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CNews (1.12) Oct 30,1988 CNews (1.12) *-------------------------------------------------------------* | C NEWS - International C Newsletter, Compiler review, and | | tutorial. | *-------------------------------------------------------------* Table of Contents The Heap: Messages from the Editor ..........................2 by Barry Lynch A Beginner's View of C ......................................4 by Jerry Zeisler Public Domain Software Review/Interview ...................10 by Barry Lynch and Mike Smedley(CXL) Article Submission Standards ................................12 Address's ...................................................13 Distribution Points .........................................14 User Response Form ..........................................15 C News is an electronic journal published by the C BBS in Burke, VA on a monthly basis. The subject for C News is the C programming language, as well as any derivatives like C++. All readers are encouraged to submit articles, reviews, or comments for submission. C News is freely distributed, but can not be sold for a profit, or cannot have a charge assessed to cover distribution costs. To do so is in direct violation of the License agreement. Copies of which are available from the C BBS. This publication is Copyrighted under U.S Copyright Law. -1- CNews (1.12) Oct 30,1988 CNews (1.12) THE HEAP: Messages from the Editor FEEDBACK: Part II In Issue 11, I went out on a limb and risked offending some C News readers, by complaining about the lack of feedback. Well, in the weeks that have passed since, letters and postcards have come in with comments on C News and the articles included within. Two of those letters could not have come at a better time. Every month here in Virginia, we have a "C BBS " Users meeting on the third thursday of the month. This month the meeting was held at Arnie Cherdak's house in Maryland. Before, the meeting I went to my mail box and picked up two letters, one from Phil Loaiza, and the other from Deborah Norling. Both writers took the time to fill out the "User Response Form" that is included with each issue of C News. First, Phil's Letter: what caught my eye, was the following line from Phil's letter. "Please pass along my thanks to Arnie Cherdak on his Database Design article... ask him if he could flesh out B trees a bit more in a future article.." I showed Phil's letter to Arnie, and quite frankly he was thrilled. There is not a whole lot more that is satisfying then receiving praise from one's peers. Arnie now feels refreshed and may consider working on that article that Phil asked for. Deborah also took the time to fill out the response form and had this to say: "...Issue 11's memory models article was the best explanation of how C handles segmentation that I have ever read.." Bill Mayne who authored that article, and was at the user meeting as well appreciated the kind words from Deborah as well. As I mentioned previously, both letters could not have been better timed. THIS ISSUE'S LEAD ARTICLE This issue features an interesting article from Jerry Zeisler, a frequent local user of the C BBS. A few months ago, Jerry and I were talking about a program that he had developed for an application at his company. As Jerry, and I were talking over lunch, I suggested that maybe he write a small article on the creation of "Vcomm". <Jerry's Application>. Well right after Issue 11 was released a draft of his thoughts to me, and we worked out the article that you will read in this issue. This is an interesting look at how a beginner started in C programming. It doesn't get into what books he read, or what editor he used. But it does outline some problems he ran into, how he used a local BBS to help solve them, and what the final outcome was. Jerry's application resulted in his creating an outstanding application for his company, an article for C News on Memory -2- CNews (1.12) Oct 30,1988 CNews (1.12) Models (Issue 10), and the article in this issue. If after reading his article, you think that you might have a similiar story to tell, drop me a line.. POSTCARDS WANTED! I have an idea, I would like to know all of the places on the globe that C News has made an appearance. So, if you have time, send me a postcard from wherever you are, and I will keep a running tally of the states and countries that read C News. It will be interesting to see just what corner's of the globe C News has made it to. I will do you the favor of sending you a postcard from the "Nation's Capitol - Washington, D.C". This sort of reminds me of the Ham radio operators sending their call letters to each other on post cards. SHAREWARE/PUBLIC DOMAIN SOFTWARE AUTHORS In this issue I review briefly, the CXL windowing library package by Mike Smedley. If you are an author of a package, and you would like to see it reviewed in C News, please contact me at one of the address's listed in the back of this issue. This forum will provide you with some free advertising, and it gives me the opportunity to review some of the packages that are available currently. If time is a problem for me then I will ask user's to review the packages. Let's here from you... In closing, thanks for the support and let's help move