate Windows 3.1. and double click on the Paintbrush icon. When Paintbrush is active, pull down the Options submenu and select Image attributes to change the size of the drawing area .

Go to the Units box of the Image Attributes dialog box and click on pels. In the Colors Box, select Black and white. Set the width to 240 and height to 128. Click [OK] to lock this in. You should see a small rectangular box in the upper left corner of the work area.

Windows Paint Program After Resizing the Drawing Area:  Graphic

 Use one of Paintbrush's drawing tools, or select Text Fonts to enter text into the picture. Remember that black and white will be reversed on the HP 95LX. If you want to have black text on a white background, you have to create white text on a black background in Paintbrush. To create a black background, select the Paintbrush fill icon (shaped like a paint roller). Then click on the solid black box on the color bar. Finally, position the fill icon in the small drawing box and click to fill the entire drawing area with black.

To select white text, click the Text icon on the tool bar (small box with the letters "ABC" in it). Then click the white box on the color bar. Any text you now enter will be white.

Save your work with the .PCX extension and use ZIP.COM (ON DISK ICON) or another file transfer program to transfer it back to the HP 95LX _DAT subdirectory. Go into SET UP (press (<Shift>) (FILER)) and press Owner Picture-File (ESC) and move the cursor to the .PCX file you just created. Exit SET UP and the other built-in applications, and the new PCX file will appear on the screen when you turn the 95LX on.

You can modify your existing TOPCARD.PCX file also. Use ZIP.COM or the APP95 file transfer program to copy TOPCARD.PCX from the 95LX to your desktop. Click File Open and select TOPCARD.PCX. The file will appear on the Paintbrush screen. You can modify and save it as described above.

TopCard File Imported into Paint:  Graphic

 SOME TIPS

Select View, Cursor position and Paintbrush displays the coordinates of the position in the picture you are working on. This may help you keep track of where you are. I've found that setting the attribute to black and picking Paintbrush's fat brush shape lets me erase the whole area in a few sweeps. I also select View, Zoom in and select a portion of the picture to magnify so that I can fine tune the picture, pixel by pixel.

Below is TLG.PCX (ON DISK ICON), a TopCard PCX file I created with Paintbrush.

Customized TopCard:   Graphic

 Transfer the finished picture to the HP 95LX, and use Setup-Owner to make the new PCX file pop-up in place of the normal TOPCARD.PCX file.

If you leave the Owner Filename as C:\_DAT\TOPCARD.PCX and move your new PCX file to C:\_DAT\TOPCARD.PCX, be sure and use Setup to delete any info in the Owner window. Otherwise it will be superimposed on your new TOPCARD. You might also paint the upper right and lower left corners of your PCX file solid black to leave room for the time and date and the "Press a blue application key..." message.

In A Mathematical Mood

While doing research for this month's Programmers' Corner article on Derive, I began to wonder what other math programs would work on the HP 95LX.

Granted, CALC and 1-2-3 will solve many of the real-world math problems that most of us will ever encounter. And, for the true mathematicians, if there is a need for a wayfaring calculus engine, Derive will more than meet that need.

But what about those times when the rest of us encounter math beyond the capabilities of CALC or 1-2-3, or our own level of mathematical training?

If all we want to do is put some numbers in a formula and crank out an answer quickly, then the quickest answer to our problem is to use CALC's Solve routine.

However, suppose you're confronted with a problem that involves the solution of two or more linear equations. You know, the kind of algebra that says, if 4x + 3y = 25 and 16x -9y = 100, what are the values of x and y? Hmmm. CALC solves that kind of problem, but the solution's not that intuitive.

Or, how about something like this? A farmer wants to maximize profit by planting two crops on 100 acres of land. The total time spent planting and caring for the crops can't exceed 160 hours and the second crop takes 4 times as many work-hours as the first crop. The total investment must be less than or equal to $1,200. Typically, the first crop costs $10 per acre and gives $30 profit while the second costs $20 and yields a profit of $100 per acre. The question is: how many acres of each crop should be planted? Don't bother to push the blue CALC key for this type of problem. You might try 1-2-3 instead, but, once again, the solution, though possible, is not something for the mathematically disinclined.

One of the few computer programs that could solve such a problem is an old workhorse from Borland International. The program is called EUREKA: The Solver.

Eureka was released in 1987, and, for its day, it was quite novel. It used a technique of solving math problems by making repeated guesses at a solution and checking to see how close each guess was. It would keep on guessing until it ran out of time or computer memory. CALC uses this same technique to solve some problems that don't lend themselves to a direct solution.

Since I still had a copy of Eureka, I wondered if it would work on the HP 95LX. It took me about half an hour to resurrect it, color it black and white, and resize the display so it would show up in the HP 95LX.

Once it was installed on the 95LX, it took me a couple more minutes to key in the simultaneous, linear equation problem, and push the button to start the solution.

********************************

Eureka: The Solver, Version 1.0

Name of input file: A:\LINEQN.EKA

********************************

4*X + 3*Y = 25

16*X - 9*Y = 100

********************************

Solution:

Variables Values

X = 6.2500000

Y = .00000000

********************************

On the other hand, the solution to the dual crop problem took an astounding two and a half minutes to run to completion.

Here's what the problem and its solution looked like.

*************************************

Eureka: The Solver, Version 1.0

Name of input file: A:\FARMER.EKA

*************************************

P= (30*X) +(100*Y);

$MAX (P)

X+Y <= 100

X+4*Y <=160

10*X+20*Y <=1200

X>=0

Y>=0

************************************

Solution:

Variables Values

P = 4400.

X = 80.00

Y = 20.00

Confidence level = 85.4%

All constraints satisfied.

************************************

If you have access to a copy of Eureka: The Solver, you might want to try the same experiment.

Sad to say, Eureka is no longer being sold by Borland. When the software company decided to focus its energies on spreadsheets and database programs, it released Eureka back to its original author, Roger Shlafly, of Real Software.

Roger has rewritten the program and offers it as a shareware product now called Mercury.

I found a copy of Mercury, version 2.09 on the same bulletin board that serves Derive users.

Mercury has some unique features that might make it useful for the HP 95LX. For example, it's one of the few programs that will let you choose the serial port for printer output. It supports over 30 different printers, including the LaserJet.

Mercury demands a color monitor to produce graphs. However, in the absence of such a display, you can tell Mercury to list the coordinates for such a graph and store the list in a file. The coordinates can then be imported into Lotus 1-2-3 for graphical analysis.

We've included a copy of MRCRY209.ZIP (ON DISK ICON) on The HP Palmtop Paper ON DISK for those who would like to experiment with this program. Mercury requires an 80 X 25 screen, so expect to spend a lot of time scrolling around the small screen of the HP 95LX. Also, as with any new piece of software, be sure to back up everything on your HP 95LX before using it.

If you feel that the program has merit, you might give the author a call and suggest that he modify Mercury for use on the HP 95LX. My first attempt at making such a suggestion met with a cool reception. The price of $49 is not unreasonable.