=============================================================================== Volume 1 Issue 2 April 1989 ------------------------------------------------------------------------------- _____ _____ ____ ____ ___________ / | / | | | | | | _____ \ / |/ | | | | | | | \__\ / /| /| | | | | | | | / / | / | | | | | | | | / / | / | | | | | | | | ____ / / | / | | | | | | | | |__ \ / / | / | | \ \_______| | | |_________\ \ |___| |/ |___| \____________| |________________\ __ __ ____ ______ _____ ____ | \ || / __ \ --,,-- |,--- //--\\ ||\\ || || || || || \\__ || \\ || || || || |,== ---\\ || \\|| ||__|| || ||___ ___// || \_| \____/ || |____ ___/ The Official Newsletter of: The Motorola Users Group of London =============================================================================== =============================================================================== RainbowFest, This Month! =============================================================================== April 1989 MUG Notes Page 1 Motorola Users Group of London 1989 EXECUTIVE PRESIDENT Stan Bischop 603-195 Berkshire Dr. London N6J 3R7 472-5360 VICE- PRESIDENT Gerry Davis 1053 Frances St. London N5W 2L8 453-8686 SECRETARY Judy Daviau 500 Osgoode Dr. #122 London N6E 2G9 668-7277 TREASURER Sheila Smith 95-305 Briarhill Rd. London N5V 4V8 672-3794 MEMBERSHIP CO-ORDINATOR Judy Daviau 500 Osgoode Dr. #122 London N6E 2G9 668-7277 NEWSLETTER EDITOR Sheila Smith 95-305 Briarhill Rd. London N5V 4V8 672-3794 P.D.LIBRARIAN Diane Gubbels R.R. #1 Mt.Brydges N7G 3H8 264-1648 APPOINTED OFFICERS PUBLIC RELATIONS Gerry Thomas 232 Oakland Ave. London N5V 4H1 659-1374 B.B.S. SYSOP Wayne Morrison 1089 Chippewa Dr. London N5V 2T8 451-7217 NEWSLETTER PUBLISHER Wayne Morrison 1089 Chippewa Dr. London N5V 2T8 451-7217 TECHNICAL ADVISORS Stan Bischop 603-195 Berkshire Dr. London N5V 4V8 472-5360 Gerry Davis 1053 Frances St. London N5W 2L8 453-8686 Wayne Morrison 1089 Chippewa Dr. London N5V 2T8 451-7217 MUG Line B.B.S. 24 Hours Daily 300/1200 Baud N-8-1 451-7216 DISCLAIMER The opinions expressed by the authors are not necessarily those of the Motorola Users Group of London, the editors, or the club members. While we try to make sure that all software and hardware projects in this newsletter have been tested and do work, we will not be responsible for any damage to your own personal equipment resulting from using information contained in this newsletter. COPYRIGHT NOTICE Contents of this newsletter are copyrighted 1989 by the Motorola Users Group of London. Reproduction by any means other than for the personal use of members without prior written consent is forbidden. Other non-profit computer clubs may make use of the enclosed material as long as written acknowledgement is made of the source. MANDATE This newsletter is published by and for the Motorola Users Group of London. This club has no affiliation with the Motorola Corporation. This club is a non-profit organization for anyone that may have an interest in Motorola 68XX and 68XXX based microcomputers and the use and exchange of information about these machines. April 1989 MUG Notes Page 2 Table of Contents Page Item ==== ==== 1.....................List of Officers and Mandate 2 ....................Table of Contents 3.....................General Meeting Minutes (March 14) 4.....................Executive Meeting Minutes (March 20) 6.....................Beginners Disk Basic 7.....................Telecom Comments-A Look at our BBS 8.....................The Other Side of Midnight 10....................Startup-OS-9 Directory Structure 12....................Serial Asynchronous Data Transmission 18....................Optimizing Your System 19....................Goodman's Grumblings-Hayes Modems 21....................Tech Tips-Modem Cables Made Easy 22....................Horoscope Humour (Need a lighter minute?) SPECIAL INTEREST GROUPS The Motorola Users Group of London sponsors two special interest groups (SIG's for short). The beginners SIG meets on Tuesday nights at Wayne Morrison's (1089 Chippewa Dr.) starting at 7:00 P.M. The advanced SIG meets at Judy Daviau's (122-500 Osgoode DR.) on Wednesday nights also starting at 7:00 P.M. Whether you have just started out or you are an experienced hacker, there should be something of interest for you! April 1989 MUG Notes Page 3 General Meeting of The Motorola Users Group March 14, 1989 Secretary's Report This was the first meeting held for MUG and we had a great turn out with many new faces and LOTS of enthusiasm. Stan Bischop got the meeting off the ground at 7:00pm with a review of why we started a new group and what we all expect from MUG and it's members. Wayne Morrison picked up from there by previewing the articles in the newsletter. We had a 20 page issue with 11 articles on every topic from The 1988 Clay Model Report to the salvaging of an old Epson MX 80 printer. Hardware, software, product reviews and personal points of view were covered. It was a great issue and our thanks go out to everyone who worked to put it together. Stan picked up from there again and we had a field day with questions, answers and suggestions on the new club and its workings. We have a very good idea now what the members want and what they are willing to help with. MUG members have decided that what we all want is lots of demo's, help in every field from hardware to programming and the availability of P.D. software. We have 4 volunteers to hold Special Interest Groups, 2 for the OS-9 or Advanced SIG's and 2 for the General or Beginner's SIG's. This should take care of the teaching parts as it was shown that very little absorption of information is possible in the general meetings and much more can be learned on the one to one basis that the SIG's provide. As for demonstrations we will have some great ones lined up for you this year and if there is anything special you would like to see then let someone know! We do have a good variety of software in the library including stuff for the Coco 1, 2 & 3 covering utilities, games, telecommunications, music, programming tutorials, etc. A short break was called at this time for coffee and chatting. The meeting was called to order again by Stan Bischop and the Executive introduced themselves to the new members. Stan took a poll on the level of computer skill of the members and we have about 6-8 beginners. There are about 3-4 super techies and the rest of us fall in the middle at various points. It would appear that we have a very good variety of interests and abilities within our membership. It was announced that Diane would have disks available for $1.00 at the meetings for anyone who wants their newsletter on disk but forgot to bring their own. Wayne demonstrated how to get your newsletter printed from the buffer of a terminal package, (Mikey-Term) and Lawrence followed that up with a good review of the NeXT computer. The meeting was adjourned at 8:45 and quite a few of the members met again at The Medallion Restaurant on Dundas St. for coffee and chit chat. All in all it was a teriffic first meeting and we hope to have many more that are just as good! April 1989 MUG Notes Page 4 Motorola Users Group Executive Meeting March 20, 1989 Secretary's Report The meeting was held at the home of the Treasurer, Sheila Smith and was called to order by Stan Bischop at 8:00pm. Those present were: Stan Bischop - President Gerry Davis - Vice President Sheila Smith - Treasurer Judy Daviau - Secretary Wayne Morrison - Electronic System's Manager Diane Gubbels - Disk Librarian Items discussed were: 1) It was announced at our general meeting, March 14, 1989 that the Executive would organize the topics of the upcoming meetings for the whole year and coincide them with the topics covered in the Rainbow Magazine. This has been put on hold until after Rainbowfest as Rainbow Magazine has changed the order they normally use for their magazine. April would normally be Home Help month but they did that issue in February this year. We hope to talk to Lonnie Falk, owner and publisher of Rainbow Magazine, in Chicago and find out what the format for topics for this year will be. 2) It was decided that April's general meeting will be a beginners night and Stan Bischop will start the evening by showing the insides of a Coco 3 and discussing the hardware inside the machine and explaining how it processes information (Data Flow). Gerry Davis will take the second half of the meeting to discuss computer technology and computer terms. If there is a computer related word that you don't understand then this is the time to ask. 3) The seating arrangements of the room was discussed and it was decided to have the Executive tables set up at the back of the room instead of the front. It is hoped that this will enable everyone in the room to see the monitor and that any business going on at the Executive's desks will not interfere with the progress of the meeting. 4) It is urged by members of the Executive that there be as few unnecessary disruptions as possible during the demonstrations at the meetings and that members will be considerate of others in the room. If you must stand up frequently then please choose a seat at the rear of the room or a seat next to the edge. We also have some youngsters who are very interested in the meetings and they have difficulty seeing over the heads of the adults. Where appropriate, please let them have the seats to the front of the room. Everyone is urged to continue asking questions at an appropriate time during the demonstrations. 5) It was decided that Diane, our Disk Librarian, would only bring to the meeting ONE copy of each Public Domain disk in the library and anyone wishing to purchase a P.D. disk should do so between 6:30 and 7:00 P.M. During this time Diane will be able to make you a copy of the P.D. disk you wish to purchase. Diane is the ONLY person who will be allowed to make ANY copies of disks during the meeting and she will make copies of ONLY Public Domain disks in our library. Diane will have on hand multiple copies of the disk/s being used for the evenings demonstrations. 6) It was brought to the attention of the Executive that Diane still owns the disks that our library is stored on. It will be voted on by the attending membership at the April 11, 1989 general meeting whether to pay her for these disks now or at a later date. The amount owed to Diane by MUG is 150 diskettes or the cost of the same. April 1989 MUG Notes Page 5 7) It was decided to purchase 3 boxes of disks to be used as a float for the club. Two of these boxes will go to Diane for use by the library and the other one will go to Wayne. It will enable us to always have on hand disks available to swap for the newsletter, etc. Sheila will purchase these disks this week. 8) Deadline for the submission of articles to the newsletter was set at 3 Saturday's before the general meeting. This will enable Sheila to properly do her job and Wayne to get the newsletter available to the members before the general meeting. 9) It is asked that anyone who is submitting articles for the newsletter should not do any justification to the document as it is impossible to remove it before formating the document for the newsletter. Your co-operation is appreciated. 10) It was decided against the club members testing the P.D. for errors as it would mean fragmenting the library. Gerry Davis will check the programs for errors as he previews them for the demonstrations. Anyone who is having trouble with a P.D. disk program should write down the problem and give it to Gerry Davis at a meeting or put a message on the BBS. 11) Anyone who is accessing the BBS at 300 baud and needs more time to get the newsletter should leave E-Mail to Wayne. He will upgrade your access time to 90 minutes. 12) It was decided that back issues of the newsletter will be put in the P.D. library as we fill a disk. It is estimated that each disk will hold three issues of the newsletter and it will be made available quarterly. 13) Stan has agreed to continue to donate his RDS downloads to the P.D. library. The meeting was adjourned at 10:00pm. SIG GROUPS EVERY TUESDAY NIGHT AT WAYNE MORRISON'S HOUSE (451-7217) EXCEPT MEETING WEEK EVERY WEDNESDAY NIGHT AT JUDY DAVIAU'S HOUSE (668-7277) EXCEPT MEETING WEEK THIS IS FOR THE MONTH OF APRIL EVERYONE IS WELCOME AND THE MORE THE MERRY. PLEASE COME AND JOIN US!!!!!! April 1989 MUG Notes Page 6 BEGINNERS DISK BASIC The first step in beginners is to format your disk. To do this you type DSKINIO and then press your enter button. If you have a second drive type DSKINI1, then press your enter button. The next step in typing a program onto your disk and saving it. example: 10 Print "Store me in a disk file" Now lets take and understand what this does. First 10 = the line in which you are typing. Print = you want this to be printed on your screen or to your printer. " " = what you want printed to the screen or printer. Now after this line you must press to store this line to the program. The next line reads 20 Print "and you'll never lose me" Now you noticed that we use 20 instead of 11 this is done so that you may insert more line between 10 and 20 for error that no one makes.. Now you want to save this to your disk in drive 0 we can type SAVE "SIMPLE.PRO" . Now lets look at what we have asked the computer to do. SAVE = save to your disk drive. " " = what goes into here is the filename which can be 8 letters or number (no periods or anything like that. The extension must be three letter. Now there are certain things used that will help you know what you have save such as like if you used txt which stands for text file, pic could be used for a picture file, gam could be used for a game file. Try to use three letters that we tell you something about the program that you have type. Lets say you want to see what this program does you then type"run" . The computer will display Store me in a disk file and you'll never lose me. You can also type "list" and the program will appear on your screen as you first typed it. Now to clear your screen type "New" . This will clear your computer of any program that you have type in there. If you now type RUN OR LIST you should not have anything on your screen. You may want now to see the program you have stored to disk. You then type LOAD "SIMPLE.PRO" and your program in now back in memory of your computer. If you type RUN OR LIST your program will now appear as above on your screen. This is your first lesson in beginners disk basic. If you need help ask or go to your beginners disk basic manual that comes with your computer. By Sheila Smith WELCOME I would as this time like to welcome all beginners to the Mug group, we are here to help you as much as we can and we direct you to someone to help you if we can not do so. Please feel free to ask as many questions as possible. Remember we all started as beginners and we all asked to simple problem question too. Do not feel that they are not stupid or dumb to ask. You can only get answers if you