C News into it's 2nd year of existance! Barry - Editor C News -3- CNews (1.12) Oct 30,1988 CNews (1.12) A BEGINNERS VIEW OF "C" by Jerry Zeisler ABSTRACT: Jerry's own account of his experiences in developing a specialized application for his company's high speed international modems. Jerry reflects on choosing a compiler, tools to use, and some of the problems that he ran into as a beginner. INTRODUCTION As is the way that most projects get started, my company had a need. I work for a large firm that manufactures data communication products, most notably high speed premium modems. Not the mail order type, but the CCITT international community type. When the product was first introduced into this country a while back, it was most notably lacking an easy user interface for dialing and configuration. The modem uses soft straps for configuration which can be accessed via an async terminal. The dialing procedure is via V.25 bis (similar in concept to Hays AT) or manual dialing only. This of course has made the product somewhat difficult to market in the US where the AT command set has become the Defacto standard. But, it seems that since divestiture there has been no single US company or organization with enough power to take the lead in forming strong US standards, so the CCITT standards are becoming more fashionable here in the US, therefore our entry into the US market. So, how does this rags to rags story relate to 'C'? THE IDEA I decided about 8 months ago to design and build a program that will make the V.25 bis protocol totally transparent to the user, hopefully easing our way into the asynchronous marketplace. Being the enterprising fellow that I am, I decided to take the giant step into 'C' in order to program the monster that I had in mind and to finally learn a language that I seen for a long time but never touched. I knew that it wasn't going to be an easy task since I am not a programmer by trade, nor do I do it as a hobby, only as required. I have done some programming previously. Starting about 14 years ago in the Army I maintained a computer system called AUTODIN manufactured by Philco Ford. It used a 32 bit word and the only language available was an assembler. I learned a lot from that experience but didn't do much more until about 3 years ago when I developed a large program using Dbase III Plus. -4- CNews (1.12) Oct 30,1988 CNews (1.12) DECISIONS...DECISIONS I had originally considered using Pascal but heard that it may not be flexible enough for the type of communications programming that I had in mind. So 'C' it was. I had been playing around on BBS's for awhile and just happened to come across the 'C BBS'. It was great timing since I was looking for help from whatever sources I could find. While looking around the C BBS file system I came across some tutorials and downloaded them (C Tutor, etc.). They were exactly what I was looking for, an easy and painless way to learn C. I also 'listened in' on the compiler wars that were going on at the time and decided that the best compiler for my application and experience was Turbo C. The integrated environment that was touted by Borland enticed me more than any other feature. I now consider that decision to be a very good one as I have been completely satisfied with it's operation. I'll get into the nitty gritty about that later. PUTTING IT TOGETHER So what did I want my program to do? How was I going to lay it out? What toolbox's was I going to use (if any)? The way I decided on the look and feel was to see what was currently available in shareware on the BBS as well as how other communication programs operated. This way I could see if I could handle C without risking too much money and at the same time take some of the better ideas from other programs. After sifting through numerous demo programs, I decided that the Window Boss would be the program I would use as the user interface and LiteComm(tm) as the communications toolbox. Once again, for what was available at the time I think that these were good decisions. Again, more on these later. The way I started to build my program was to determine how the V.25 bis protocol in my modems actually worked, since that was the core of the program to be built. The program required downloading or uploading 64 bytes of configuration and dialing data to and from the modem along with the appropriate commands. So the program actually developed from the inside out. I built the V.25 bis engine to communicate with the modem first, testing each command along the way. Then I built the shell around the engine which contained the user interface window program. Of course as with any program, problems existed and persisted. -5- CNews (1.12) Oct 30,1988 CNews (1.12) PROBLEMS AND HEADACHES Problem number 1. What model to use? Small seemed to be appropriate as I didn't feel (and didn't know any better) that the program would be overly large. Also it would take up less disk space. Problem number 2. I needed a line editor for entering either text information or numbers. The editor needed to be flexible enough to include a user defined data feature since the configuration data consists of 1's and 0's only. I found a public domain editor that someone had developed specifically for the Window Boss, but was not well