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CHAPTER 10. USER CONTRIBUTIONS This is the fun part of this manual because it shows the human side of F-PC. F-PC is a platform, from which one can launch whatever his imagination carries him. Here you will see how different people use this platform to build a wide variety of programs doing totally different things. Many of them deal with very serious subjects, like object oriented programming, floating point mathematics, etc. Many of them are very lighthearted, drawing pictures, running a clock, printing a banner, and so forth. With such a broad spectrum of topics, you will surely find many programs useful and enlightening. We hope that in seeing these applications, you will also be motivated to polish up some of your programs by adapting them to the F-PC environment and contribute them to this section. In F-PC 2.25 there were a set of .ARC files containing contributions from many users: ZIMMER.ARC Utilities provided by Tom Zimmer. SMITH.ARC Floating pointing packages by Bob Smith. CURLEY.ARC Disassembler by Charles Cureley. TING.ARC Multitasking and other applications by C. H. Ting. SMILEY.ARC Graphics by Mark Smiley. SLICE_FF.ARC Slice data base by Robert Gesswein. MISC.ARC Extended data objects by George Hawkins. MODROW.ARC Clock by Jerry Modrow. TANG.ARC Multiple precision integer math by S. Y. Tang. In F-PC 3.5, only the ZIMMER, SMITH, and CURLEY files are retained in the ZIP format, because there is not enough space on the diskettes and there is not enough time to test all the user contributions on the enhanced platform. The contributions not included will be distributed separately from F-PC by the Silicon Valley FIG Chapter after they are tested and verified. 10.1. FROM TOM ZIMMER Tom Zimmer is the principal author of F-PC, besides many other Forth systems and applications. The files in ZIMMER.ARC are examples of his minor works tailored for F-PC. AUTOFOR.SEQ This file contains the tools to allow automatic forward reference resolution of Forth words. There is a runtime overhead which is equivalent to a DEFERred word. Words that are forward referenced are automatically defined, and then when really defined, they are automatically resolved. AUTOLOAD.SEQ A simple utility to make F-PC load a file automatically at boot time. Add this to the system and resave the system. Place your forth commands in the file F-PC.CFG and they will be executed before F-PC handles the command line. BLKTOSEQ.SEQ This file contains the source for a utility to convert your .BLK files into .SEQ files. Type the following to convert a file: FLOAD BLKTOSEQ <enter> CONV <enter> <file_to_convert> <enter> You will be prompted for a name of a block file. The .BLK file will be converted to a sequential file, with the new extension .SEQ. All extra blank lines will be omitted. Shadow screens in .BLK files will be enclosed in F-PC's "Comment:" mechanism, and appended to each source block. If a BLOCK file does not have shadows, then change its extension to .SCR, and F-PC will convert all screens sequentially. BLOCK.SEQ A new virtual block system for Forth. This is Tom's own implementation. It is very fast, and uses a true 'Least Recently Used' buffer allocation mechanism. You can also change the block size to be anything you want, as well as specify as many or as few block buffers as you can hold in memory. BOOKMARK.SEQ A Bookmark utility for the F-PC editor, allows saving and restoring 5 different file and line offsets. For example: OPEN F-PC 3 LIST \ Open a file and specify a line. M1 \ Save place with Bookmark # 1 OPEN SEDITOR \ Open the editor 400 LIST \ Specify line 400 M2 \ Save place with Bookmark # 2 BM1 \ Go Back to bookMark # 1 L \ List line 3 of F-PC BM2 \ Go Back to bookMark # 2 L \ List line 400 of SEDITOR M1 to M5 and BM1 to BM5 are valid bookmarks. CARDFILE.SEQ A card contains 1024 characters arranged in 16 lines of 64 characters. CARDFILE uses menus and windows to edit and manipulate cards. Back to blocks! CODEHIGH.SEQ Utility to allow calling high level words from assembly (code) definitions. COMMAND.SEQ A nestable comment line entry routine. Can be placed in a program to allow entering