ask and learning comes with asking. REMEMBER WE ARE HERE TO HELP ALL AND ARE MORE THAN WILLING TO DO SO. Thank you Sheila Smith April 1989 MUG Notes Page 7 Telecom Comments By W. Morrison With the influx of new members that our club has enjoyed recently, I think it pertinent to spend some time reviewing some of the features of our BBS system. Both this month's and next month's columns will be devoted to that task, and I would ask all you "old pros" out there to please bear with me. Remember, we were once new at this too! The logical place to start would be with the main menu. Here, most of the major system decisions are made. You can go to the essage area, check on ther BBS phone numbers in the London area, check the userog to see who has used the system, access downloads and post uploads in the iles area, and set several of the parameters that one normally uses on a BBS system, such as turning on or off carriage returns, turning on or off the uppercase only facility and turning off or on the screen clear command. These last three affect how you see the system on your terminal. Screen clear blanks out the monitor screen at certain strategic places. If you do not like this hit the proper key at the main menu and it will be suppressed. To re-enable it just hit the key again at the main menu. Likewise carriage returns at the end of a line of text can be turned off and on at your desire as can the uppercase only feature. If you have a CoCo 1 or 2 this is especially significant as, depending on your terminal software, this feature allows you to eliminate the checkerboard effect. If you are like most people, you will spend most of your on-line time in the message area. I will now spend some time explaining how to use this area properly and detail what the various commands at the numerous menus can do for you. When you enter the message area, the first menu lists the message areas that are currently available on the system. Once you have made a choice of which area you want to go to, this menu is replaced with another. This one gives you choices to read, scan, enter, combined read, and delete. The read choice is quite obvious but some of the others are not. Scan, for example, allows you to scan all available messages by the message heading (to:,from:.subject:, and date). If you are looking for something specific, this is a quick way to find what you are after, and once found, you can arrange to read that message at the next menu. The delete command allows you to delete messages, but only ones that were either written by you or to you. No one is allowed to delete other people's messages. Combined read allows you to read messages from ALL areas at once. This is handy if there are a lot of new messages and you don't want to have to search all message bases. Finally, the enter command allows you to post a message to the base that you are currently in. For most of these choices except enter, after you have made your choice, another menu asks you if you want Forward, Reverse, Individual, or New. These choices refer to the manner in which the messages will be displayed to you. Forward refers to listing them in a forward numerical order, reverse refers to doing it backwards, and so on. The one interesting point is the New option. This system is able to keep track of the last message that each user has read, and if you select the New option, you will just see the messages that have been posted since your last visit. This is an extremely handy option! That is it for this month, and next time I will go into the mechanics of writing messages and also explore the iles section and how it is used. April 1989 MUG Notes Page 8 The Other Side of MidNight A Guided Tour of the MidNight Remote Data System First in a series of MidNight Madness Reports by Gerry Thomas Welcome to the world of Computer Inter-Communications. If you have a modem, then you have probably already experienced the wonderful world of C.I.C., but for those of you who have yet to add one of these amazing devices to your computer systems, these articles may still be of interest to you, and may provide the impetus to get involved in tele-communications. The Motorola Users Group has and maintains an electronic bulletin board system, (known as a BBS), for the members of the club with modems. There you can find the latest edition of the newsletter, exchange messages, obtain Public Domain programs and many more features that Wayne Morrison (SysOp) will be telling you about. The purpose of these articles, however, is to tell you about another BBS that is NOT operated by the Motorola Users Group, but it IS affiliated. While the "MUG LINE BBS" operated by the club is a BBS, the MidNight Remote Data System is NOT a BBS. That's right ... it is NOT a BBS. But, you say, when I log on to MidNight RDS, everything I see LOOKS like a regular BBS, so why do you tell me it ISN'T a BBS - what gives ?? First of all, most BBS systems use one computer to run the BBS. The SysOp (System Operator) usually has a second computer to do whatever a computer hobbyist does with their computer. The BBS uses the one computer exclusively and that is all that computer does. The "MUG LINE BBS" follows that standard. MidNight Remote Data Systems, on the other hand, utilizes the OS-9 multi-tasking environment, and allows the System Operator full use of his/her computer while a caller is accessing the Data System. Because of the OS-9 environment, which is a Multi-Tasking (can run more than one process at the same time) Multi-User (has a security access system built in) Operating System, the system becomes more then just a BBS. So, although it LOOKS like a BBS to the normal user, it is in fact a REMOTE TERMINAL. More about that in a future report. For now, I will describe the system on a BBS level, but first ..... Before you can go "on-line" (the term used to refer to the act of actually accessing an Information Service Provider [ISP] -(the proper term for a bulletin board system or other similar service) we must consider a few things - Terminal packages, Modems and Monitors. There are several very good terminal packages available for the CoCo but the Public Domain "Ultimaterm 4.1" is recommended for those of you wishing to use an RSDOS based terminal, as it supports the ANSI graphics mode. ( ANSI, which is the acronym of the American National Standards Institute, is the term used in these articles as the standard used to produce multi coloured text on MidNight). Most OS-9 based terminal packages have ANSI and OS9 graphic capabilities, so no recommendation is made as they are all very good.If you set your options to reflect ANSI as active, then the menus take on a colourful appearance. April 1989 MUG Notes Page 9 There are many good Modem ( MODulator-DEModulator) units available for tele-communicating, so specific recommendations are not made, but some pointers are in order. At the low cost end of the scale are the 300 baud units, and they are a good choice for those not sure if they want to spend a lot of money. The "300 baud" refers to the rate of transfer between machines and is about 400 words per minute - adequate for reading text files while on-line. These units are very inexpensive, somewhere in the range of $ 40 to $ 100. The next step up is the "1200 baud" units (good for about 1600 words per minute) and cost about $ 100 and up. Hayes is a modem company that established a 'standard' many years ago and is considered the 'role model' of modems. Most modems, however have followed