structured and was kind of long. It also had some bugs in it as well as some features that I had to fix and add along the way. It was useful for a while. The biggest problem that I ran into while building the program was what features was I going to put into this thing? Unfortunately I didn't have a really well defined plan prior to starting and it definitely hurt me as the program developed. I guess that the real reason for this is that I didn't know what could be done within my level of experience as well as with the utilities that I was using. So not only were the specifications changing along the way, but as I learned more and more I kept adding and adding and making the program more 'perfect'. Kind of like a catch 22. You don't know what you can do until you do it, and then when you do it you find out that you can do more, so you do more and learn more, and do more... Well, I finally called some of the other marketing people in my company and asked them what would be sufficient for a first release. It sure was a relief when I got a specific stopping point from those people! CONTINUING ON Of course as I added features to the program the effect on functions that were already built without the new features in mind was a real pain and very time consuming. In some cases I had to completely rebuild or kludge the older function. This certainly says something for developing a master plan prior to starting a major task as this. Some things I didn't learn until most of the program was completed, such as function prototyping. None of the material that I had read said anything about function prototyping. The first place that I saw it was in one of the toolbox's that I was using. It still isn't in the program. -6- CNews (1.12) Oct 30,1988 CNews (1.12) SOME MORE HASSLES Well soon enough the source program became very large. It consisted of 5 separate files totaling about 100K! That's a lot of stuff! I had to pare it down somewhat in order for it to be more manageable. The executable was hovering around 60K. Well, there were a few changes that could be done that would downsize the source and allow me to eliminate 2 files. The changes were to upgrade the toolbox's and the compiler. I started out using Turbo C 1.0, Window Boss, Litecomm, a shareware graphics package (HSA) and the separate public domain line editor. It was time to upgrade since TC now had 1.5 and Window Boss and Litecomm both had upgrades. Actually, the upgrades didn't happen all at once but for the sake of a shortened story we'll say that it happened that way. The upgrade to Litecomm happened first. This upgrade was not going to save me anything in size, but it fixed two problem that needed fixing. The upgrade to the Window Boss was next. It allowed me to eliminate the separate line editor since the new version of the Boss included one. It also fixed some annoying problems when exiting the program. The last upgrade was to TC 1.5. This version allowed me to eliminate the shareware graphics package since TC 1.5 has graphics functions. So I went from 5 files down to three. Much more manageable. Of course, throughout the writing of the program were the all night debugging sessions, calls to people on the C BBS, calls to the C BBS sysop (Barry Lynch) at all hours, calls to Phil and Ralph of the Window Boss and Litecomm and of course those sleepless nights tossing and turning due to a bug that I could of sworn was a easy fix. It was a challenge to say the least. HOW DO I KNOW WHEN IT'S TIME TO CHANGE MEMORY MODELS? Well, after the last upgrade the worst (well maybe not THE worst, but pretty much a royal pain) finally happened. "Too much global data defined" said the compiler as I was recompiling. It was time to change memory models. Not so easy. What was interesting about having to change memory models was that a number of weeks prior to this latest disaster I had posted a message on the C BBS asking "how do I know when it's time to change models?." What I got was a lot of stuff that was over my head, although I certainly want to thank all those that tried to educate me and who took the time to answer. It actually had those people thinking out there! It had them thinking so much that Bill Mayne recently wrote a superb article for the C BBS on that exact topic! The only problem was that nobody had the answer that I was looking for. How was I supposed to know when my data or code got too big? How was I supposed to measure it? I got my answer when the compile crashed. -7- CNews (1.12) Oct 30,1988 CNews (1.12) What did I need to get this thing cooking again? Obviously I needed to determine what model to upgrade to. I received suggestions from the people on the C BBS to go to Compact or Medium. Unfortunately they also crashed with the same error (not the people, the compiler). So to Large I went. That was fun (sarcastically speaking). No problem with TC 1.5 but I had made some changes in the source code and header files for Litecomm as well as the Window Boss. The Litecomm change wasn't too difficult but the Window Boss cost me money! It seems that the Large model isn't included but can be compiled with batch files that are included. Unfortunately there is also assembler code that needs to be assembled and linked. Did I have an assembler? Of course not. What did I have to do? Go out and buy one. Ping...