HP (Hewlett-Packard) HP-42S manual

An alternative HP-42S/Free 42 Manual (Version 0.6) 2005 Author: José Lauro Strapasson, Brazil. jlstrapasson@uol.com.br http://joselauro.com/42s.pdf[...]

Index Index 1 Introduction 2 Basic Operations 3 Memory 4 Probability 5 Complex numbers 6 Programming 7 Using the Solver 8 Numeric Integration 9 Statistics 10 Matrices 11 Other Bases 12 Flags License for this manual[...]

1 Introduction Since HP-42S was a very nice calculator, and its official manual is no longer freely available and there were many people looking for its manual, seemed good to me to write my own HP-42S manual. I personally don't have a HP-42S (more than U$300 on ebay). I have a HP-33S and had a HP-48G, but my brother has one and I also use Fre[...]

2 Basic Operations 2.1 RPN HP-42S as most old HP calculators was a RPN calculator. RPN comes from “Reverse Polish Notation”. In RPN we first enter data and then we enter the mathematical operations. Example: To make a simple operation like 2+2 in a normal algebraic calculator we do 2 + 2 = which give to us 4. To make this using a RPN calculator[...]

So algebraic calculators are ambiguous because the many ways they work. RPN calculators are more standard and so less ambiguous. The main key to understand how to use RPN in more complex calculus is to realize that in RPN we make calculations from “inside” to “outside” instead of from left to right. Example: 8 x ln[5+sin(40)] in RPN is doin[...]

IMPORTANT : For sake of simplicity sometimes we will use / instead of ÷. 2.5 Menus Not all functions of HP-42S are visible above the keys. It has menus with much more functions. The menus are ALPHA , MODES , DISP , CLEAR , SO LVER , ∫f (x) , MATRIX , STAT , BASE , C O N VERT , FLAGS , PROB , CUSTOM , PGM. FCN , PRINT , TOP.FCN and CATALOG . 2.6 [...]

1.41421356237 As you can see the numbers are not truncated but rounded. Not all numbers can be seem with a fixed decimal precision. If you put 4 digits for fixed precision the number π will appear as 3.1416 but if one calculate 10 8 (do this by doing 8 ▀ 10 x ) what you are going to see is 100,000,000.000 with 3 decimal digits. This happens beca[...]

make the calculator to use ',' for decimal point and by pressing RDX. we make it use '.' for decimal point. Again the active mode is followed by a ■ sing. Here, in this manual, I suppose the calculator using '.' for decimal point. 2.6 MODES Menu To access MODES menu just press ▀ MODES. (MODES is above +/- key). DEG[...]

this case the content just entered appears only once. So if you do 2 1/x or another example 9 √x what you will have will be i) Only the content of the line 4 (line t) will be lost. ii) The content of line 3 (z) goes to line 4 (t). iii)The content of line y goes to line 3 (z). iv) The content of line x goes to line y. v) Your result will be in the[...]

LN and ▀ e x : These functions calculate the base e=2.71828... loga rithm and it's inverse. Unlike LOG these are very, very important functions! But what about if we want a logarithm in another base? It would be nice to have a special key for this but it is just about remembering that log x y = log z y / log z x where z is any other base. If[...]

ABCDE FGHI JKLM NOPQ RSTUV WXYZ These are sub-menus. If you press now ABCDE what you will have is A B C D E Then just pick the letter you want. But above you can see this symbol ▼▲ . This symbol means the menu has more than on line. You can access the other lines by pressing ▲ or ▼ . In this case there is just one more line with Ă , Å and[...]

3 Memory The real HP-42S has about 7200 bytes of memory while Free42 can have much more depending on the available memory in the computer/handheld. In fact, 7200 bytes is a lot of memory for HP-42S! A program of 10 lines uses about 15 bytes of memory. This means that while in some other models like HP-20S you would be able to program just 99 lines [...]

Actually is not just PI you type but NOPQ P FGHI I but we wrote that for simplicity. Now to get this number back it is just type RCL “PI”. When you type RCL the “PI” should appear to you select it. You can also use STO+, STO-, STOx and STO÷ even in this case since the types of the things you are operating are the same. We can deal with the[...]

3.3 The ▀ CUSTOM menu This is not related to memory but as we saw the FCN function in the CATALOG menu we are already able to talk about it. The HP-42S calculator has a lot of functions. And it is not a good idea to find the function you want every time in the FCN or to use every time XEQ “function name”. To solve this problem HP-42S has the [...]

4 Probability Probability functions are in ▀ PROB menu (over x key). They are COMB , PERM , N! , GAM , RAN and SEED . COMB : This calculates the number of combinations of N things taken r at a time. The order does not matter. A thing cannot appear more than one time. Example: If we have the five letters a , e , i , o and u the possible combinatio[...]

For a integer number we have Γ(n)=(n-1)! and Γ(n+1)=n!. The number in gamma function must be real. In this point HP-42S is different from 33S which has only one function for both things. RAN : This is the random number generator which gives a pseudo-random number in 0≤ x ≤1. SEED : A sequence of pseudo-random numbers always starts with a seed[...]

5 Complex Numbers 5.1 Complex numbers in rectangular coordinates. Unlike the HP-33S (and its ancestor HP-32SII) complex numbers are straight supported and used in HP-42S. There is almost nothing special to say. Just enter -1 and press √x, what are you going to have is x: 0.0000 i1.0000 which means i. (Just to you have an idea to do the same in HP[...]