the Hayes standard, and refer to themselves as being "Hayes Compatible". Because these modems are usually a lot less expensive than a comparable Hayes, a clone is recommended. For reasons that will become evident later on, it is recommended that you use a "1200 baud" modem with MidNight Remote, although a "300 baud" unit will work. Also, since MidNight uses a full 80 column screen on most of its menus, a monitor capable of a clear 80 column display is very highly recommended. A black and white television might work in a pinch, but the menus may be hard to read at times. Of course, an RGB monitor like the CM-8 or similar unit will also allow you to see the menus in colour - a nice touch. The next step is to actually set up your computer to start accessing all those wonderful Information Service Providers. For information on this stage please consult with one of the very knowledgeable technical advisors available to you in the Motorola Users Group. All of them are experienced "Modem Maniacs" and will be very happy to assist you, and get you "up and running". When ready, dial the MidNight number for this sign-on message: MidNight - OS9 Login Pkg (c) 1988 by StG Computers Inc. V2.2 #3CB3443DB3 MidNight Remote -=- xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx -=- MidNight Remote + + + MidNight Remote Data Systems (519) 451-4769 300/1200 Baud 24 Hrs + + + + *** P.O. Box 905, London, Ontario *** + + + MidNight Remote -=- xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx -=- MidNight Remote *** New Users, Please Type 'GUEST' at UserName Prompt *** UserName: At this point, if you are a new user, you would type 'guest' and press and the system will take you to an area where you can get more information on MidNight, and take your application for access. For security reasons, a 'guest' has very limited access to the system. Your application will need to be verified (usually within 24 hours) before you can gain greater access. Registered users of MidNight, will enter either their 'UserName', or their Real Full Name, as recorded in their application file. Next time I will describe what happens to a 'guest' and a 'registered user' from this point. April 1989 MUG Notes Page 10 SSSSSS TTTTTTT AAAA RRRRR TTTTTTT U U PPPPPP S T A A R R T U U P P SSSSSS T AAAAAA RRRRR T U U PPPPPP S T A A R R T U U P SSSSSS T A A R R T UUUUUU P By: J. Daviau Hi everyone. Last month I wrote a bit about what an operating system is and some of what they can do for you. This month I'm going to try to explain a little about the directory structure of OS-9. OS-9 has a really great way of storing files on disk. If you think of an OS-9 disk as a filing cabinet you will be able to understand it easier. When you look at a filing cabinet you see many drawers labeled A-C, D-E, F-I, J-M, etc. If you were to open the drawer labeled A-C you would expect to find some files inside whose names start with the letters A, B or C. Now imagine that these drawers were labeled House, Car, Work, Bank, Clothing, etc. You would expect to find things relating to a car if you were to open the drawer labeled Car. Receipts for purchasing and dry cleaning clothing should be in the one marked Clothing, etc. OS-9 uses the same principle to label things. When you use the directory command to look at an OS-9 disk you will see some labels too. It will look something like this: OS9:dir Directory of . 15:17:22 OS9Boot CMDS SYS startup window.t38s window.t80s window.glr4 What you see above is a list of the labels that are on this disk. As with anything else dealing with computers it is not quite that simple! In the above list only SOME of those labels are drawers. These drawers are called DIRECTORIES. The other labels that are not directories (drawers) are called FILENAMES. They are no different than the filenames that you see when you use the DIR command to see what you have on a Disk Basic Disk. It is standard practice in OS-9 to ALWAYS USE ALL UPPERCASE when naming directories. Following that rule only the ones labeled CMDS and SYS are directories as the other labels have some lowercase letters in the names. So if CMDS and SYS are indeed directories then you should be able to open the drawer and look in there. To do this you use the DIR command again but you have to tell it what directory (or drawer) you want to open. (Do not type the characters "OS9:" This is called an OS-9 Prompt.) This is what you will see: OS9:dir cmds Directory of /d0/cmds 15:25:10 attr backup build cmp cobbler copy date dcheck deiniz del deldir dir display dsave echo edit error format free grfdrv help ident iniz link list load makdir mdir merge mfree modpatch montype os9gen procs pwd pxd rename setime shell tmode tuneport wcreate unlink xmode April 1989 MUG Notes Page 11 So you can see that there are a lot of filenames in that directory. We know that they are filenames and not directories because they all have lowercase letters. (It is quite possible to have another directory in the directory called CMDS or in any other directory also). The abreviation "CMDS" is short for COMMANDS and as you can see all the files in that directory are commands. Let's look in the directory called SYS: OS9:dir sys Directory of /d0/sys 16:13:22 errmsg helpmsg LogBook stdfonts stdpats_2 stdpats_4 stdpats_16 stdptrs All the labels here are filenames too and there are no directories. These files are all related to System Operation. The one called "errmsg" is a list of error messages for OS-9, the file called "helpmsg" is another list of error messages for Basic09, etc. So by using OS-9 it is very easy to keep things right where you can easily find them. All the commands that you can use are in a commands directory, all the system files are in a system directory, etc. Imagine what a mess you would have if all the names were in one spot. Lets try to use the DIR command on a filename and see what happens. OS9:dir startup ERROR 214 OS-9 is telling you that you have encountered an error. To find out what "ERROR 214" means you would type: error 214 at the OS-9 prompt. Eg: OS9:error 214 214 - No Permission This means that you have no permission to use the DIR command on that filename because it is not a directory. Whenever you get an error message you can ask to see the definition of that error number by typing the word error and the number. When we did a DIR the first time it looked like this: OS9:dir Directory of /d0 16:58:11 OS9Boot CMDS SYS startup window.t38s window.t80s window.glr4 This is known as the ROOT Directory. It is called this because it is the beginning point or the root of the disk. This directory is not in another directory. The directory called CMDS is in another directory: the ROOT directory. And the same for SYS. Therefore these two directories are called SUB-DIRECTORIES. The ROOT directory is said to be the PARENT DIRECTORY of these two directories and CMDS and SYS are said to be the CHILD DIRECTORIES. If you were to put another directory inside of CMDS then CMDS would then become a parent directory too, etc. It is not necessary to know a lot of the information in the above paragraph but if you decide to get involved with OS-9 in any detail you will eventually come across references to these terms. If there are any questions or suggestions for this column then leave me some mail on the BBS or see me at the meeting. April 1989 MUG Notes Page 12 Serial, Asynchronous Data Transmission In serial transmission, information is transferred, one data bit at a time, between two computing