VOLUME IV, NUMBER 6 $2.50 INSIDE: TEACHING FORTH I FORTH as a Teaching Language ........... Albert S. Woodhull, Ph.D ........ 5 . Teaching FORTH on a VAX ............... Vernor Vinge ................. 8 FEATURES: Algebraic Expression Evaluation in FORTH ... Michael Stolowitz ............. 14 DEPARTMENTS: Letters ........................................................... 3 Standards Corner ...................... Robert 1. Smith ............... 12 . A Techniques Tutorial; Meta Compiling I ..... Henry Laxen ................. 19 L New Products/Reviews ............................................... 22 . Technotes ......................................................... 25 FIGChapter News .................................................. 29 J 1 4 i I i I I i i TEACHING FORTH : j i L 8080/280 FIG-FORTH for CP/M & CDOS systems FULL-SCREEN EDITOR for DISK & MEMORY $50 saves you keying the FIG FORTH model and many published FIG FORTH screens onto diskette and debugging them. You receive TWO diskettes (see below for formats available). The first disk is readable by Digital Research CP/M or Cromemco CDOS and contains 8080 source I keyed from the published listings of the FORTH INTEREST GROUP (FIG) plus a translated, enhanced version in ZILOG 280 mnemonics. This disk also contains executable FORTH.COM files for Z80 & 8080 processors and a special one for Cromemco 3102 terminals. The 2nd disk contains FORTH readable screens including an extensive FULL-SCREEN EDITOR FOR DISK & MEMORY. This editor is a powerful FORTH software development tool featuring detailed terminal profile descriptions with full cursor function, full and partial LINE-HOLD LINE-REPLACE and LINE- OVERLAY functions plus line insert/delete, character inserVdelete, HEX character display/update and drive-track-sector display. The EDITOR may also be used to VIEW AND MODIFY MEMORY (a feature not available on any other full screen editor we know of.) This disk also has formatted memoryand I/O portdump words and many items published in FORTH DIMENSIONS, including a FORTH TRACE utility, a model data i' base handler, an 8080 ASSEMBLER and a recursive decompiler. The disks are packaged in a ring binder along with acomplete listing of the FULL-SCREEN EDITOR and a copy of the FIG-FORTH INSTALLATION MANUAL (the language model of FIG-FORTH, a complete glossary, memory map, installation instructions and the FIG line editor listing and instructions). This entire work is placed in the public domain in the mannerand spirit of the work upon which it is based. Copies may be distributed when proper notices are included. USA Foreign 0 FIG-FORTH & Full Screen EDITOR package AIR Minimum system requirements: 80x24 video screen w/ cursor addressability 8080 or 280 or compatible cpu CP/M or compatible operating system wl32K or more user RAM Select disk format below, (soft sectored only). ................................... $50 $65 0 8" SSSD for CP/M (Single Side, Single Density) Cromemco CDOS formats, Single Side, S/D Density 0 8" SSSD 0 8" SSDD 0 5%'' SSSD 0 5%" SSDD Cromemco CDOS formats, Double Side, S/D Density 0 8" DSSD 0 8" DSDD 0 5%" DSSD 0 5%" DSDD Other formats are being considered, tell us your needs. 0 Printed 280 Assembly listing w/ xref (Zilog mnemonics) ............................ $15 $18 0 Printed 8080 Assembly listing ..................................................... $15 $18 TOTAL $- - Price includes Dostaqe. No Durchase orders without check. Arizona residents add sales tax. Make check or money order in US Finds on US bank, payable to: Dennis Wilson c/o Aristotelian Logicians 2631 East Pinchot Avenue Phoenix, AZ 85016 (602) 956-7678 FORTH Dimensions 2 Volume d .rc 6 er is flexible and moveable, starting sounds misleading, a FORTH that letters .... above the dictionary (like PAD), and runs as its own operating system does ending just below DOS itself (or wher- not run in some other operating sys- Yes on Operating Systems ever you tell it to end). tem, it replaces it. Similarly it doesn’t In William Graves’ FORTH I1 for need “an entire and separate disk all Dear FIG, the Apple 11, programs are saved to itself.’9-Editor On the subject of operating systems through DOS with the command and FORTH, I must admit that I DWRITE and returned to the buffer More! much prefer Dr. Delwood’s or Mr. with the command DREAD. You com- Dear FIG, Arkley’s approach of using the operat- pile an application with the command After having received volume IV of ing system that you are currently run- LOAD (nothing on the stack), which FORTH Dimensions we would like to ning in, rather than creating an entire LOADS the entire buffer. Alternately, purchase the three previous volumes. new one in FORTH. They are right- you can load directly from the disk This is an excellent publication! operating systems are designed to with the