Forth commands without fear of aborting the currently running Forth word. CONSTANT.SEQ A utility to allow defining multiple constants and variables as follows: CONSTANTS 3 george 12 robert 14 betty 72 bongo ; VARIABLES Gort! clatoo borada nicto ; Note the ";" terminating the list of constants. If you use multiple lines, you can put "\" delimited comments on the same line as the constants or variables. DOSIO.SEQ A conversion utility to allow F-PC to accept re-directed input and output from the DOS command line. You can make filters that use all of the power of Forth. EVAL.SEQ A utility to allow run-time interpretation of compiled strings. This implements text macros. EMMEXMPL.SEQ An example of how to use the Expanded Memory Manager. Tests and uses expanded memory to save a bunch of screens and display them on the screen very quickly. EMMHEADS.SEQ After loading EXPANDED.SEQ, you can load this file and save the system to a new file. The new resulting .EXE file will use expanded memory for HEADS, freeing up 64k of normal RAM for other uses. This will mostly be useful if you are trying to write a LARGE application. EXPANDED.SEQ An interface to EMM (Expanded Memory Manager). Most of this file was developed by using the examples right out of the INTEL book. FORWARD.SEQ A neat mechanism to handle forward references, and have them automatically resolved. FUNKEY.SEQ A simple utility to allow the 10 function keys to be assigned to Forth words. Saves some key strokes. HANOI.SEQ A cute demo of a character graphics Towers of Hanoi. LOCALS.SEQ An implementation of local variables for F-PC, places then in a separate stack for flexibility. Four locals are defined, LOCALA through LOCALD. A simple syntax is provided for allocating these variables, and deallocation is automatic at definition end. MONITOR.SEQ An on screen editor, allows you to cursor up and change all the stuff on the screen, then re-enter it by pressing <enter> on a line. NEWCOM.SEQ A utility to allow the easy creation of VERY SMALL .COM files. OBJECT.SEQ Object oriented utility words from Forth Dimensions Volume 10, number 2 by Rick Hoselton. Sightly modified to run on F-PC. SCROLL.SEQ Some simple code utilities to allow scrolling an area of the screen as specified by two pairs of x/y coordinates up or down one line. SEQTOBLK.SEQ This file contains the source for a utility to convert your .SEQ files back to .SCR files. Type the following to convert a file: FLOAD SEQTOBLK <enter> CONV <enter> <file_to_convert> <enter> You will be prompted for a name of the sequential file. The .SEQ file will be converted to a BLOCK file, with the new extension .SCR. Screen 0 will be blank. The first line of each block will be blank, preceded by a "\". The last line of each block will also be blank. The resulting will be an exact multiple of 1024 bytes in length. The resulting file will need to be substantially edited, to move entire definitions onto one screen, as they are likely to be split across screens in the move. WINDEX.SEQ Displays a more or less alphabetized list of Forth words showing vocabulary and file where it was defined. Just type ALLWORDS <enter> to display an index of all forth words. Load PRINT.SEQ and use PFILE <name>, then print the file to disk with PRINT ALLWORDS. WINDOW.SEQ A nice window package for Forth. Much is in assembly, so its very fast. Primarily useful in an application package. Try the demo. WYSE50.SEQ A simple package to allow EMITted Wyse 50 terminal escape codes to be emulated on the IBM screen. This has limited functionality, since only a few of the sequences are implemented. 