devices. The flow of this data can follow one of three transmission modes: simplex, half-duplex or full-duplex. Simplex allows data flow in only one di rection; half-duplex allows data flow in both directions (but not simultaneously); while full duplex allows simultaneous two-way transmission. --------------- Data Flow --------------- | Transmitter |-------------------->| Receiver | | | | | --------------- --------------- Simplex Configuration --------------- Data Flow --------------- | Transmitter |<------------------->| Receiver | | & Receiver | |& Transmitter| --------------- --------------- Half-Duplex Configuration --------------- Data Flow --------------- | Transmitter |-------------------->| Receiver | | |<--------------------| | --------------- --------------- Full-Duplex configuration ASYNCHRONOUS DATA FRAME Within the asynchronous data stream, each character of data is transported in a binary bit frame. Each frame begins with a start bit. A low-voltage signal on the data line marks the beginning of the start bit, and the receiving device can then begin looking for 0's and 1's. The following five to eight data bits (the number depends on the code used) comprise the binary character. For error detection, an optional parity bit can mark whether the total of 0's or 1's was even or odd. A stop bit signals the end of the character. (Stop bits range in length from one to two bits. The slower the speed of transmission, the more stop bits required for end-of-frame recognition.) 0 1 2 3 4 5 6 7 8 9 10 | | | | | | | | | | | Logical | | | | State | | | | | | | | 1---| | | | | | | | | | | | | | | |<---------5, 6, 7 or 8 data bits----------->| | | | | | | | | | | | | 0---| Parity bit|Stop bits: | -none/off |1,1.5 Start -Mark |or | Bit -Space |2 usually 1 -Even |Logical Logical 0 -Odd |1 |<-------Asynchronous Word Length---------------->| April 1989 MUG Notes Page 13 Parity bits trap errors in the following manner: when the transmitting device frames a character, it tallies the number of 0's or 1's within the frame and attaches a parity bit. (The parity bit will vary according to whether the total is even or odd. ) Then, the receiving end will count the 0's or 1's and compare the total to the "odd" or "even" recorded on the parity bit. If the receiving end finds a discrepancy, it can flag the data and request a retransmission. Parity selections other than odd and even include mark, space and off. Mark always sets parity at 1; space sets parity at 0; and off tells the system to ignore the parity bit. Parity Description Type ODD Eighth data bit is logical zero if total number of logical 1's in first seven data bits is odd. EVEN Eighth data bit is logical zero if total number of logical 1's in first seven data bits is even. MARK Eighth data bit always logical 1 (high mark). SPACE Eighth data bit always logical 0 (low space). NONE/OFF Eighth data bit ignored. ASYNCHRONOUS LINK CONTROL We have defined the asynchronous frame and the directional modes, but we haven't covered the rules for orderly transmission. Each end of the link has to conform to certain operating parameters in order for flow to occur without loss of data. The first parameter is the rate of transmission. Serial data transmission is measured in bits per second (bps). Typical asynchronous serial baud rates are 110, 300, 600, 1200, 2400, 4800, 9600 and 19,200 bps. In order for two computing devices to interact, both must be operating (transmitting or receiving data) at the same baud rate, or there must be an intermediate memory device, called a buffer, that accommodates the differences in speed. In addition to transmit and receive buffers, most serial asynchronous links use a flow control system to handle data transmission. A common asynchronous serial flow control is X-ON/X-OFF. When a receive buffer reaches its memory capacity, the receiving device sends an ASCII DC3 (X-OFF) signal to the transmitting device telling it to stop sending data. When the receive buffer has sufficiently unloaded, it transmits an ASCII DC1 (X-on) signal back to the transmitting device, telling it to continue transmission. Other flow controls commonly used in asynchronous communications are lead control and the ENQ/ACK protocol. A lead control protocol controls data flow by alternately raising and lowering the voltage on a lead of the RS-232 interface. DTR (pin 20) and CTS (pin 5) are often used. When a pin's voltage is high, data flow is enabled; when it drops low, data flow is stopped. ENQ/ACK is a block-oriented protocol, i.e. a protocol that sends a fixed amount of characters every time it transmits. Typically, the transmitting device sends an ENQ character and waits for an ACK character from the receiving device before beginning transmission. Once the ACK character is received, the entire block is transmitted. When the block transmission is complete, the transmitting device once again begins polling the receiving device with ENQs. April 1989 MUG Notes Page 14 RS-232 Interfaces The definition that I could dig up is: RS-232 is an Electronic Industries Association (EIA) standard, applicable to the 25-pin interconnection of Data Terminal Equipment (DTE) and Data Communication Equipment (DCE) employing serial binary data interchange. Pinout Table for EIA RS-232 25 EIA-RS-232C PIN CIRCUIT USED NAME DESCRIPTION 1 AA Protective Ground 2 BA Y TD Transmitted Data 3 BB Y RD Received Data 4 CA Y RTS Request To Send 5 CB Y CTS Clear To Send 6 CC Y DSR Data Set Ready 7 AB Y GND Signal Ground/Common Return 8 CF Y CD Received Line Signal Detector 9 -- Reserved for data set testing 10 -- Reserved for data set testing 11 == Undefined 12 SCF Secondary Received Line Signal Detector 13 SCB Secondary Clear To Send 14 SBA Secondary Transmitted Data 15 DB Transmitter Signal Element Timing (DCE) 16 SBB Secondary Received Data 17 DD Receiver Signal Element Timing (DCE) 18 == Undefined 19 SCA Secondary Request To Send 20 CD Y DTR Data Terminal Ready 21 CG Signal Quality Detector 22 CE RI Ring Indicator 23 CH Data Signal Rate Selector (DTE) 23 CI Data Signal Rate Selector (DCE) 24 DA Transmitter Signal Element Timing (DTE) 25 == Undefined DB25 references the (25-pin) connector that is commonly used for RS-232. Pins 9 and 10 are reserved for data set testing. Pins 11, 18 and 25 are undefined. Lead 23 of the RS-232 connector may be defined as CH or CI. Before you have a fit, or get on the case of your cable supplier, not all of the above connections are needed for serial communications. At work I run 9600 and 19,200 baud using only pins 2 (TD), 3 (RD) and 7 (GND). I have identified the most commonly used lines. April 1989 MUG Notes Page 15 The following chart makes a very handy reference item. If you are into heavy duty programming, sending codes to your printer, telecommunications or what-ever, it allows you to cross-reference between Decimal, ASCII, Binary, Octal and Control characters. 49 1 31 0011 0001 061 DEC ASCII HEX BINARY OCT CTL 50 2 32 0011 0010 062 0 NUL 00 0000 0000 000 @ 51 3 33 0011 0011 063 1 SOH 01 0000 0001 001 A 52 4 34 0011 0100 064 2 STX 02 0000 0010 002 B 53 5 35 0011 0101 065 3 ETX 03 0000 0011 003 C 54 6 36 0011 0110 066 4 EOT 04 0000 0100 004 D 55 7 37 0011 0111 067 5 ENQ 05 0000 0101 005 E 56 8 38 0011 1000 070 6 ACK 06 0000 0110 006 F 57 9 39 0011 1001 071 7 BEL 07 0000 0111 007 G 58 : 3A 0011 1010 072 8 BS 08 0000 1000 010 H 59 ; 3B 0011 1011 073 9 HT 09 0000 1001 011 I 60 < 3C 0011 1100 074 10 LF 0A 0000 1010 012 J 61 = 3D 0011 1101 075 11 VT 0B 0000 1011 013 K 62 > 3E 0011 1110 076 12 FF 0C 0000 1100 014 L 63 ? 