$100. So much for inexpensive shareware. I finally got everything compiled and linked. Guess what? Just try to guess the new size of the .EXE file. The one that was last compiled using the Small model was just over 71k. How about 161K! Yeech! Oh well. That's life. Since I had been writing the program for about 6 months (on and off) I learned a few things about C, and so was able to squeeze it down to the slim 160k that it is today in it's Beta test form. TOOLBOX'S Now some words about the toolbox's that I used, The Window Boss from Star Guidance Consulting, Inc. and LiteComm from Information Technology, Ltd. WINDOW BOSS First of all I purchased the source code from both companies. In the warranty for the Window Boss it said that there would be free upgrades for one year. Well, when I needed my upgrade, the upgrade was not free. The answer Phil gave was that it was a major change, not just a minor upgrade. "OK. I'll buy it, but I'm not happy about it." I had no choice since I needed the software and I had about 6 months of my life already invested! I must say in fairness that it really was a major change and made my life a little easier. I had the opportunity to speak to Phil a number of times and was pleased in the most part for the service that he provided. The only complaints are in regards to the upgrade policy and having to purchase an assembler to get my Large model. Phil was rarely immediately available when I called and the person answering the phone was unfamiliar with the software, but Phil always returned my calls within a reasonable period of time. -8- CNews (1.12) Oct 30,1988 CNews (1.12) LITECOMM I have no complaints about the service provided by Ralph from LiteComm. One annoying factor though is that he keeps his telephone answering machine on all of the time. I had the opportunity to call Ralph about 6 times or so and not once did he answer the phone himself, BUT my calls were always returned quickly. Ralph answered my questions professionally and was very pleasant and helpful. WHAT ABOUT THE NEXT TIME? Would I use these toolbox's again for my next program? Now that I know more about the C world I would probably look around some more before making that decision but, I would use these programs and my experiences as a baseline for chasing down other newer toolbox's or reviewing the same ones again along with any new updates. Would I continue to use shareware or would I like to go to a commercial package? Since I have had a good experience with the packages I chose, I would definitely look at the shareware packages first. I like the idea of seeing what I'm getting into and trying it out before I buy. I've been looking in the recent programmers magazines and would love to try some of the software, but at the prices that are being charged and no "try before you buy" policy, it makes it awfully difficult to purchase one of those packages. So what's next? I recently got my hands on a new data compression engine and am considering building a file compression program around it. Yes, I know. I'll make sure that I don't use the term ARC anywhere near the program. Turbo C is a trademark of Borland International. Litecomm is a trademark of Information Technology, Ltd. Other trademarks mentioned are the properties of their respective companies. -9- CNews (1.12) Oct 30,1988 CNews (1.12) Public Domain/Shareware Software Review: Program: CXL - C Programmer's Extended Library Purpose: CXL provides a complete set of windowing and data entry routines for the following compilers: Microsoft, TurboC, Datalight, and Zortech C++. NOTE: The C BBS has not received any compensation for this review. Opinions expressed are those of the author only. EDITOR: I had the opportunity to chat on-line with Mike Smedley - creator of the CXL Library - the other day here at the C BBS. What follows is a "C News Interview of sorts", a first if you will for C News. After Mike's comments, a review of the basic features of CXL will be presented. BARRY: Mike, when did you start on CXL, and why? MIKE: I originally started work on CXL in July 1987. It started out as a collection of several of my favorite functions (both C and assembly). I had just purchased Turbo C 1.0 and started using it for development along with MASM. What I liked about Turbo C was its pseudo-register variables and inline assembly allowing me low-level access to the system. As I was developing my personal applications, if I made a function that could be re-used, I added it to my library. BARRY: After you created the first CXL if you will, did you have plans to create a complete library? MIKE: I eventually started trying to think up functions that I could add to my library. I looked over a few Shareware C function libraries and decided to add pop-up windows to my library. I now had a library complete with simple windowing functions, string functions, equipment detection functions, and a few other miscellaneous functions. I decided to release a Shareware version locally in November 1987 just to see how it would do. BARRY: After releasing CXL as shareware in Nov 87, what was the initial response? MIKE: I eventually realized that to make the product more usable for others, I would have to be able to supply