command DLOAD. Standard Richard Beers manipulate files; let them! This solves DOS commands are prefaced with the Alpha Computer Services several problems that have arisen in word DOS: (i.e. DOS CATALOG). Virgin Islands that FORTH would no longer need to What could be simpler? You can insert have an entire and separate disk all to a file into another file, thus allowing itself, nor would it necessarily be cut you to save small files of standard ap- No Point in Fixed Thinking plications (as you now do screens) that off from the wealth of utilities that Dear FIG, have been developed in almost any would be useful in many programs, or There exists a hardware trend which operating system. Why should the user you can DLOAD a file directly from is possibly making the “Philosophy of have to worry about (and remember!) another file (a file can even DLOAD itself!?!). Fixed Point” obsolete. which screens contain which things. I recently purchased from FORTH, Everyone I know has a sequence of These structures do not sully or defile FORTH, or turn it into some- Inc.; Polyforth 2 with 8087 support blocks off somewhere that are set for my IBM PC. Polyforth uses the aside for a listing and description of thing it Was Never Meant To Be. Rather, these file systems are just 8087 register stack as an extra FORTH what is where on this disk. What is the stack. I believe that this efficient use difference between having to list that another example of the tremendous of the 8087 architecture makes 4 block and just typing “DIR” or versatility and extensibility of FORTH an unbeatable number ‘‘CATALOG? ” FORTH. This is already being done to some I think it would not be out of line Continued extent. There are versions of FORTH for the Standards Committee to look that set aside a file under CP/M that into adding words like those above to contains all the screens, thus allowing a future release of FORTH, not as a FORTH to co-exist on a standard replacement to blocks, but as an alter- FORTH Dimensions CP/M disk (though not to interact native. It would make FORTH very Published by FORTH Interest Group with other things on that disk), ver- little less dependent than it now is- Volume IV, No. 6 sions of FORTH that contain screens just as certain words (KEY, EMIT, March/April 1983 for saving and retrieving files under ?TERMINAL, etc.) must change from Editorial the operating system of that particular installation to installation, so to would Leo Brodie machine, etc. these words need to change. Publisher The lack of a block-oriented file is, FORTH will never really gain ac- Roy C. Martens in my opinion, not a big problem. The ceptance in the Real World if you have IISpesetting/Production standard block structure is nice for to tell people they have a choice: they LARC Computing, Inc. many things, but a real pain for can either use FORTH with their hard others. There is no reason that it could disk, or everything else in the world. FORTH Dimensions solicits editorial not co-exist peacefully with the oper- Please keep up the excellent work! material. comments and letters. No re- ating system’s file structure. Then you The only complaint I have is that sponsibility is assumed for accuracy of could use whichever one best suited FORTH Dimensions comes out far material submitted. Unless noted other- wise, material published by the FORTH your needs at the time. Applications too infrequently to suit me! Interest Group is in the public domain. are created as standard DOS files, Nick Francesco Such material may be reproduced with which are read into a buffer area for Rochester, New York credit given to the author and the editing. One of the primary benefits of FORTH Interest Group. this is that you are not limited to an While I personally prefer “native Subscription to FORTH Dimensions is free with membership in the FORTH I artificial 1K range for a definition, so FORTH” directly controlling disk and Interest Group at $15.00 per year you can spread it out as much as you other systems, I agree that running un- ($27.00 foreign air). For membership, like, indenting and commenting to der an operating system can be useful. change of address and/or to submit material, the address is: FORTH Inter- your heart’s content. The resulting I definitely agree to the need for stan- est Group, P.O. Box 1105, San Carlos, readability lays to rest forever the dardization, but this is unlikely to CA 94070. argument that FORTH code is un- come from the Standards Team for a readable to the uninitiated. This buff- good long while. Just to clear up what FORTH Dimensions 3 Volume IV, No. 6 Letters ... (Continued) cruncher. Consider the following ex- who haven’t got those back issues and having seen Mr. Cholmondeley’s work ecution times that I measured. don’t possess a word processor must (IIIM), I repeated a lot of it.