3F 0011 1111 077 13 CR 0D 0000 1101 015 M 64 @ 40 0100 0000 100 14 SO 0E 0000 1110 016 N 65 A 41 0100 0001 101 15 SI 0F 0000 1111 017 O 66 B 42 0100 0010 102 16 DLE 10 0001 0000 020 P 67 C 43 0100 0011 103 17 DC1 11 0001 0001 021 Q 68 D 44 0100 0100 104 18 DC2 12 0001 0010 022 R 69 E 45 0100 0101 105 19 DC3 13 0001 0011 023 S 70 F 46 0100 0110 106 20 DC4 14 0001 0100 024 T 71 G 47 0100 0111 107 21 NAK 15 0001 0101 025 U 72 H 48 0100 1000 110 22 SYN 16 0001 0110 026 V 73 I 49 0100 1001 111 23 ETB 17 0001 0111 027 W 74 J 4A 0100 1010 112 24 CAN 18 0001 1000 030 X 75 K 4B 0100 1011 113 25 EM 19 0001 1001 031 Y 76 L 4C 0100 1100 114 26 SUB 1A 0001 1010 032 Z 77 M 4D 0100 1101 115 27 ESC 1B 0001 1011 033 78 N 4E 0100 1110 116 28 FS 1C 0001 1100 034 79 O 4F 0100 1111 117 29 GS 1D 0001 1101 035 80 P 50 0101 0000 120 30 RS 1E 0001 1110 036 81 Q 51 0101 0001 121 31 US 1F 0001 1111 037 82 R 52 0101 0010 122 32 SP 20 0010 0000 040 83 S 53 0101 0011 123 33 ! 21 0010 0001 041 84 T 54 0101 0100 124 34 " 22 0010 0010 042 85 U 55 0101 0101 125 35 23 0010 0011 043 86 V 56 0101 0110 126 36 $ 24 0010 0100 044 87 W 57 0101 0111 127 37 1 25 0010 0101 045 88 X 58 0101 1000 130 38 & 26 0010 0110 046 89 Y 59 0101 1001 131 39 ' 27 0010 0111 047 90 Z 5A 0101 1010 132 40 ( 28 0010 1000 050 91 [ 5B 0101 1011 133 41 ) 29 0010 1001 051 92 5C 0101 1100 134 42 * 2A 0010 1010 052 93 ] 5D 0101 1101 135 43 + 2B 0010 1011 053 94 ^ 5E 0101 1110 136 44 , 2C 0010 1100 054 95 _ 5F 0101 1111 137 45 - 2D 0010 1101 055 96 ` 60 0110 0000 140 46 . 2E 0010 1110 056 97 a 61 0110 0001 141 47 / 2F 0010 1111 057 98 b 62 0110 0010 142 48 0 30 0011 0000 060 99 c 63 0110 0011 143 April 1989 MUG Notes Page 16 100 d 64 0110 0100 144 151 97 1001 0111 227 101 e 65 0110 0101 145 152 98 1001 1000 230 102 f 66 0110 0110 146 153 99 1001 1001 231 103 g 67 0110 0111 147 154 9A 1001 1010 232 104 h 68 0110 1000 150 155 9B 1001 1011 233 105 i 69 0110 1001 151 156 9C 1001 1100 234 106 j 6A 0110 1010 152 157 9D 1001 1101 235 107 k 6B 0110 1011 153 158 9E 1001 1110 236 108 l 6C 0110 1100 154 159 9F 1001 1111 237 109 m 6D 0110 1101 155 160 A0 1010 0000 240 110 n 6E 0110 1110 156 161 A1 1010 0001 241 111 o 6F 0110 1111 157 162 A2 1010 0010 242 112 p 70 0111 0000 160 163 A3 1010 0011 243 113 q 71 0111 0001 161 164 A4 1010 0100 244 114 r 72 0111 0010 162 165 A5 1010 0101 245 115 s 73 0111 0011 163 166 A6 1010 0110 246 116 t 74 0111 0100 164 167 A7 1010 0111 247 117 u 75 0111 0101 165 168 A8 1010 1000 250 118 v 76 0111 0110 166 169 A9 1010 1001 251 119 w 77 0111 0111 167 170 AA 1010 1010 252 120 x 78 0111 1000 170 171 AB 1010 1011 253 121 y 79 0111 1001 171 172 AC 1010 1100 254 122 z 7A 0111 1010 172 173 AD 1010 1101 255 123 { 7B 0111 1011 173 174 AE 1010 1110 256 124 | 7C 0111 1100 174 175 AF 1010 1111 257 125 } 7D 0111 1101 175 176 B0 1011 0000 260 126 ~ 7E 0111 1110 176 177 B1 1011 0001 261 127 DEL 7F 0111 1111 177 178 B2 1011 0010 262 128 80 1000 0000 200 179 B3 1011 0011 263 129 81 1000 0001 201 180 B4 1011 0100 264 130 82 1000 0010 202 181 B5 1011 0101 265 131 83 1000 0011 203 182 B6 1011 0110 266 132 84 1000 0100 204 183 B7 1011 0111 267 133 85 1000 0101 205 184 B8 1011 1000 270 134 86 1000 0110 206 185 B9 1011 1001 271 135 87 1000 0111 207 186 BA 1011 1010 272 136 88 1000 1000 210 187 BB 1011 1011 273 137 89 1000 1001 211 188 BC 1011 1100 274 138 8A 1000 1010 212 189 BD 1011 1101 275 139 8B 1000 1011 213 190 BE 1011 1110 276 140 8C 1000 1100 214 191 BF 1011 1111 277 141 8D 1000 1101 215 192 C0 1100 0000 300 142 8E 1000 1110 216 193 C1 1100 0001 301 143 8F 1000 1111 217 194 C2 1100 0010 302 144 90 1001 0000 220 195 C3 1100 0011 303 145 91 1001 0001 221 196 C4 1100 0100 304 146 92 1001 0010 222 197 C5 1100 0101 305 147 93 1001 0011 223 198 C6 1100 0110 306 148 94 1001 0100 224 199 C7 1100 0111 307 149 95 1001 0101 225 200 C8 1100 1000 310 150 96 1001 0110 226 201 C9 1100 1001 311 April 1989 MUG Notes Page 17 202 CA 1100 1010 312 253 FD 1111 1101 375 203 CB 1100 1011 313 254 FE 1111 1110 376 204 CC 1100 1100 314 255 FF 1111 1111 377 205 CD 1100 1101 315 206 CE 1100 1110 316 207 CF 1100 1111 317 208 D0 1101 0000 320 209 D1 1101 0001 321 210 D2 1101 0010 322 211 D3 1101 0011 323 212 D4 1101 0100 324 NUL - A Null character 213 D5 1101 0101 325 SOH - Start Of Header 214 D6 1101 0110 326 STX - Start Of teXt 215 D7 1101 0111 327 ETX - 216 D8 1101 1000 330 EOT - End Of teXt 217 D9 1101 1001 331 ENQ - ENQuiry 218 DA 1101 1010 332 ACK - ACKnowledge 219 DB 1101 1011 333 BEL - BELl 220 DC 1101 1100 334 BS - Back Space 221 DD 1101 1101 335 HT - Horizontal Tab 222 DE 1101 1110 336 LF - Line Feed 223 DF 1101 1111 337 VT - Vertical Tab 224 E0 1110 0000 340 FF - Form Feed 225 E1 1110 0001 341 CR - Carriage Return 226 E2 1110 0010 342 SO - Shift Out 227 E3 1110 0011 343 SI - Shift In 228 E4 1110 0100 344 DLE - DeLeTe 229 E5 1110 0101 345 DC1 - X-ON -start transmit 230 E6 1110 0110 346 DC2 231 E7 1110 0111 347 DC3 - X-OFF -stop transmit 232 E8 1110 1000 350 DC4 233 E9 1110 1001 351 NAK - Negative ACK 234 EA 1110 1010 352 SYN - 235 EB 1110 1011 353 ETB - 236 EC 1110 1100 354 CAN - CANcel 237 ED 1110 1101 355 EM - 238 EE 1110 1110 356 SUB - SUBstitute 239 EF 1110 1111 357 ESC - ESCape 240 F0 1111 0000 360 FS - Figures Shift 241 F1 1111 0001 361 GS - 242 F2 1111 0010 362 RS - 243 F3 1111 0011 363 244 F4 1111 0100 364 245 F5 1111 0101 365 246 F6 1111 0110 366 247 F7 1111 0111 367 248 F8 1111 1000 370 249 F9 1111 1001 371 250 FA 1111 1010 372 251 FB 1111 1011 373 252 FC 1111 1100 374 April 1989 MUG Notes Page 18 OPTIMIZING YOUR SYSTEM Recently, I tried some experiments on my system, to see if I could speed up floppy disk reads and writes. Remember, that I did this under OS-9 Level 2 using a Disto no-halt controller, and that any figures that you may come up with may not be exactly the same, but they should show about the same results. I played with the disk interleave. To explain: Your typical floppy on a Coco rotates at 300 rpm. We know that there are 18 sectors per track, (Think of a pie cut into 18 wedges.) and 35 or 40 or 80 tracks (cylinders) or concentric circles around the disk. When the disk rotates past the heads, the machine isn't fast enough to have the next 256 characters of data ready to write on the next sector as it comes past the head. So, there is a skip factor built in when you format a disk. By default, FORMAT (OS-9) or DSKINI (Disk Basic) write sector 1, then they skip room for a couple of sectors and then they number the next logical sector as 2 (its probably physical sector 4 on your system). If you could look at your disk and read the sector numbers as they rotated past the head, they would count 01, 07, 13, 02, 08, 14, 03, 09, 15, 04, 10, 16, 05, 11, 17, 06, 12, 18. I know that that is a strange way to count, even by my standards. You should have seen the pattern, write a sector, skip 2 and write the next and so it goes around the disk. All this time you probably thought that the sectors went 01, 02, 03, 04, 05 ... etc. What I did was to play with the number of sectors skipped (hence interleave). I finally settled on an interleave factor of two being the best factor for my system. (01, 10, 02, 11, 03, 12, 04, 13, 05, 14, 06, 15, 07, 16, 08, 17, 09, 18). Don't get hung up on the write, skip, write junk. Your operating system, be it OS-9, CoCo's Disk Basic and even heaven forbid MS-Dos all do it. When you ask to see sector 3, the operating system finds the sector numbered 3, even though it probably