10.2. FROM CHARLES CURLEY Charles Curley is the F-PC team's devil's advocate. His lean, mean, implementations of real- FORTH run on 6502, 6809, LSI-11, 80X8X and 680XX, both under operating systems and stand alone. Prior to working at Maxtor he worked at or contracted to Rockwell International, Jet Propulsion Lab, Hughes Aircraft, Strand Lighting and other companies. His code has been used to check out the Gallileo spacecraft, write and debug rock shooting games, and light exhibits at world fairs. He sees F-PC as a sneaky plot to sell more Maxtor hard disk drives. DISASSEM.SEQ A 8086 disassembler. This disassembler is patched into SEE, so all you have to do is type: SEE <code_word> <enter> You will see a line of Assembly code. Continuing to press <enter> after each line shows additional instructions. Press ESC to terminate disassembly. You can also disassemble from an address: <addr> DISASSEM <enter> The disassembler displays Postfix notation ala F83. FDIS.SEQ A disassembler for 8087 machine code. Extension of the F-PC disassembler. Bob Smith did it, but the file is grouped here. DIS8086.SEQ Donation from Bill Muench, is a modified version of Curley's DISASSEM.SEQ above, adjusted to disassemble in PREFIX mode. The disassembly can be sent to a file from either of the above files by using PFILE to specify a <printfile>, then typing: PFILE EXIT.SEQ <enter> PRINT SEE EXIT <enter> PCLOSE <enter> to disassemble EXIT to the file EXIT.SEQ. 10.3. FROM BOB SMITH Dr. Robert L. Smith was a member of IEEE Floating Point Standards Committee. He was also a member of the Forth Implementation Team which gave us figForth. He has heavily participated in the Forth Standards Team and the current ANS Forth Standards Committee. Bob is well know for his meticulous coding style and his attention to precision to the last half bit. He generously contributed his 8087 floating point package and a software floating point package to F-PC. COMPLEX.SEQ Some complex number routines, notably, a complex square root algorithm. Requires HFLOAT or SFLOAT and FLT-EXT. DMULDIV.SEQ A 64 bit by 32 bit mixed divide, with a 32 bit quotient and a 32 bit remainder result. Also, a 32 bit by 32 bit multiply, yielding a 64 bit product (all unsigned). Written by Robert L. Smith in 8086 assembly. HFLOAT.SEQ Software support for the 8087 floating point chip. This package was modified from a version by Mark Smiley to support the prefix assembler used in F-PC. SFLOAT.SEQ Software floating point package for those of us who don't have an 8087. It is compatible with the Forth Venders Group floating point standard. Several files are loaded by SFLOAT.SEQ. This IS a COPYRIGHTed package, and may be used for your personal purposes only. You may not sell it as part of any software package without the consent of Robert Smith. This is a software floating point package for use with the F-PC Forth system. It follows most of the recommendations of the FVG (Forth Vendors Group) Standard Floating-Point Extension. The intention is that the functions be as accurate as is reasonable, consistent with speed as the secondary goal. The basic four functions plus square root should be precise to one half a bit in the least significant bit of the representation. The higher functions have intrinsic errors no larger than one bit in the least significant place. The representation uses a 16 bit word for the sign and biased exponent of the floating point number, and 32 bits for the significand (sometimes called the "mantissa"). That means that the intrinsic accuracy is approximately 9 and a half decimal digits. The largest and smallest representable numbers cover roughly the range from 10 to the plus and minus 4000 power, which is far greater than almost anyone would ever need. The representation does NOT include special cases for infinity, unnormalized numbers, and Not-A-Number. The format is definitely NOT the IEEE Floating Point Standard format. The reason is basically one of speed. The functions in this package are approximately 5 (FIVE) times faster than software implementations using the IEEE standard. In spite of that, it does meet the basic requirement of having the basic four functions be accurate to within one-half a bit. The precision is somewhat greater than one would obtain from the 32-bit IEEE format. To load the package from F-PC, type FLOAD SFLOAT followed by a carriage return. After SFLOAT has been loaded, you may enter floating point numbers in exponential format. The following is a list of possible entries: -1.2345E4 .9876E-3 123.456(10) The rules are: If the number is negative, it must be preceded with a minus sign. Do not use "+" with positive numbers. The separator between the mantissa and exponent must be either the letter "E" or a left parenthesis. In the