6 Programming Programming in HP-42 is very simple. It does not use RPL style of HP-48 or HP-49. You program in the same way you use the calculator and unlike some non hp cheaper calculators all the steps are shown in the display and in numbered lines. 6.1 Basic programming. Let's imagine you want to make a given calculation. For example: Suppo[...]

RCL 00 x ÷ So what about if you have to solve more 100 of this kind of equation? Only changing the a , b and c values? It would be better to save all the steps in the calculator's memory and let it do the calculations for you. This is what calculators programming is about. To enter in the program mode you must do ▀ PRGM (above R/S key). If [...]

1 STO 00 5 +/- STO 01 4 STO 02 Now we just press R/S (to run the program) and we get 1, and pressing it again we have 4. 6.2 More than one program in the memory. If we want to have more than one program in the memory we can use more than one program space. To create another program space just press ▀ GTO .. The ▀ GTO command can be used in two [...]

When in programing mode XEQ function is programed and when the program finds the XEQ function it changes to the given program which must finish with RTN function. So LBL “label” and RTN makes a kind of procedure and after the procedure is run it goes back to the previous position. Example: 01 LBL S 02 + 03 RTN 04 LBL A 05 5 06 ENTER 07 7 08 XEQ[...]

works normally and if not the program jumps one line. The X?Y functions work in the same way but now the condition is about the lines x and y of the stack and not only about line x. Example: A kind of “timer” 01 LBL A 02 1 03 - 04 X=0? 05 STOP (Enter R/S) 06 GTO A 07 RTN In this program you first enter a big integer number and then press XEQ ?[...]

7 Using the Solver Unfortunately the HP-42S does not have an equation editor like the 33S one. To use the solver and numeric integration we must enter the equation in a program which must have a global name. Let's suppose we want to solve the equation x 2 − 5 x  4 = 0 . We are going to enter it in a program. For example: 01 LBL “FX” ([...]

15 + 16 END When we leave the program mode and go to Solver menu again we select FX program and what we are going to see is A B C X Now just enter the values of A, B, C and a start value for X and we are done.:) Some interesting things to say are: 1-We can't find complex solutions. 2-In this particular case we are not limited to the case a≠0[...]

8 Numeric Integration Suppose we want to solve numerically a integral of the form ∫ a b f  x  dx we write the function in the same way we did in the solver case. Example: Calculate ∫ 0 1 x 2 dx . First we enter the function as a program 01 LBL “FX” 02 MVAR “X” (also available in ∫f(x) menu) 03 RCL X 04 X↑2 05 RTN 06 END Then w[...]

9 Statistics To enter statistical data we use the function Σ+ . For one variable statistic just enter the number and press Σ+. For two variables statistic first enter y, press ENTER and then enter x (without pressing ENTER!) and finally press Σ+. To clear statistic data just do ▀ CLEAR CLΣ . The statistical functions are available in ▀ STAT[...]

Let's start from MODL which is a “sub-sub-menu”. It has LINF , LOG , EXPF , PWRF and BEST . If the LINF is active the calculator will try to fit the data in a y=Mx+B model. If the LOG is active the calculator will try to fit the data in a y=M lnx+B model. If EXPF is active the model is y=B exp{Mx} and PWRF is y=B x^M. How can I select the [...]

10 Matrices Despite of its small display one of the nice features of HP-42S is the ability to work with matrices. This is done using basically the ▀ MATRIX menu. This multi-line menu has the following items: NEW , INV , DET , TRAN , SIMQ , EDIT DOT , CROSS , UVEC , DIM , INDEX , EDITN STOIJ , RCLIJ , STOEL , RCLEL , PUTM , GETM Let's start f[...]

Exercise: Calculate the determinant of this matrix: First line: 1 2 3 Second line: -2 3 5 Third line: 0 4 -1 Solution: First we create a 3x3 matrix 3 ENTER ▀ MATRIX NEW We have x: [ 3x3 Matrix] in the display Now we press EDIT and we have 1:1=0.0000 Let's enter all elements. (First line) 1 → 2 → 3 Let's go, for example to (2,1), to [...]

you enter the real part then you enter the imaginary part and then you press ▀ COMPLEX . As here it is not a normal sum but a matrix sum we have to enter two matrices of the same size. In fact one can create an empty complex matrix and then edit it. Example: To create a 3x3 complex matrix we do (with matrix menu active) 3 ENTER NEW ENTER ▀ COMP[...]

11 Other Bases To work with other bases we must use the ▀ BASE menu (over the “4”). This menu has the following functions: A...F : Select hexadecimal mode and show A to F. HEXM : Select hexadecimal mode. DECM : Decimal mode. OCTM : Octal mode. BINM : Binary mode. LOGIC : Show the logic functions AND , OR , XOR , NOT , BIT? , ROTXY . Example: [...]

12 Flags The HP-42S has 100 flags from 00 to 99. A flag is a “binary memory” which works as an indicator of calculator's status. A flag can be “set”(true) or “clear”(false). Just for comparison 33S has only 12 flags. But why do we need flags? Why not set up the calculator status using just the default menus? For me the most interes[...]

An alternative HP-42S/Free42 Manual (Version 0.6) 2005 Author: José Lauro Strapasson, Brazil. LICENSE This manual is available as is without any warranty. It can be printed, put in web sites to download, freely used, etc, but cannot be translated or changed without author's permission (except for personal use).[...]