isn't the third physical sector on the track. I am including a chart of times to backup my claims. The first column is the interleave factor, the second is the time taken to format a 40 track double sided disk under OS-9, the third column is the time taken to copy a 96065 byte file from a ram disk to the floppy. (The times quoted come from my system hardware clock so they aren't affected by any halting of the CPU.) ILV | FORMAT | COPY | ---------------------------- 1 | 5:44 | 2:43 | 2 | 1:26 | :35 | 3 | 1:43 | :41 | 4 | 1:44 | :43 | 5 | 1:59 | :49 | 6 | 2:31 | 1:06 | 7 | 2:31 | 1:06 | ---------------------------- Yes folks, those times are minutes:seconds. You can see that if you were doing a large amount of reading or writing to floppy, you could save many seconds per day. Now I should do the same testing to my hard drive. Only problem is that it takes 45 minutes to format the hard drive, another 45 minutes for the verify pass, times several different interleave factors, I could have a full time job just trying to optimize the drive, not to mention keeping the floppy manufacturers in business supplying blank disks to hold the hard drive contents while I play around. Until the next time.... Stan. APRIL 1989 MUG Notes Page 19 GOODMAN'S GRUMBLINGS HOG WASH (A subtle warning about Hayes Modems) (Customer Support Policies) by Marty Goodman Please, when considering what modem to buy for yourself or your company, DO NOT BUY a modem made by Hayes. What follows is the story of why I feel this way so strongly: I recently purchased a Hayes (brand) V series 2400 baud modem in known dead condition. I spent about an hour figuring out what was wrong. A diode in the main power supply had blown and shorted out, causing an internal protective fuse to blow. I replaced the bad diode (a 50 cent part) and, for good measure, replaced the other 3 diodes in that part of the circuit. Testing the modem (with a temporary replacement fuse in place) it worked perfectly. The actual original fuse was a "subminiature" one with color code bands on it. Now, while the meaning of such bands on a resistor are known to all who repair or design computer hardware, their meaning on subminiature fuses is relatively obscure. Neither I nor three repair technicians I contacted knew what the bands on that fuse meant. Wanting to do a conscientious job of fixing the thing, I called up Hayes Microcomputer in Georgia,to request technical support info about exactly what the right replacement fuse was, and get a schematic for that power supply in case a problem arose again. I also wanted to get a parts sheet from Hayes so that I could order exact replacment parts if need be, because the Hayes modems are styled to fit into a very low profile case, and I might in some cases have problems fitting in generic replacement parts. I reached Hayes "Technical Support" on the phone, and requested a schematic diagram, parts list, and advise on the value of the blown fuse. Note carefully that I told them I had ALREADY fixed the modem, and merely wanted to make my repair professional. The response was a VERY curt "It is against company policy to give out any schematic information. It is against company policy to supply any (internal) parts to assist an owner with servicing their modem" I then said "OK.. but can you please tell me the value of that fuse, so I can go out and buy a replacement and get back on line in the next hour, instead of being without the modem for a week or more while you do a repair that would take me 5 minutes and cost me 50 cents." I received a very haughty reply that "HAYES doesn't do things like that". I later had confirmed by other calls from me and others that Hayes has a company policy of refusing to give out service information on their products. I want to make the public aware of this colossal arrogance on the part of Hayes corporation. I own, and on occasion have had to perform minor or even major repairs on products made or marketted by Epson, NEC, Tandy, Thompson, Amdek, Kodak, TEAC, Phillips, Magnavox, and other major brand names. In EVERY case with these other companies, the company in question was more than happy to sell me a service manual (complete with schematic and parts list), sell me replacement components, and in many cases have one of their repair technicians spend time with me on the phone helping me figure out the problem and fix it. Hayes insulting policy is the ONLY exception to this that I have yet encountered in a major name brand supplier of this sort of professional equipment. April 1989 MUG Notes Page 20 As it turned out, I later happened to discover a chart elaborating the color code for submiature fuses. (Tech types should note that the first three bands on the fuse give the amperage in milliamps. Thus, my fuse, which was oragne, black, red, was a 3000 milliamp fuse, or a 3 amp fuse. The fourth band (when present) is wider than the first three, and if red indicates the fuse is a fast blowing fuse. Mine was.) I also located locally a store that sold this exact type of fuse, and soon had the modem back together and working perfectly. I'm using it right now to transmit this message. I firmly believe that any company with a policy like that should not be patronized. If you have time, WRITE to them and TELL them what you think of their technical support policy. In the mean time, if you are considering buying a modem for yourself, please don't buy one made by Hayes! You can get far better prices, anyway, on quality Taiwan made modems. The Supra brand 2400 baud modem (advertised in Computer Shopper for as low as $140) is one of the finest around. If for some reason you want to buy an American made product, try US Robotics, Teledata, or such. Note that part of Hayes' successful sales campaign that lets them sell their overpriced products is that they offer prompt repair services. What the prospective buyer does not consider is that for the price, they could usually buy TWO (or even in some cases THREE) other brand modems, and just keep one as a spare, plugging it in instantly should the first fail. Hayes's other advertising point is that their modems are especially reliable and rugged. I don't believe a word of that. I did the repairs on this modem (which failed in the field, by the way!) and saw nothing especially wonderful about the circuit design or the parts used. They were in no way especially different from the innards of other (far lower priced) brands of comparable modems. So... don't be fooled... and don't do business with such an arrogant company! DON'T BUY HAYES PRODUCTS! Further Notes: Some may argue that Hayes needs to keep its designs secret in an effort to thwart those who would steal their design. Although this argument seems plausible at first, I believe it to be nonsense. Almost NO other major supplier of home and commercial electronic equipment refuses to provide such information. Clearly THOSE other ones haven't gone out of bueiness due to their revelations of service information. I certainly am not in favor of theft of intellectual property. But by refusing to supply private owners with service manuals, Hayes only hurts its legitimate customers. Would be thieves can easily "reverse engineer" (analyze the working of) a Hayes product. The lack of service information for such would be no more than a minor inconvenience. It is true that Hayes has a good reputation for the speed and courtesy of its service department. However, company on site service, however fast and reasonably priced, can