examples above, the "E" is used for compliance with FVG, but the left parenthesis may be used, especially if you desire to enter your numbers in another base. The terminating symbol may be omitted, but you may wish to use a right parenthesis, as in the third example above. The simplest numeric output is E. . Other possible functions are: E.R , F. , and F.R . There is also a floating point stack printout word, .FS . If you wish to turn off the Floating Point interpreter, enter NOFLOATING . To re-enter the floating point interpreter, enter FLOATING . FLOATING POINT GLOSSARY The low level words in the HFLOAT and SFLOAT packages differ significantly because of the hardware facilities. However, the high level application words are very similar, based on the proposed FVG floating point standard. These high level words will be used in applications requiring floating point numbers. It is thus appropriate to summarize this set of high level floating point words common to both HFLOAT and SFLOAT. HFLOAT/SFLOAT GLOSSARY FLOATING POINT STACK WORDS FDUP ( F: r -- r r ) Duplicate the floating point number at the top of the stack. FDROP ( F: r -- ) Drop the top floating point number from the stack. FNIP ( F: r1 r2 -- r1 ) Remove the second floating point number from the stack. Equivalent to FSWAP FDROP . FOVER ( F: r1 r2 -- r1 r2 r1 ) Push a copy of the floating point number second on the stack. FSWAP ( F: r1 r2 -- r2 r1 ) Interchange the top two floating point numbers on the stack. FROT ( F: r1 r2 r3 -- r2 r3 r1 ) Rotate the top three elements on the floating point stack, bringing the third element to the top. F-ROT ( F: r1 r2 r3 -- r3 r1 r2 ) Reverse rotate the top three elements on the floating point stack, putting the top element to the third position. FPICK ( F: rn rn-1 ... r0 -- rn rn-1 ... r0 rn ; n -- ) Using a zero referenced value of n , pick the n-th value from the floating point stack and push it onto the floating point stack. Thus 0 FPICK is equivalent to FDUP . FNSWAP ( F: rn rn-1 ... r0 -- r0 rn-1 ... r1 rn ; n -- ) Exchange the floating point value at the n-th location on the floating point stack with the floating point value at the top of the floating point stack. Thus 1 FNSWAP is equivalent to FSWAP . FLOATING POINT MATH WORDS F- ( F: r1 r2 -- r3 ) Subtract the floating point number at the top of the stack from the floating point number second on the stack. Report overflow errors. F\- ( F: r1 r2 -- r3 ) Reverse subtraction. Subtract the floating point number second on the stack from the floating point number at the top of the stack. Report overflow errors. F+ ( F: r1 r2 -- r3 ) Add the two floating point numbers at the top of the stack. The result is placed back on the stack. Report overflow errors. F* ( F: r1 r2 -- r3 ) Multiply the top two floating point numbers on the stack. Report overflow errors. F/ ( F: r1 r2 -- r3 ) Divide the floating point number second on the stack by the floating point number at the top of the stack. Report overflow errors and division by zero. FSQRT ( F: r1 -- r2 ) Replace the floating point number at the top of the stack with its square root. Report an error if r1 is negative. FMAX ( F: r1 r2 -- r3 ) Replace the top two numbers on the floating point stack with the greater of the two. FMIN ( F: r1 r2 -- r3 ) Replace the top two numbers on the floating point stack with the smaller of the two. FABS ( F: r1 -- r2 ) Replace the floating point number at the top of the floating point stack with its absolute value. FNEGATE ( F: r1 -- r2 ) Negate the floating point number at the top of the floating point stack. 