libraries for memory models other than small. Considering the amount of assembly language I was using, this was no small task. With help from the macros from the MIXED.INC file included in MASM 5.0, I was able to provide the additional memory models. -10- CNews (1.12) Oct 30,1988 CNews (1.12) BARRY: At this point you have support for different memory models, what about other compilers: like Microsoft, and Zortech? MIKE: Well, I decided that I needed to support compilers other than Turbo C. Using assembly language, this requires a complex system of macros to provide compatiblity. So, I decided that I should rewrite all of the assembly language functions in C. Upon completion of this, porting CXL to other compilers proved quite simple. BARRY: To sum up, what do you think of CXL? MIKE: CXL has come a long way since its conception. Although CXL competes with many commercial packages costing hundreds of dollars, its registration fee remains low to provide users with quality software and support at low prices. REVIEW: CXL stands for "C Programmer's Extended Library", and currently supports various C compilers for the IBM PC and compatibles. Compilers supported include: Microsoft, Borland, Zortech and Datalight. It contains 170 functions that encompass a windowing system, Lotus Style and Pop-Up/Pull Down Menus, Multi-Field keyboard data entry, EGA 43 and VGA 50 line modes supported, DESQview compatibilty, Microsoft Mouse compatiable functions, equipment detection, printing support and more. The shareware version that is available, only supports the SMALL memory model. Other memory models are available after registering for $25, and the source code is provided. Free updates are available for new versions that are released to registered users. I have tried Mike's package rather extensively. It should be noted that I downloaded CXL from Compuserve, several weeks before Mike logged onto my BBS. It was my idea to have a Question and Answer article for C News. I like the entire CXL package. The documentation is EXCELLENT, and complete. This is key point if you are new to C programming. The routines worked as advertised and I am currently using CXL in one of my applications. I like CXL enough, to have sent in my registration fee for the complete package. The registration fee is very reasonable for what you get. And i believe it is very competitive with commercial packages that are available, and some of the more popular shareware packages like: WindowBoss. CXL is worth a look, the Small memory model will suffice for a good number of applications. Give CXL a look. -11- CNews (1.12) Oct 30,1988 CNews (1.12) ARTICLE SUBMISSION STANDARDS AND ADDRESSES As I have repeatedly stated in this newsletter and previous issues, I would like to see user-submitted articles, reviews or questions. Listed below are the standards that should be followed to make my job easier as an editor. - Articles should be submitted in a ASCII non-formatted file. (Margins 0-65 PLEASE) - If the article include code fragments as examples. Then you can include the entire source file if you like for inclusion with the newsletter. - Book or magazine reviews should follow the same format, that is outlined in this issue. The publisher, author, title, and ISBN number are a must. - Compiler/and or product reviews, should include the version number and manufacture. If possible, reviews should include a sample program with benchmarks. If you have any questions you can contact me at the address's included on the next page. -12- CNews (1.12) Oct 30,1988 CNews (1.12) ADDRESSES The C BBS is located at: C BBS % BCL Limited P.O. Box 9162 McLean VA, 22102 or you can send netmail to: 1:109/713 -13- CNews (1.12) Oct 30,1988 CNews (1.12) DISTRIBUTION POINTS Board Name Number Net/Node Sysop United States C BBS (703) 644-6478 1:109/713 Barry Lynch Burke, VA Jaz C-Scape (904) 724-1377 1:112/1027 Tom Evans Jacksonville, FL Eastern C Board (201) 247-6748 1:107/335 Todd Lehr Exec-PC (414) 964-5160 .. Bob Mahoney Milwaukee, WI TAMIAMI (813) 793-2392 Gerhard Barth Naples, FL Sound of Music (516) 536-8723(2400) Paul Waldinger (516) 536-6819(9600 Hayes V) CANADA Another BBS System (416) 465-7752 1:148/208 Mark Bowman Toronto, Canada EUROPE Fido_N1_1 31-8350-37156 2:500/1 Henk Wevers The Netherlands AUSTRALIA Sentry BBS 02-428-4687 ... Trev Roydhouse (300-2400) Non-Mail Times (300-19,200) Mail Hour (Trailblazer) -14- CNews (1.12) Oct 30,1988 CNews (1.12) USER RESPONSE FORM This form will be included as a regular feature in all future issues of C NEWS. What did you think of the content of this Issue? _____________ _______________________________________________________________ What improvements can you think of that would make C News a better tool for the C Community? _______________________________________________________________ _______________________________________________________________ What is your favorite section or sections? ___________________ _______________________________________________________________ What don't you like about C News? ____________________________ _______________________________________________________________ Additional Comments: _________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ -15- CNews (1.12) Oct 30,1988 CNews (1.12) -16-