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Text File | 1985-11-03 | 21.3 KB | 384 lines

Turbo Calc v4.0 Copyright (c) 1985: by P & M Software Co. Turbo Calc is "User Supported" software. If you like the program, use it, and want to see it supported and improved in the future, a contribution of $20 would be appreciated. Please copy and share this program with your friends, even if you are unable to make a contribution. Send Contributions to: P & M Software Co. 9350 Country Creek #30 Houston, Tx 77036 Turbo Calc is intended to be powerfull, yet easy to use. It supports a medium sized spreadsheet, 511 rows by 48 columns. And supports many math and financial functions. Hopefully the user can begin using the program without reading a lot of documentation, but some information is necessary before one can begin. The program requires a minimum of 256k and can use as much as 640k. First, let us examine the layout of the worksheet. On screen, there will be displayed 7 columns by 21 rows. The user may scroll both vertically and horizontally. The vertical scroll is accomplished by depressing the PgUp or PgDn keys. This will scroll 20 rows up or down, a single line scroll is achieved by moving the cursor off the top or bottom of the screen, with the up or down arrow keys. The horizontal scroll is achieved by depressing the Ctrl key and the left or right arrow keys simultaneously. On the top and bottom lines of the screen there appears some status information: the current cell, the amount of memory available, the auto-calc indicator, the current marked range, the current drive and directory, the CAPS and NUM lock indicators. On the second line of the screen will appear messages and the numeric or formula content of the current cell. In general, the user may move the cursor to whatever cell he desires, and enter the text, number or formula that needs to be in that location. If entering text, it can overwrite cells to the right, but may not be longer than 80 characters. When you begin to enter something into a cell, the first keystroke is VERY important. It will determine the type of item stored in the cell: formulas begin with the '(' character, numbers with 0 thru 9, '+' or '-', text with any other character. When making the first keystroke of a cell, some keys have different meanings, than on succeeding keystrokes. For example, the left and right arrow keys will move the cursor around the worksheet, but during the entry of data into a cell, these keys will act to move the cursor within the cell, to edit the data. Other keys that behave differently, are the Home, End and Esc keys. The Home and End keys move the cursor to the beginning or the end of the worksheet, but during the entry of data, they move to the beginning or end of the current cell. Also during data entry, the Esc key will act to finish the entry and move to the cell below, so that a column of numbers may be entered with the Num Lock turned on. If you depress the Esc key, while not entering data, a list of commands will appear, any of the displayed commands may be executed by pressing the indicated letter. For experienced users, the commands may be entered directly, without using the Esc key, by pressing the Alt key and the command letter together. Following are two lists. The first is a list the the cursor control and editing keys. The second is a list of the command letters. Action Action Key Name During Data Entry Otherwise ------------------------------------------------------------- Up Arrow | Finish entry and | Move to cell above. | move to cell above. | ------------------------------------------------------------- Down Arrow | Finish entry and | Move to cell below. | move to cell below. | ------------------------------------------------------------- Left Arrow | Move 1 character to | Move to cell on the | the left. | left ------------------------------------------------------------- Right Arrow | Move 1 character to | Move to cell on the | the right. | right. ------------------------------------------------------------- Home | Move to the start of | Move to cell at the | the cell. | start of worksheet. ------------------------------------------------------------- End | Move to the end of | Move to cell at the | the cell. | end of worksheet. ------------------------------------------------------------- Ctrl + End | Erase contents of | Erase current cell | cell from cursor to | entirely. | end of cell. | ------------------------------------------------------------- Ctrl + L. Arrow | Finish entry and | Scroll to the left. | scroll to the left. | ------------------------------------------------------------- Ctrl + R. Arrow | Finish entry and | Scroll to the right. | scroll to the right. | ------------------------------------------------------------- Tab | Finish entry and | Move to cell on the | move to cell right. | right. ------------------------------------------------------------- Shift + Tab | Finish entry and | Move to cell on the | move to cell left. | left. ------------------------------------------------------------- Ins | Toggle Insert Mode. | Toggle Insert Mode. | Fat cursor = Insert. | Fat cursor = Insert. ------------------------------------------------------------- Del | Delete character at | Delete cursor at | cursor. | cursor. ------------------------------------------------------------- Backspace | Delete character to | No action. | left of cursor. | ------------------------------------------------------------- Enter | Finish entry. Stay | No action. | in current cell. | ------------------------------------------------------------- Esc | Finish entry and | Displays the command | move to cell below. | menu. | Nice for using NUM | | Lock mode with a | | column of numbers! | ------------------------------------------------------------- Command Table: With Alt key, or preceeded by Esc. Esc brings up the command list. ------------------------------------------------------------- X Exit to DOS. ------------------------------------------------------------- Q Remove command list and return to worksheet. ------------------------------------------------------------- L Produce a directory list. ------------------------------------------------------------- N Change to new directory and/or disk drive. ------------------------------------------------------------- R Read worksheet from disk into memory. ------------------------------------------------------------- S Store worksheet from memory onto disk. Both the R and S commands assume the .SSF extension if the user doesn't specify one. If no extension is desired end the filename with a '.' and no ext- ension will be used. ------------------------------------------------------------- E Erase the current worksheet from memory. ------------------------------------------------------------- G Perform the calculations specified by user formula. ------------------------------------------------------------- P Print the worksheet to disk file or printer. ------------------------------------------------------------- F Change cell format. Each cell may have a different format. The default is leading sign, no comma and no currency sysmbol. You may choose 1 of 5 different formats: dollars, comma insertion, percent, scientific and the default. ------------------------------------------------------------- W The width of each column defaults to 10, but it can be changed with this command to any value between 1 and 30. ------------------------------------------------------------- B Mark the start of the range at the current cell. ------------------------------------------------------------- K Mark the end of the range at the current cell. ------------------------------------------------------------- H The user may specify that columns are to be held on the left of the screen and not horizontally scrolled. 4 maximum. ------------------------------------------------------------- I Insert Row or Column. Formula will be adjusted to reflect their new locations. Absolute addresses may be used, by placing a '0' before the row. For example 'C5' is a relative cell address and would be adjusted if needed, but 'C05' is an absolute cell address and would not be adjusted. ------------------------------------------------------------- D Delete Row or Column. Formula will be adjusted as given above for 'I'. ------------------------------------------------------------- J Jump directly to a cell. Avoid scrolling when you know where to go. ------------------------------------------------------------- M Move the indicated range to the current location. The user is given the opportunity to alter the range specification. Formula are adjusted as above for 'I'. ------------------------------------------------------------- C Copy the indicated range to the current location. The user is given the opportunity to alter the range specification. Formula are adjusted as above for 'I'. ------------------------------------------------------------- A Toggle auto-calculate. If many formulas are in the worksheet, it may save time to turn auto-calculate off, and manually calculate with the 'G' command. ------------------------------------------------------------- Now some discussion about selected topics: 1. Formulas. Formulas are composed of operational symbols, cell addresses, constants, and functions. Each formula is enclosed within parenthesis, like this: (A1+C2+F4). This formula would take the content of the 3 cells and add them together, depositing the result in the cell where the formula is located. The following function are available: Name Description Usage ---- ----------- -------- ABS Absolute value. ABS(p) SQRT Square root. SQRT(p) SQR Square. SQR(p) MOD The remainder of p1 divided by p2. MOD(p1,p2) PI 3.1415926536 PI SIN Sine of angle in radians. SIN(p) ASIN Arc sine. ASIN(p) COS Cosine of angle in radians. COS(p) ACOS Arc cosine. ACOS(p) TAN Tangent of angle in radians. TAN(p) ATAN Arc Tangent. ATAN(p) LN Natural Log. LN(p) LOG Log base 10. LOG(p) E 2.7182818285 E EXP E raised to the p power. EXP(p) NPV Net present value of a series NPV(i,r) of future cash flows. PMT Mortgage payment per period. PMT(pa,i,n) PV Present value of ordinary annuity. PV(py,i,n) FV Future value of ordinary annuity. FV(py,i,n) IRR Internal Rate of Return. IRR(g,r) AVG The average. AVG(r) COUNT The number of items in range. COUNT(r) MIN The smallest number in range. MIN(r) MAX The biggest number in range. MAX(r) VAR The population variance. VAR(r) STD The pupulation standard deviation. STD(r) Note: There is no SUM function, instead use the colon, ":", as discussed below under symbols. IF Choose between two values. IF(t,p1,p2) NOT Reverse true and false values. NOT(t) TRUE Returns the value for true. TRUE FALSE Returns the value for false. FALSE ERROR Returns the value for error. ERROR Where: p,p1,p2 ... Constants, cell addresses or algebraic expressions. i ......... Interest rate, may be any of the items listed for "p" above. Note: all interest rates are stated in their fractional format, i.e. "10% = 0.1". r ......... A range of cell addresses, i.e. "D4..H21". pa ........ Principle amount, may be any of the items listed for "p" above. n ......... Number of periods, may be any of the items listed for "p" above. py ........ Payment per period, may be any of the items listed for "p" above. g ......... A guess at the interest rate, usually between 0.0 and 1.0. t ......... A logical expression whose result is 0.0 for false and non-zero for true. Formulas may be quite complicated, an example is: (A1+SIN(PI/2*(B2-C1))) The only limitations imposed are those of available memory and the fact that no formula may be longer than 80 characters. The financial and trig function are not recusive, for example don't do this: (IRR(IRR(.2,D4..D20),E2..M2)), it won't work very well, if at all. If any of the formulas cannot calculate the answer, for example if you ask for the SQRT of a negative number, then the result will be ERROR and you will see the word "ERR" in the result cell. Finally, a formula may contain the following symbols: ^ Raise to the power. * Multiplication / Division + Addition - Subtraction : Range summation | Logical OR & Logical AND > Greater than test < Less than test = Equal test >= Greater than or equal test <= Less than or equal test These are probably familiar, with the exception of the ":" for range summation. Let's say that you want to sum a column of numbers, beginning at D1 and ending at D20, then this expression would sum the column, (D1:D20). 2. Overwritten cells. Turbo Calc will allow you to make text entries of any length up to a mximum of 80 characters, numeric entries may be up to 11 characters. Any text entry that exceeeds the cell width will automatically lock the adjacent cell on the right. The lock will be relased when the length of the entry shrinks. 3. The Range and the commands that use it. The range is shown on the bottom left of the worksheet screen. It is of the form: cell address..cell address. If you have not set the range, it defaults to the beginning and ending cell of the worksheet. There are two methods of setting the range: 1st, you can make the beginning and ending cells with the B and K commands, 2nd, whenever one of the commands that use the range is invoked, you have the opportunity of changing the range by entering the new range. For example the Copy command will give you a menu with 3 options: Range, Copy and eXit. If you select the Range option, you will be allowed to enter a new range, in the same format as displayed at the bottom of the screen. Here are the commands affected by the range: Copy, Move and Print. 4. Printer Setup. If you select the Print command, one of the options presented on the Print menu is "Setup". If you select the Setup option you will be able to control the margins and dimensions of the printed report. Also, you will be given the option called Control. The Control option allows you to specify printer setup control codes and printer exit control codes. These control codes default to Form Feed characters, but you may specify whatever necessary. The convention for specifying these codes is to use the decimal numbers representing the control codes separated by commas. You can also put plain text in the control strings, if you surround the text with " marks. For example: "This is a control string",12,12 If this was the setup control string, when the print began the program would send the following to the printer: 'This is a control string' FF FF. Of course, the quotes would not be sent, and the FF is just a symbolic way to represent the form feed character. With this method, you may program your printer in whatever way you wish. There are 2 dot commands for the printer. If you put .PAGE in column A of any row, it will cause a page break to occur at that place. The remainder of the row with the dot command will not print. After you have entered .PAUSE in column A of a row, page breaks will cause a pause for you to insert the next page and give you an option to reprint a page or exit the print function. 6. Internal Rate of Return. This function provides an iterative approximation for the interest rate which will produce a zero for the Net Present Value function. The range for this function should include present cash flows as well as future cash flows. The approach to finding the zero is as follows, 14 loops thru the "Bisection Method", followed by up to 6 loops thru the "Modified-False Position Method". Usually the IRR function will converge to within 0.000001. In some instances, where the cash flows turn negative in a later period, there are multiple solutions, however IRR finds the closest one only. Your guess input to this function should be between 0.0 and 1.0. In some cases, the function will not converge, either the solution is too small or too large, in these cases the function will return ERR. Try adjusting you guess and recalculate.