NEVER be a substitute for the owner having the info needed to make his OWN repairs on site. *I* (any competent technician) can often get a broken piece of equipment up and running within a few minutes to an hour of its failure, especially when aided by proper service information. There is NO WAY that Hayes can offer that kind of speed of restoration of service via any kind of Atlanta based service facility! By their refuseal to provide service info, they decrease the value of their products significantly by making them harder to repair. This essay is in the public domain. PLEASE feel free to post it as widely as possible. ** Appeared on Delphi Feb 7 1989, and MidNight R.D.S. Feb 8 1989 ** April 1989 MUG Notes Page 21 Tech Tips by W. Morrison It has been at least a couple of years now since Intertan has made a modem with the four pin DIN connector. Third party modem makers have never made them that way. At this point in time, we seem to have a relatively large number of new people wishing to go on-line with their CoCo's and it appears to be time to re-do the "how to's" of making your own modem cable for the CoCo series of computers. This is actually a good project to start with as the parts list is quite short and the work involved is not intensive. On the other hand, there is both money and peace of mind to be saved as the proper cable from Radio Shack is worth almost thirty dollars, and it is not available in all Radio Shack stores! Lets start with the parts list. You will need three components, which can all be bought at a Radio Shack, or from whatever electronics part store you may happen to frequent. I am including the Tandy part numbers to help the new-comers, just in case you are not sure what you are looking for. You will need; 1 serial printer cable (26-3020) $6.95 1 male DB 25 connector (276-1547) $5.99 1 DB 25 plastic hood (276-1536) $2.99 Once you have these components, you start out by cutting the connector off of one end of the printer serial cable. Then strip off the insulation and expose the bare copper conductors on each of the wires in the cable. Next solder each of the four wires to the corresponding terminal on the DB 25 connector as per the chart below. When you are done with this, install the hood over the DB 25 connector and that is it. Plug the DB 25 end of the cable into the back of the modem and the other end into the serial port on the CoCo. With the proper choice of software and settings, you should now be ready to go on line. PIN CONNECTIONS 4 pin DIN to DB 25 pin 1 to pin 8 pin 2 to pin 3 pin 3 to pin 7 pin 4 to pin 2 There is one further note to make. If you have an auto dial/answer modem, you have to set the switch inside the modem to forced DTR. Your owners manual should be able to show you which switch this is and when it is in the on position. ********************************************************* * * * The Next Meeting of * * * * M U G * * * * Will be at The * * London Public Library * * Main Branch * * On * * Tuesday May 9 * * Starting 6:30 P.M. * * * ********************************************************* April 1989 MUG Notes Page 22 For you horoscope fans this is a humour article for those signs who know who they are and this could be fun to read to your friends who think they are perfect. Have fun with it. ARIES (March 21 - April 19) A strange shifting in the stars may cause you to experience some pleasure while viewing a rerun of Sheriff Lobo. Do not worry. This is only an illusion, and will pass, like a cheap meal. Do not treat your lovemaking as a hobby or you could do yourself permanent damage with wrongful applications of model airplane glue. LIBRA (September 23 - October 23) The position of YANK, the main star influencing your destiny, advises that now is the time for a torrid romantic fling. However, the position of the Moral Majority condems a torrid romantic fling as a no-no. The choice is yours. Either be bored out of your skull on Earth, or burn for all eternity in Hell ! TAURUS (April 20 - May 20) Your enthusiasm is contagious, and so is your rash, so lay off the romantic entanglements. Complete one project before beginning a second. However, it is not necessary to complete one project if you're planning to move directly on to a third. Your grades can improve overnight, providing you write legibly on your forearm. GEMINI (May 21 - June 21) After years of diligent brown-nosing, you rise to the upper echelons of corporate power. Too bad your company is about to go under ! This is typical of the way your luck has been running recently and will continue to run for some time. Do not fret ! You still have a lot of drive left in you. Take a trip to Chicago ! CANCER (June 22 - July 22) The position of your stars is identical to those of Aquarius, Capricorn and Sagittarius. How this can be, we don't know. (But it does go a long way in explaining your lack of originality in life !) We suggest that from now on you read those three horoscopes and then pick out any advice you think looks good to you. LEO (July 23 - August 22) Your main stars have shifted in such a way that, when connected by straight lines, they strongly resemble either a profile of Brian Mulroney or an aerial view of Newfoundland. (This is open to artistic interpretation.) Such a configuration strongly suggests that you will soon be overtaken by a desire to invade the refrigerator. SCORPIO (October 24 - November 21) A good day ! An annoying neighbour will cease to bother you, as you are evicted in the A.M. Improve your personal ties by throwing out the very wide ones with the polka dot prints. Nobody has been wearing them for years. Look for your mailbox to be flooded with letters as someone pours an entire can of alphabet soup in it. April 1989 MUG Notes Page 23 SAGITTARIUS (November 22 - December 21) A study of your stars has failed to uncover any information about your future. This could mean that you have no future. In fact, it's quite possible that you recently passed away, and your loved ones have been derelict in making the proper arrangements. Seek the advice of an expert, however, before having yourself cremated. CAPRICORN (December 22 - January 19) Take a chance on a new co-worker. Ther'ye only a dollar each and, who knows, you may just win her ! The AM may seem horrible today, however it will begin to look better once you see what the PM has in store for you. An unexpected raise and promotion at work enables you to pay for your emergency brain surgery. AQUARIUS (January 20 - February 18) Your Moon has very quietly moved from the House of Leo to the Condominium of Stanley. (Tax Purposes.) This signals a dramatic upheaval in your emotional state. Warm thought will singe youur brain. Because Uranus and your piles are one, you could be in big danger. Beware of fools, envious of your many shortcomings. PISCES (February 19 - March 20) A sensational day ! An unexpected romance blooms out of a chance encounter at a local vigilante meeting. Be frank with your boss. That way, when you screw up, he will fire Frank and not you. Put your priorities in alphabetical order and stop accepting second best. It's much too good for you. VIRGO (August 23 - September 22) Give a hand at home. Get ahead at work. Give a passing stranger the eye, and a passing motorist the finger. Lose an arm and a leg at the track. Get something off your chest. Lend your ears to fellow countrymen. Stick your nose in other people's business. Get your ass in a sling. Put your foot in your mouth. Hang loose.