1/F ( F: r1 -- r2 ) Take the reciprocal of the floating point argument. FLOATING POINT LOGIC WORDS F0< ( F: r1 -- ; -- flag ) Test the floating point number at the top of the floating point stack. If the number is less than zero, push a -1 flag on the parameter stack. If the floating point number is greater than or equal to zero, push a 0 flag on the parameter stack. In either case, drop the floating point number from the floating point stack. F0> ( F: r1 -- ; -- flag ) Test the floating point number at the top of the stack, then drop the number. If the number was greater than zero, push a -1 flag on the parameter stack. Otherwise push a zero. F0= ( F: r -- ; -- flag ) Test the floating point number at the top of the stack, then drop it. If the number is zero, push a -1 on the parameter stack. The flag is set to 0 if the floating point number was not zero. F= ( F: r1 r2 -- ; -- flag ) Compare the top two floating point numbers. If the numbers are equal, push a flag of -1 on the parameter stack. If the two numbers are not equal, push a zero. In either case, drop the two numbers from the floating point stack. F< ( F: r1 r2 -- ; -- flag ) Compare the top two floating point numbers. If the number second on the floating point stack is less than the top number, push a flag of -1 onto the parameter stack. Otherwise push a 0 onto the parameter stack. In either case, the top two numbers on the floating point stack are dropped. F> ( F: r1 r2 -- ; -- flag ) Compare the top two floating point numbers. If the number second on the floating point stack is greater than the top number, push a flag of -1 onto the parameter stack. Otherwise push a 0 onto the parameter stack. In either case, the top two numbers on the floating point stack are dropped. TRANSDENTIAL FUNCTIONS FLN ( F: r1 -- r2 ) Natural logarithm function. Time: 1260 usec. FLOG ( F: r1 -- r2 ) Logarithm of base 10. FEXP ( F: r1 -- r2 ) Floating point exponential function e^x FALN ( F: r1 -- r2 ) Alternative name for the exponential function. This is the name specified in the FVG Standard Floating Point Extension. FALOG ( F: r1 -- r2 ) Take the inverse log of r1, i.e., raise 10 to the power of r1. FTAN ( F: r1 -- r2 ) The input is a floating point number in radians. The output is is the tangent of the number. An error condition exists for sufficiently large input values. FSIN ( F: r1 -- r2 ) Returns the sine of the input number in radians. Input and output values are floating point numbers. An error condition exists for sufficiently large input values. FCOS ( F: r1 -- r2 ) Returns the cosine of the floating point argument in radians. An error condition exists for sufficiently large input arguments. FATAN ( F: r1 -- r2 ) Returns a floating point value equal to the arctangent of the input argument. The result is expressed in radians. FASIN ( F: r1 -- r2 ) Returns a floating point value equal to the arcsine of the input argument. The result is expressed in radians. If the input argument exceeds 1.0 in value, an error condition results. FACOS ( F: r1 -- r2 ) Returns a floating point value equal to the arccosine of the input argument. The result is expressed in radians. If the input argument exceeds 1.0 in value, an error condition results. FSINH ( F: r1 -- r2 ) Hyberbolic sin function. Not in HFLOAT. FCOSH ( F: r1 -- r2 ) Hyperbolic cosine function. Not in HFLOAT. FTANH ( F: r1 -- r2 ) Hyperbolic tangent function. Not in HFLOAT. FASINH ( F: r1 -- r2 ) Inverse hyperbolic sin function. Not in HFLOAT. FACOSH ( F: r1 -- r2 ) Inverse hyperbolic cosine function. Not in HFLOAT. FATANH ( F: r1 -- r2 ) Inverse hyperbolic tangent function. Not in HFLOAT. FTRIG0 ( F: r1 -- r2 ) Returns a floating point value equal to the square root of the absolute value of (1.0 - (r1^2)). This is a useful auxiliary function suggested in APL. Not in HFLOAT. FLN2 ( F: -- r1 ) Push a floating point number with a value approximately equal to the natural logarithm of 2. Not in HFLOAT. F**N ( F: r1 -- r2 ; n -- ) Raise the floating point number to the integral power specified by the number on top of the parameter stack. Not in HFLOAT. F/LN2 ( F: r -- r/ln2 ) Divide the floating point number by the natural logarithm of 2. Not in HFLOAT. MISCELLANEOUS WORDS FCONSTANT ( F: -- r ) Create a floating point constant. FVARIABLE ( -- addr ) Create a floating point variable. PI ( F: -- r1 ) Push a floating point number with a value approximately equal to pi. F0.0 ( F: -- r1 ) Push a floating point number with a value equal to 0. F1.0 ( F: -- r1 ) Push a floating point number with a value equal to 1. FINFINITY ( F: -- r1 ) Push the floating point number representing the largest representable number onto the floating point stack. E. ( F: r -- ) Print a floating point number in exponential (power of ten) format .FSINH ( F: r1 -- r2 ) Hyberbolic sin function. Not in HFLOAT. E.R ( F: r -- ; n1 n2 ) Display the floating point number r on the currently selected output device in exponential form with n1 digits to the right of the decimal point, right justified in a field of width n2. Not in HFLOAT. F. ( F: r -- ) Display the floating point number on the currently selected output device in fixed-point form; i.e., the location of the decimal point is adjusted so that no exponent need be displayed. The number of digits to the right of the decimal point specified by the most recent execution of the word PLACES are printed to the right of the decimal point. A trailing blank follows. For example, 4 PLACES 1.2345E02 F. will display as 123.4500b (where the "b" denotes an ASCII blank). If the number of digits to the left of the decimal point is greater than 14, the error routine is called. Not in HFLOAT. F.R ( F: r -- ; n1 n2 ) Display r on the currently selected output device in fixed point form with n1 digits to the right of the decimal place, right justified in a field of width n2. If the number cannot be represented within the given field width, the error routine is called and the value is printed in exponent form. For example, 1.2345e2 4 12 F.R will display as bbbb123.4500 (where each "b" character denotes an ASCII blank). Not in HFLOAT. FLOATS ( -- ) Set the flag FLTS . Allows floating point numbers to be input using imbedded decimal points and optional exponent fields. For example: FLOATS 1.234 -5.4 will produce two floating point numbers. Note, however, that a single precision integer, such as 7 , will remain a single precision integer, and a double number with a terminating decimal point, such as 1234. , will remain a double number. FNUMBER ( F: -- r ; adr -- -1 ) ( adr -- d 1 ) Convert the string at the specified address into a real or integer number, with a flag of -1 or 1, respectively. If the number cannot be converted, print an error message. Not in HFLOAT. F# ( F: -- r ) Convert the string following F# into a floating point number. This includes numbers with or without decimal points. Thus F# 34 yields the equivalent of 34X0 . If SFLOAT is loaded, even if in NOFLOATING mode, F# still converts the following number and pushes it onto the floating point stack. Not in HFLOAT. #? ( number --- d 1 ) ( F: -- r ; number --- -1 ) If possible, convert the following word in the input stream into a number. If the string converts to a floating point number, the flag is set to -1 . If the string converts to an integer, the flag is set to 1. If the string cannot be converted, a standard error message is sent. Not in HFLOAT. FLITERAL ( F: -- r ) Create an in-line literal. F@ ( F: -- r ; addr -- ) Fetch the floating point number at the specified address and push it onto the floating point stack. Drop the address from the parameter stack. F! ( F: r -- ; addr -- ) Store the floating point number at the top of the floating point stack in the area specified by the address at the top of the parameter stack. Drop the address from the parameter stack and drop the top element from the floating point stack. F, ( F: r -- ) Allot space at HERE and store the floating point number. Similar to , . Not in HFLOAT. FLOAT ( F: -- r ; dbl -- ) Convert the double number at the top of the parameter stack to a floating point number which is then pushed onto the floating point stack. As with all double numbers, the location of the decimal point is effectively ignored. FIX ( F: r -- ; -- d ) Convert a floating point number to the nearest signed double integer equivalent, removing the real number from the floating point stack and leaving the double integer result on the Forth parameter stack. When the real number lies exactly halfway between two integers, the result is the nearest EVEN number. Underflow gives a zero result. An error condition results if the resulting number is too large to be represented as an UNSIGNED double number. If more error control is desired, you may create your own version using DINTABS. INT ( F: r -- ; -- d ) Convert a signed floating point number to its truncated double integer value. If the conversion did not succeed, report an error.